diff options
Diffstat (limited to 'drivers/fsi')
| -rw-r--r-- | drivers/fsi/Kconfig | 26 | ||||
| -rw-r--r-- | drivers/fsi/Makefile | 3 | ||||
| -rw-r--r-- | drivers/fsi/fsi-core.c | 841 | ||||
| -rw-r--r-- | drivers/fsi/fsi-master-gpio.c | 604 | ||||
| -rw-r--r-- | drivers/fsi/fsi-master-hub.c | 327 | ||||
| -rw-r--r-- | drivers/fsi/fsi-master.h | 43 | ||||
| -rw-r--r-- | drivers/fsi/fsi-scom.c | 263 |
7 files changed, 2107 insertions, 0 deletions
diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig index 04c1a0efa7a7..6821ed0cd5e8 100644 --- a/drivers/fsi/Kconfig +++ b/drivers/fsi/Kconfig @@ -6,7 +6,33 @@ menu "FSI support" config FSI tristate "FSI support" + select CRC4 ---help--- FSI - the FRU Support Interface - is a simple bus for low-level access to POWER-based hardware. + +if FSI + +config FSI_MASTER_GPIO + tristate "GPIO-based FSI master" + depends on GPIOLIB + select CRC4 + ---help--- + This option enables a FSI master driver using GPIO lines. + +config FSI_MASTER_HUB + tristate "FSI hub master" + ---help--- + This option enables a FSI hub master driver. Hub is a type of FSI + master that is connected to the upstream master via a slave. Hubs + allow chaining of FSI links to an arbitrary depth. This allows for + a high target device fanout. + +config FSI_SCOM + tristate "SCOM FSI client device driver" + ---help--- + This option enables an FSI based SCOM device driver. + +endif + endmenu diff --git a/drivers/fsi/Makefile b/drivers/fsi/Makefile index db0e5e7c1655..65eb99dfafdb 100644 --- a/drivers/fsi/Makefile +++ b/drivers/fsi/Makefile @@ -1,2 +1,5 @@ obj-$(CONFIG_FSI) += fsi-core.o +obj-$(CONFIG_FSI_MASTER_HUB) += fsi-master-hub.o +obj-$(CONFIG_FSI_MASTER_GPIO) += fsi-master-gpio.o +obj-$(CONFIG_FSI_SCOM) += fsi-scom.o diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c index 3d55bd547178..a485864cb512 100644 --- a/drivers/fsi/fsi-core.c +++ b/drivers/fsi/fsi-core.c @@ -13,9 +13,830 @@ * GNU General Public License for more details. */ +#include <linux/crc4.h> #include <linux/device.h> #include <linux/fsi.h> +#include <linux/idr.h> #include <linux/module.h> +#include <linux/slab.h> +#include <linux/bitops.h> + +#include "fsi-master.h" + +#define CREATE_TRACE_POINTS +#include <trace/events/fsi.h> + +#define FSI_SLAVE_CONF_NEXT_MASK GENMASK(31, 31) +#define FSI_SLAVE_CONF_SLOTS_MASK GENMASK(23, 16) +#define FSI_SLAVE_CONF_SLOTS_SHIFT 16 +#define FSI_SLAVE_CONF_VERSION_MASK GENMASK(15, 12) +#define FSI_SLAVE_CONF_VERSION_SHIFT 12 +#define FSI_SLAVE_CONF_TYPE_MASK GENMASK(11, 4) +#define FSI_SLAVE_CONF_TYPE_SHIFT 4 +#define FSI_SLAVE_CONF_CRC_SHIFT 4 +#define FSI_SLAVE_CONF_CRC_MASK GENMASK(3, 0) +#define FSI_SLAVE_CONF_DATA_BITS 28 + +#define FSI_PEEK_BASE 0x410 + +static const int engine_page_size = 0x400; + +#define FSI_SLAVE_BASE 0x800 + +/* + * FSI slave engine control register offsets + */ +#define FSI_SMODE 0x0 /* R/W: Mode register */ +#define FSI_SISC 0x8 /* R/W: Interrupt condition */ +#define FSI_SSTAT 0x14 /* R : Slave status */ +#define FSI_LLMODE 0x100 /* R/W: Link layer mode register */ + +/* + * SMODE fields + */ +#define FSI_SMODE_WSC 0x80000000 /* Warm start done */ +#define FSI_SMODE_ECRC 0x20000000 /* Hw CRC check */ +#define FSI_SMODE_SID_SHIFT 24 /* ID shift */ +#define FSI_SMODE_SID_MASK 3 /* ID Mask */ +#define FSI_SMODE_ED_SHIFT 20 /* Echo delay shift */ +#define FSI_SMODE_ED_MASK 0xf /* Echo delay mask */ +#define FSI_SMODE_SD_SHIFT 16 /* Send delay shift */ +#define FSI_SMODE_SD_MASK 0xf /* Send delay mask */ +#define FSI_SMODE_LBCRR_SHIFT 8 /* Clk ratio shift */ +#define FSI_SMODE_LBCRR_MASK 0xf /* Clk ratio mask */ + +/* + * LLMODE fields + */ +#define FSI_LLMODE_ASYNC 0x1 + +#define FSI_SLAVE_SIZE_23b 0x800000 + +static DEFINE_IDA(master_ida); + +struct fsi_slave { + struct device dev; + struct fsi_master *master; + int id; + int link; + uint32_t size; /* size of slave address space */ +}; + +#define to_fsi_master(d) container_of(d, struct fsi_master, dev) +#define to_fsi_slave(d) container_of(d, struct fsi_slave, dev) + +static const int slave_retries = 2; +static int discard_errors; + +static int fsi_master_read(struct fsi_master *master, int link, + uint8_t slave_id, uint32_t addr, void *val, size_t size); +static int fsi_master_write(struct fsi_master *master, int link, + uint8_t slave_id, uint32_t addr, const void *val, size_t size); +static int fsi_master_break(struct fsi_master *master, int link); + +/* + * fsi_device_read() / fsi_device_write() / fsi_device_peek() + * + * FSI endpoint-device support + * + * Read / write / peek accessors for a client + * + * Parameters: + * dev: Structure passed to FSI client device drivers on probe(). + * addr: FSI address of given device. Client should pass in its base address + * plus desired offset to access its register space. + * val: For read/peek this is the value read at the specified address. For + * write this is value to write to the specified address. + * The data in val must be FSI bus endian (big endian). + * size: Size in bytes of the operation. Sizes supported are 1, 2 and 4 bytes. + * Addresses must be aligned on size boundaries or an error will result. + */ +int fsi_device_read(struct fsi_device *dev, uint32_t addr, void *val, + size_t size) +{ + if (addr > dev->size || size > dev->size || addr > dev->size - size) + return -EINVAL; + + return fsi_slave_read(dev->slave, dev->addr + addr, val, size); +} +EXPORT_SYMBOL_GPL(fsi_device_read); + +int fsi_device_write(struct fsi_device *dev, uint32_t addr, const void *val, + size_t size) +{ + if (addr > dev->size || size > dev->size || addr > dev->size - size) + return -EINVAL; + + return fsi_slave_write(dev->slave, dev->addr + addr, val, size); +} +EXPORT_SYMBOL_GPL(fsi_device_write); + +int fsi_device_peek(struct fsi_device *dev, void *val) +{ + uint32_t addr = FSI_PEEK_BASE + ((dev->unit - 2) * sizeof(uint32_t)); + + return fsi_slave_read(dev->slave, addr, val, sizeof(uint32_t)); +} + +static void fsi_device_release(struct device *_device) +{ + struct fsi_device *device = to_fsi_dev(_device); + + kfree(device); +} + +static struct fsi_device *fsi_create_device(struct fsi_slave *slave) +{ + struct fsi_device *dev; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) + return NULL; + + dev->dev.parent = &slave->dev; + dev->dev.bus = &fsi_bus_type; + dev->dev.release = fsi_device_release; + + return dev; +} + +/* FSI slave support */ +static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp, + uint8_t *idp) +{ + uint32_t addr = *addrp; + uint8_t id = *idp; + + if (addr > slave->size) + return -EINVAL; + + /* For 23 bit addressing, we encode the extra two bits in the slave + * id (and the slave's actual ID needs to be 0). + */ + if (addr > 0x1fffff) { + if (slave->id != 0) + return -EINVAL; + id = (addr >> 21) & 0x3; + addr &= 0x1fffff; + } + + *addrp = addr; + *idp = id; + return 0; +} + +int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) +{ + struct fsi_master *master = slave->master; + uint32_t irq, stat; + int rc, link; + uint8_t id; + + link = slave->link; + id = slave->id; + + rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC, + &irq, sizeof(irq)); + if (rc) + return rc; + + rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT, + &stat, sizeof(stat)); + if (rc) + return rc; + + dev_info(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", + be32_to_cpu(stat), be32_to_cpu(irq)); + + /* clear interrupts */ + return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC, + &irq, sizeof(irq)); +} + +static int fsi_slave_set_smode(struct fsi_master *master, int link, int id); + +int fsi_slave_handle_error(struct fsi_slave *slave, bool write, uint32_t addr, + size_t size) +{ + struct fsi_master *master = slave->master; + int rc, link; + uint32_t reg; + uint8_t id; + + if (discard_errors) + return -1; + + link = slave->link; + id = slave->id; + + dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]", + write ? "write" : "read", addr, size); + + /* try a simple clear of error conditions, which may fail if we've lost + * communication with the slave + */ + rc = fsi_slave_report_and_clear_errors(slave); + if (!rc) + return 0; + + /* send a TERM and retry */ + if (master->term) { + rc = master->term(master, link, id); + if (!rc) { + rc = fsi_master_read(master, link, id, 0, + ®, sizeof(reg)); + if (!rc) + rc = fsi_slave_report_and_clear_errors(slave); + if (!rc) + return 0; + } + } + + /* getting serious, reset the slave via BREAK */ + rc = fsi_master_break(master, link); + if (rc) + return rc; + + rc = fsi_slave_set_smode(master, link, id); + if (rc) + return rc; + + return fsi_slave_report_and_clear_errors(slave); +} + +int fsi_slave_read(struct fsi_slave *slave, uint32_t addr, + void *val, size_t size) +{ + uint8_t id = slave->id; + int rc, err_rc, i; + + rc = fsi_slave_calc_addr(slave, &addr, &id); + if (rc) + return rc; + + for (i = 0; i < slave_retries; i++) { + rc = fsi_master_read(slave->master, slave->link, + id, addr, val, size); + if (!rc) + break; + + err_rc = fsi_slave_handle_error(slave, false, addr, size); + if (err_rc) + break; + } + + return rc; +} +EXPORT_SYMBOL_GPL(fsi_slave_read); + +int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, + const void *val, size_t size) +{ + uint8_t id = slave->id; + int rc, err_rc, i; + + rc = fsi_slave_calc_addr(slave, &addr, &id); + if (rc) + return rc; + + for (i = 0; i < slave_retries; i++) { + rc = fsi_master_write(slave->master, slave->link, + id, addr, val, size); + if (!rc) + break; + + err_rc = fsi_slave_handle_error(slave, true, addr, size); + if (err_rc) + break; + } + + return rc; +} +EXPORT_SYMBOL_GPL(fsi_slave_write); + +extern int fsi_slave_claim_range(struct fsi_slave *slave, + uint32_t addr, uint32_t size) +{ + if (addr + size < addr) + return -EINVAL; + + if (addr + size > slave->size) + return -EINVAL; + + /* todo: check for overlapping claims */ + return 0; +} +EXPORT_SYMBOL_GPL(fsi_slave_claim_range); + +extern void fsi_slave_release_range(struct fsi_slave *slave, + uint32_t addr, uint32_t size) +{ +} +EXPORT_SYMBOL_GPL(fsi_slave_release_range); + +static int fsi_slave_scan(struct fsi_slave *slave) +{ + uint32_t engine_addr; + uint32_t conf; + int rc, i; + + /* + * scan engines + * + * We keep the peek mode and slave engines for the core; so start + * at the third slot in the configuration table. We also need to + * skip the chip ID entry at the start of the address space. + */ + engine_addr = engine_page_size * 3; + for (i = 2; i < engine_page_size / sizeof(uint32_t); i++) { + uint8_t slots, version, type, crc; + struct fsi_device *dev; + + rc = fsi_slave_read(slave, (i + 1) * sizeof(conf), + &conf, sizeof(conf)); + if (rc) { + dev_warn(&slave->dev, + "error reading slave registers\n"); + return -1; + } + conf = be32_to_cpu(conf); + + crc = crc4(0, conf, 32); + if (crc) { + dev_warn(&slave->dev, + "crc error in slave register at 0x%04x\n", + i); + return -1; + } + + slots = (conf & FSI_SLAVE_CONF_SLOTS_MASK) + >> FSI_SLAVE_CONF_SLOTS_SHIFT; + version = (conf & FSI_SLAVE_CONF_VERSION_MASK) + >> FSI_SLAVE_CONF_VERSION_SHIFT; + type = (conf & FSI_SLAVE_CONF_TYPE_MASK) + >> FSI_SLAVE_CONF_TYPE_SHIFT; + + /* + * Unused address areas are marked by a zero type value; this + * skips the defined address areas + */ + if (type != 0 && slots != 0) { + + /* create device */ + dev = fsi_create_device(slave); + if (!dev) + return -ENOMEM; + + dev->slave = slave; + dev->engine_type = type; + dev->version = version; + dev->unit = i; + dev->addr = engine_addr; + dev->size = slots * engine_page_size; + + dev_dbg(&slave->dev, + "engine[%i]: type %x, version %x, addr %x size %x\n", + dev->unit, dev->engine_type, version, + dev->addr, dev->size); + + dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x", + slave->master->idx, slave->link, + slave->id, i - 2); + + rc = device_register(&dev->dev); + if (rc) { + dev_warn(&slave->dev, "add failed: %d\n", rc); + put_device(&dev->dev); + } + } + + engine_addr += slots * engine_page_size; + + if (!(conf & FSI_SLAVE_CONF_NEXT_MASK)) + break; + } + + return 0; +} + +static ssize_t fsi_slave_sysfs_raw_read(struct file *file, + struct kobject *kobj, struct bin_attribute *attr, char *buf, + loff_t off, size_t count) +{ + struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); + size_t total_len, read_len; + int rc; + + if (off < 0) + return -EINVAL; + + if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) + return -EINVAL; + + for (total_len = 0; total_len < count; total_len += read_len) { + read_len = min_t(size_t, count, 4); + read_len -= off & 0x3; + + rc = fsi_slave_read(slave, off, buf + total_len, read_len); + if (rc) + return rc; + + off += read_len; + } + + return count; +} + +static ssize_t fsi_slave_sysfs_raw_write(struct file *file, + struct kobject *kobj, struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); + size_t total_len, write_len; + int rc; + + if (off < 0) + return -EINVAL; + + if (off > 0xffffffff || count > 0xffffffff || off + count > 0xffffffff) + return -EINVAL; + + for (total_len = 0; total_len < count; total_len += write_len) { + write_len = min_t(size_t, count, 4); + write_len -= off & 0x3; + + rc = fsi_slave_write(slave, off, buf + total_len, write_len); + if (rc) + return rc; + + off += write_len; + } + + return count; +} + +static struct bin_attribute fsi_slave_raw_attr = { + .attr = { + .name = "raw", + .mode = 0600, + }, + .size = 0, + .read = fsi_slave_sysfs_raw_read, + .write = fsi_slave_sysfs_raw_write, +}; + +static ssize_t fsi_slave_sysfs_term_write(struct file *file, + struct kobject *kobj, struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct fsi_slave *slave = to_fsi_slave(kobj_to_dev(kobj)); + struct fsi_master *master = slave->master; + + if (!master->term) + return -ENODEV; + + master->term(master, slave->link, slave->id); + return count; +} + +static struct bin_attribute fsi_slave_term_attr = { + .attr = { + .name = "term", + .mode = 0200, + }, + .size = 0, + .write = fsi_slave_sysfs_term_write, +}; + +/* Encode slave local bus echo delay */ +static inline uint32_t fsi_smode_echodly(int x) +{ + return (x & FSI_SMODE_ED_MASK) << FSI_SMODE_ED_SHIFT; +} + +/* Encode slave local bus send delay */ +static inline uint32_t fsi_smode_senddly(int x) +{ + return (x & FSI_SMODE_SD_MASK) << FSI_SMODE_SD_SHIFT; +} + +/* Encode slave local bus clock rate ratio */ +static inline uint32_t fsi_smode_lbcrr(int x) +{ + return (x & FSI_SMODE_LBCRR_MASK) << FSI_SMODE_LBCRR_SHIFT; +} + +/* Encode slave ID */ +static inline uint32_t fsi_smode_sid(int x) +{ + return (x & FSI_SMODE_SID_MASK) << FSI_SMODE_SID_SHIFT; +} + +static const uint32_t fsi_slave_smode(int id) +{ + return FSI_SMODE_WSC | FSI_SMODE_ECRC + | fsi_smode_sid(id) + | fsi_smode_echodly(0xf) | fsi_smode_senddly(0xf) + | fsi_smode_lbcrr(0x8); +} + +static int fsi_slave_set_smode(struct fsi_master *master, int link, int id) +{ + uint32_t smode; + + /* set our smode register with the slave ID field to 0; this enables + * extended slave addressing + */ + smode = fsi_slave_smode(id); + smode = cpu_to_be32(smode); + + return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SMODE, + &smode, sizeof(smode)); +} + +static void fsi_slave_release(struct device *dev) +{ + struct fsi_slave *slave = to_fsi_slave(dev); + + kfree(slave); +} + +static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) +{ + uint32_t chip_id, llmode; + struct fsi_slave *slave; + uint8_t crc; + int rc; + + /* Currently, we only support single slaves on a link, and use the + * full 23-bit address range + */ + if (id != 0) + return -EINVAL; + + rc = fsi_master_read(master, link, id, 0, &chip_id, sizeof(chip_id)); + if (rc) { + dev_dbg(&master->dev, "can't read slave %02x:%02x %d\n", + link, id, rc); + return -ENODEV; + } + chip_id = be32_to_cpu(chip_id); + + crc = crc4(0, chip_id, 32); + if (crc) { + dev_warn(&master->dev, "slave %02x:%02x invalid chip id CRC!\n", + link, id); + return -EIO; + } + + dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", + chip_id, master->idx, link, id); + + rc = fsi_slave_set_smode(master, link, id); + if (rc) { + dev_warn(&master->dev, + "can't set smode on slave:%02x:%02x %d\n", + link, id, rc); + return -ENODEV; + } + + /* If we're behind a master that doesn't provide a self-running bus + * clock, put the slave into async mode + */ + if (master->flags & FSI_MASTER_FLAG_SWCLOCK) { + llmode = cpu_to_be32(FSI_LLMODE_ASYNC); + rc = fsi_master_write(master, link, id, + FSI_SLAVE_BASE + FSI_LLMODE, + &llmode, sizeof(llmode)); + if (rc) + dev_warn(&master->dev, + "can't set llmode on slave:%02x:%02x %d\n", + link, id, rc); + } + + /* We can communicate with a slave; create the slave device and + * register. + */ + slave = kzalloc(sizeof(*slave), GFP_KERNEL); + if (!slave) + return -ENOMEM; + + slave->master = master; + slave->dev.parent = &master->dev; + slave->dev.release = fsi_slave_release; + slave->link = link; + slave->id = id; + slave->size = FSI_SLAVE_SIZE_23b; + + dev_set_name(&slave->dev, "slave@%02x:%02x", link, id); + rc = device_register(&slave->dev); + if (rc < 0) { + dev_warn(&master->dev, "failed to create slave device: %d\n", + rc); + put_device(&slave->dev); + return rc; + } + + rc = device_create_bin_file(&slave->dev, &fsi_slave_raw_attr); + if (rc) + dev_warn(&slave->dev, "failed to create raw attr: %d\n", rc); + + rc = device_create_bin_file(&slave->dev, &fsi_slave_term_attr); + if (rc) + dev_warn(&slave->dev, "failed to create term attr: %d\n", rc); + + rc = fsi_slave_scan(slave); + if (rc) + dev_dbg(&master->dev, "failed during slave scan with: %d\n", + rc); + + return rc; +} + +/* FSI master support */ +static int fsi_check_access(uint32_t addr, size_t size) +{ + if (size != 1 && size != 2 && size != 4) + return -EINVAL; + + if ((addr & 0x3) != (size & 0x3)) + return -EINVAL; + + return 0; +} + +static int fsi_master_read(struct fsi_master *master, int link, + uint8_t slave_id, uint32_t addr, void *val, size_t size) +{ + int rc; + + trace_fsi_master_read(master, link, slave_id, addr, size); + + rc = fsi_check_access(addr, size); + if (!rc) + rc = master->read(master, link, slave_id, addr, val, size); + + trace_fsi_master_rw_result(master, link, slave_id, addr, size, + false, val, rc); + + return rc; +} + +static int fsi_master_write(struct fsi_master *master, int link, + uint8_t slave_id, uint32_t addr, const void *val, size_t size) +{ + int rc; + + trace_fsi_master_write(master, link, slave_id, addr, size, val); + + rc = fsi_check_access(addr, size); + if (!rc) + rc = master->write(master, link, slave_id, addr, val, size); + + trace_fsi_master_rw_result(master, link, slave_id, addr, size, + true, val, rc); + + return rc; +} + +static int fsi_master_link_enable(struct fsi_master *master, int link) +{ + if (master->link_enable) + return master->link_enable(master, link); + + return 0; +} + +/* + * Issue a break command on this link + */ +static int fsi_master_break(struct fsi_master *master, int link) +{ + trace_fsi_master_break(master, link); + + if (master->send_break) + return master->send_break(master, link); + + return 0; +} + +static int fsi_master_scan(struct fsi_master *master) +{ + int link, rc; + + for (link = 0; link < master->n_links; link++) { + rc = fsi_master_link_enable(master, link); + if (rc) { + dev_dbg(&master->dev, + "enable link %d failed: %d\n", link, rc); + continue; + } + rc = fsi_master_break(master, link); + if (rc) { + dev_dbg(&master->dev, + "break to link %d failed: %d\n", link, rc); + continue; + } + + fsi_slave_init(master, link, 0); + } + + return 0; +} + +static int fsi_slave_remove_device(struct device *dev, void *arg) +{ + device_unregister(dev); + return 0; +} + +static int fsi_master_remove_slave(struct device *dev, void *arg) +{ + device_for_each_child(dev, NULL, fsi_slave_remove_device); + device_unregister(dev); + return 0; +} + +static void fsi_master_unscan(struct fsi_master *master) +{ + device_for_each_child(&master->dev, NULL, fsi_master_remove_slave); +} + +static ssize_t master_rescan_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct fsi_master *master = to_fsi_master(dev); + int rc; + + fsi_master_unscan(master); + rc = fsi_master_scan(master); + if (rc < 0) + return rc; + + return count; +} + +static DEVICE_ATTR(rescan, 0200, NULL, master_rescan_store); + +static ssize_t master_break_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct fsi_master *master = to_fsi_master(dev); + + fsi_master_break(master, 0); + + return count; +} + +static DEVICE_ATTR(break, 0200, NULL, master_break_store); + +int fsi_master_register(struct fsi_master *master) +{ + int rc; + + if (!master) + return -EINVAL; + + master->idx = ida_simple_get(&master_ida, 0, INT_MAX, GFP_KERNEL); + dev_set_name(&master->dev, "fsi%d", master->idx); + + rc = device_register(&master->dev); + if (rc) { + ida_simple_remove(&master_ida, master->idx); + return rc; + } + + rc = device_create_file(&master->dev, &dev_attr_rescan); + if (rc) { + device_unregister(&master->dev); + ida_simple_remove(&master_ida, master->idx); + return rc; + } + + rc = device_create_file(&master->dev, &dev_attr_break); + if (rc) { + device_unregister(&master->dev); + ida_simple_remove(&master_ida, master->idx); + return rc; + } + + fsi_master_scan(master); + + return 0; +} +EXPORT_SYMBOL_GPL(fsi_master_register); + +void fsi_master_unregister(struct fsi_master *master) +{ + if (master->idx >= 0) { + ida_simple_remove(&master_ida, master->idx); + master->idx = -1; + } + + fsi_master_unscan(master); + device_unregister(&master->dev); +} +EXPORT_SYMBOL_GPL(fsi_master_unregister); /* FSI core & Linux bus type definitions */ @@ -39,6 +860,23 @@ static int fsi_bus_match(struct device *dev, struct device_driver *drv) return 0; } +int fsi_driver_register(struct fsi_driver *fsi_drv) +{ + if (!fsi_drv) + return -EINVAL; + if (!fsi_drv->id_table) + return -EINVAL; + + return driver_register(&fsi_drv->drv); +} +EXPORT_SYMBOL_GPL(fsi_driver_register); + +void fsi_driver_unregister(struct fsi_driver *fsi_drv) +{ + driver_unregister(&fsi_drv->drv); +} +EXPORT_SYMBOL_GPL(fsi_driver_unregister); + struct bus_type fsi_bus_type = { .name = "fsi", .match = fsi_bus_match, @@ -57,3 +895,6 @@ static void fsi_exit(void) module_init(fsi_init); module_exit(fsi_exit); +module_param(discard_errors, int, 0664); +MODULE_LICENSE("GPL"); +MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses"); diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c new file mode 100644 index 000000000000..ae2618768508 --- /dev/null +++ b/drivers/fsi/fsi-master-gpio.c @@ -0,0 +1,604 @@ +/* + * A FSI master controller, using a simple GPIO bit-banging interface + */ + +#include <linux/crc4.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/fsi.h> +#include <linux/gpio/consumer.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include "fsi-master.h" + +#define FSI_GPIO_STD_DLY 1 /* Standard pin delay in nS */ +#define FSI_ECHO_DELAY_CLOCKS 16 /* Number clocks for echo delay */ +#define FSI_PRE_BREAK_CLOCKS 50 /* Number clocks to prep for break */ +#define FSI_BREAK_CLOCKS 256 /* Number of clocks to issue break */ +#define FSI_POST_BREAK_CLOCKS 16000 /* Number clocks to set up cfam */ +#define FSI_INIT_CLOCKS 5000 /* Clock out any old data */ +#define FSI_GPIO_STD_DELAY 10 /* Standard GPIO delay in nS */ + /* todo: adjust down as low as */ + /* possible or eliminate */ +#define FSI_GPIO_CMD_DPOLL 0x2 +#define FSI_GPIO_CMD_TERM 0x3f +#define FSI_GPIO_CMD_ABS_AR 0x4 + +#define FSI_GPIO_DPOLL_CLOCKS 100 /* < 21 will cause slave to hang */ + +/* Bus errors */ +#define FSI_GPIO_ERR_BUSY 1 /* Slave stuck in busy state */ +#define FSI_GPIO_RESP_ERRA 2 /* Any (misc) Error */ +#define FSI_GPIO_RESP_ERRC 3 /* Slave reports master CRC error */ +#define FSI_GPIO_MTOE 4 /* Master time out error */ +#define FSI_GPIO_CRC_INVAL 5 /* Master reports slave CRC error */ + +/* Normal slave responses */ +#define FSI_GPIO_RESP_BUSY 1 +#define FSI_GPIO_RESP_ACK 0 +#define FSI_GPIO_RESP_ACKD 4 + +#define FSI_GPIO_MAX_BUSY 100 +#define FSI_GPIO_MTOE_COUNT 1000 +#define FSI_GPIO_DRAIN_BITS 20 +#define FSI_GPIO_CRC_SIZE 4 +#define FSI_GPIO_MSG_ID_SIZE 2 +#define FSI_GPIO_MSG_RESPID_SIZE 2 +#define FSI_GPIO_PRIME_SLAVE_CLOCKS 100 + +struct fsi_master_gpio { + struct fsi_master master; + struct device *dev; + spinlock_t cmd_lock; /* Lock for commands */ + struct gpio_desc *gpio_clk; + struct gpio_desc *gpio_data; + struct gpio_desc *gpio_trans; /* Voltage translator */ + struct gpio_desc *gpio_enable; /* FSI enable */ + struct gpio_desc *gpio_mux; /* Mux control */ +}; + +#define CREATE_TRACE_POINTS +#include <trace/events/fsi_master_gpio.h> + +#define to_fsi_master_gpio(m) container_of(m, struct fsi_master_gpio, master) + +struct fsi_gpio_msg { + uint64_t msg; + uint8_t bits; +}; + +static void clock_toggle(struct fsi_master_gpio *master, int count) +{ + int i; + + for (i = 0; i < count; i++) { + ndelay(FSI_GPIO_STD_DLY); + gpiod_set_value(master->gpio_clk, 0); + ndelay(FSI_GPIO_STD_DLY); + gpiod_set_value(master->gpio_clk, 1); + } +} + +static int sda_in(struct fsi_master_gpio *master) +{ + int in; + + ndelay(FSI_GPIO_STD_DLY); + in = gpiod_get_value(master->gpio_data); + return in ? 1 : 0; +} + +static void sda_out(struct fsi_master_gpio *master, int value) +{ + gpiod_set_value(master->gpio_data, value); +} + +static void set_sda_input(struct fsi_master_gpio *master) +{ + gpiod_direction_input(master->gpio_data); + gpiod_set_value(master->gpio_trans, 0); +} + +static void set_sda_output(struct fsi_master_gpio *master, int value) +{ + gpiod_set_value(master->gpio_trans, 1); + gpiod_direction_output(master->gpio_data, value); +} + +static void clock_zeros(struct fsi_master_gpio *master, int count) +{ + set_sda_output(master, 1); + clock_toggle(master, count); +} + +static void serial_in(struct fsi_master_gpio *master, struct fsi_gpio_msg *msg, + uint8_t num_bits) +{ + uint8_t bit, in_bit; + + set_sda_input(master); + + for (bit = 0; bit < num_bits; bit++) { + clock_toggle(master, 1); + in_bit = sda_in(master); + msg->msg <<= 1; + msg->msg |= ~in_bit & 0x1; /* Data is active low */ + } + msg->bits += num_bits; + + trace_fsi_master_gpio_in(master, num_bits, msg->msg); +} + +static void serial_out(struct fsi_master_gpio *master, + const struct fsi_gpio_msg *cmd) +{ + uint8_t bit; + uint64_t msg = ~cmd->msg; /* Data is active low */ + uint64_t sda_mask = 0x1ULL << (cmd->bits - 1); + uint64_t last_bit = ~0; + int next_bit; + + trace_fsi_master_gpio_out(master, cmd->bits, cmd->msg); + + if (!cmd->bits) { + dev_warn(master->dev, "trying to output 0 bits\n"); + return; + } + set_sda_output(master, 0); + + /* Send the start bit */ + sda_out(master, 0); + clock_toggle(master, 1); + + /* Send the message */ + for (bit = 0; bit < cmd->bits; bit++) { + next_bit = (msg & sda_mask) >> (cmd->bits - 1); + if (last_bit ^ next_bit) { + sda_out(master, next_bit); + last_bit = next_bit; + } + clock_toggle(master, 1); + msg <<= 1; + } +} + +static void msg_push_bits(struct fsi_gpio_msg *msg, uint64_t data, int bits) +{ + msg->msg <<= bits; + msg->msg |= data & ((1ull << bits) - 1); + msg->bits += bits; +} + +static void msg_push_crc(struct fsi_gpio_msg *msg) +{ + uint8_t crc; + int top; + + top = msg->bits & 0x3; + + /* start bit, and any non-aligned top bits */ + crc = crc4(0, 1 << top | msg->msg >> (msg->bits - top), top + 1); + + /* aligned bits */ + crc = crc4(crc, msg->msg, msg->bits - top); + + msg_push_bits(msg, crc, 4); +} + +/* + * Encode an Absolute Address command + */ +static void build_abs_ar_command(struct fsi_gpio_msg *cmd, + uint8_t id, uint32_t addr, size_t size, const void *data) +{ + bool write = !!data; + uint8_t ds; + int i; + + cmd->bits = 0; + cmd->msg = 0; + + msg_push_bits(cmd, id, 2); + msg_push_bits(cmd, FSI_GPIO_CMD_ABS_AR, 3); + msg_push_bits(cmd, write ? 0 : 1, 1); + + /* + * The read/write size is encoded in the lower bits of the address + * (as it must be naturally-aligned), and the following ds bit. + * + * size addr:1 addr:0 ds + * 1 x x 0 + * 2 x 0 1 + * 4 0 1 1 + * + */ + ds = size > 1 ? 1 : 0; + addr &= ~(size - 1); + if (size == 4) + addr |= 1; + + msg_push_bits(cmd, addr & ((1 << 21) - 1), 21); + msg_push_bits(cmd, ds, 1); + for (i = 0; write && i < size; i++) + msg_push_bits(cmd, ((uint8_t *)data)[i], 8); + + msg_push_crc(cmd); +} + +static void build_dpoll_command(struct fsi_gpio_msg *cmd, uint8_t slave_id) +{ + cmd->bits = 0; + cmd->msg = 0; + + msg_push_bits(cmd, slave_id, 2); + msg_push_bits(cmd, FSI_GPIO_CMD_DPOLL, 3); + msg_push_crc(cmd); +} + +static void echo_delay(struct fsi_master_gpio *master) +{ + set_sda_output(master, 1); + clock_toggle(master, FSI_ECHO_DELAY_CLOCKS); +} + +static void build_term_command(struct fsi_gpio_msg *cmd, uint8_t slave_id) +{ + cmd->bits = 0; + cmd->msg = 0; + + msg_push_bits(cmd, slave_id, 2); + msg_push_bits(cmd, FSI_GPIO_CMD_TERM, 6); + msg_push_crc(cmd); +} + +/* + * Store information on master errors so handler can detect and clean + * up the bus + */ +static void fsi_master_gpio_error(struct fsi_master_gpio *master, int error) +{ + +} + +static int read_one_response(struct fsi_master_gpio *master, + uint8_t data_size, struct fsi_gpio_msg *msgp, uint8_t *tagp) +{ + struct fsi_gpio_msg msg; + uint8_t id, tag; + uint32_t crc; + int i; + + /* wait for the start bit */ + for (i = 0; i < FSI_GPIO_MTOE_COUNT; i++) { + msg.bits = 0; + msg.msg = 0; + serial_in(master, &msg, 1); + if (msg.msg) + break; + } + if (i == FSI_GPIO_MTOE_COUNT) { + dev_dbg(master->dev, + "Master time out waiting for response\n"); + fsi_master_gpio_error(master, FSI_GPIO_MTOE); + return -EIO; + } + + msg.bits = 0; + msg.msg = 0; + + /* Read slave ID & response tag */ + serial_in(master, &msg, 4); + + id = (msg.msg >> FSI_GPIO_MSG_RESPID_SIZE) & 0x3; + tag = msg.msg & 0x3; + + /* If we have an ACK and we're expecting data, clock the data in too */ + if (tag == FSI_GPIO_RESP_ACK && data_size) + serial_in(master, &msg, data_size * 8); + + /* read CRC */ + serial_in(master, &msg, FSI_GPIO_CRC_SIZE); + + /* we have a whole message now; check CRC */ + crc = crc4(0, 1, 1); + crc = crc4(crc, msg.msg, msg.bits); + if (crc) { + dev_dbg(master->dev, "ERR response CRC\n"); + fsi_master_gpio_error(master, FSI_GPIO_CRC_INVAL); + return -EIO; + } + + if (msgp) + *msgp = msg; + if (tagp) + *tagp = tag; + + return 0; +} + +static int issue_term(struct fsi_master_gpio *master, uint8_t slave) +{ + struct fsi_gpio_msg cmd; + uint8_t tag; + int rc; + + build_term_command(&cmd, slave); + serial_out(master, &cmd); + echo_delay(master); + + rc = read_one_response(master, 0, NULL, &tag); + if (rc < 0) { + dev_err(master->dev, + "TERM failed; lost communication with slave\n"); + return -EIO; + } else if (tag != FSI_GPIO_RESP_ACK) { + dev_err(master->dev, "TERM failed; response %d\n", tag); + return -EIO; + } + + return 0; +} + +static int poll_for_response(struct fsi_master_gpio *master, + uint8_t slave, uint8_t size, void *data) +{ + struct fsi_gpio_msg response, cmd; + int busy_count = 0, rc, i; + uint8_t tag; + uint8_t *data_byte = data; + +retry: + rc = read_one_response(master, size, &response, &tag); + if (rc) + return rc; + + switch (tag) { + case FSI_GPIO_RESP_ACK: + if (size && data) { + uint64_t val = response.msg; + /* clear crc & mask */ + val >>= 4; + val &= (1ull << (size * 8)) - 1; + + for (i = 0; i < size; i++) { + data_byte[size-i-1] = val; + val >>= 8; + } + } + break; + case FSI_GPIO_RESP_BUSY: + /* + * Its necessary to clock slave before issuing + * d-poll, not indicated in the hardware protocol + * spec. < 20 clocks causes slave to hang, 21 ok. + */ + clock_zeros(master, FSI_GPIO_DPOLL_CLOCKS); + if (busy_count++ < FSI_GPIO_MAX_BUSY) { + build_dpoll_command(&cmd, slave); + serial_out(master, &cmd); + echo_delay(master); + goto retry; + } + dev_warn(master->dev, + "ERR slave is stuck in busy state, issuing TERM\n"); + issue_term(master, slave); + rc = -EIO; + break; + + case FSI_GPIO_RESP_ERRA: + case FSI_GPIO_RESP_ERRC: + dev_dbg(master->dev, "ERR%c received: 0x%x\n", + tag == FSI_GPIO_RESP_ERRA ? 'A' : 'C', + (int)response.msg); + fsi_master_gpio_error(master, response.msg); + rc = -EIO; + break; + } + + /* Clock the slave enough to be ready for next operation */ + clock_zeros(master, FSI_GPIO_PRIME_SLAVE_CLOCKS); + return rc; +} + +static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave, + struct fsi_gpio_msg *cmd, size_t resp_len, void *resp) +{ + unsigned long flags; + int rc; + + spin_lock_irqsave(&master->cmd_lock, flags); + serial_out(master, cmd); + echo_delay(master); + rc = poll_for_response(master, slave, resp_len, resp); + spin_unlock_irqrestore(&master->cmd_lock, flags); + + return rc; +} + +static int fsi_master_gpio_read(struct fsi_master *_master, int link, + uint8_t id, uint32_t addr, void *val, size_t size) +{ + struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + struct fsi_gpio_msg cmd; + + if (link != 0) + return -ENODEV; + + build_abs_ar_command(&cmd, id, addr, size, NULL); + return fsi_master_gpio_xfer(master, id, &cmd, size, val); +} + +static int fsi_master_gpio_write(struct fsi_master *_master, int link, + uint8_t id, uint32_t addr, const void *val, size_t size) +{ + struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + struct fsi_gpio_msg cmd; + + if (link != 0) + return -ENODEV; + + build_abs_ar_command(&cmd, id, addr, size, val); + return fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); +} + +static int fsi_master_gpio_term(struct fsi_master *_master, + int link, uint8_t id) +{ + struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + struct fsi_gpio_msg cmd; + + if (link != 0) + return -ENODEV; + + build_term_command(&cmd, id); + return fsi_master_gpio_xfer(master, id, &cmd, 0, NULL); +} + +static int fsi_master_gpio_break(struct fsi_master *_master, int link) +{ + struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + + if (link != 0) + return -ENODEV; + + trace_fsi_master_gpio_break(master); + + set_sda_output(master, 1); + sda_out(master, 1); + clock_toggle(master, FSI_PRE_BREAK_CLOCKS); + sda_out(master, 0); + clock_toggle(master, FSI_BREAK_CLOCKS); + echo_delay(master); + sda_out(master, 1); + clock_toggle(master, FSI_POST_BREAK_CLOCKS); + + /* Wait for logic reset to take effect */ + udelay(200); + + return 0; +} + +static void fsi_master_gpio_init(struct fsi_master_gpio *master) +{ + gpiod_direction_output(master->gpio_mux, 1); + gpiod_direction_output(master->gpio_trans, 1); + gpiod_direction_output(master->gpio_enable, 1); + gpiod_direction_output(master->gpio_clk, 1); + gpiod_direction_output(master->gpio_data, 1); + + /* todo: evaluate if clocks can be reduced */ + clock_zeros(master, FSI_INIT_CLOCKS); +} + +static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link) +{ + struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + + if (link != 0) + return -ENODEV; + gpiod_set_value(master->gpio_enable, 1); + + return 0; +} + +static int fsi_master_gpio_probe(struct platform_device *pdev) +{ + struct fsi_master_gpio *master; + struct gpio_desc *gpio; + + master = devm_kzalloc(&pdev->dev, sizeof(*master), GFP_KERNEL); + if (!master) + return -ENOMEM; + + master->dev = &pdev->dev; + master->master.dev.parent = master->dev; + + gpio = devm_gpiod_get(&pdev->dev, "clock", 0); + if (IS_ERR(gpio)) { + dev_err(&pdev->dev, "failed to get clock gpio\n"); + return PTR_ERR(gpio); + } + master->gpio_clk = gpio; + + gpio = devm_gpiod_get(&pdev->dev, "data", 0); + if (IS_ERR(gpio)) { + dev_err(&pdev->dev, "failed to get data gpio\n"); + return PTR_ERR(gpio); + } + master->gpio_data = gpio; + + /* Optional GPIOs */ + gpio = devm_gpiod_get_optional(&pdev->dev, "trans", 0); + if (IS_ERR(gpio)) { + dev_err(&pdev->dev, "failed to get trans gpio\n"); + return PTR_ERR(gpio); + } + master->gpio_trans = gpio; + + gpio = devm_gpiod_get_optional(&pdev->dev, "enable", 0); + if (IS_ERR(gpio)) { + dev_err(&pdev->dev, "failed to get enable gpio\n"); + return PTR_ERR(gpio); + } + master->gpio_enable = gpio; + + gpio = devm_gpiod_get_optional(&pdev->dev, "mux", 0); + if (IS_ERR(gpio)) { + dev_err(&pdev->dev, "failed to get mux gpio\n"); + return PTR_ERR(gpio); + } + master->gpio_mux = gpio; + + master->master.n_links = 1; + master->master.flags = FSI_MASTER_FLAG_SWCLOCK; + master->master.read = fsi_master_gpio_read; + master->master.write = fsi_master_gpio_write; + master->master.term = fsi_master_gpio_term; + master->master.send_break = fsi_master_gpio_break; + master->master.link_enable = fsi_master_gpio_link_enable; + platform_set_drvdata(pdev, master); + spin_lock_init(&master->cmd_lock); + + fsi_master_gpio_init(master); + + return fsi_master_register(&master->master); +} + + +static int fsi_master_gpio_remove(struct platform_device *pdev) +{ + struct fsi_master_gpio *master = platform_get_drvdata(pdev); + + devm_gpiod_put(&pdev->dev, master->gpio_clk); + devm_gpiod_put(&pdev->dev, master->gpio_data); + if (master->gpio_trans) + devm_gpiod_put(&pdev->dev, master->gpio_trans); + if (master->gpio_enable) + devm_gpiod_put(&pdev->dev, master->gpio_enable); + if (master->gpio_mux) + devm_gpiod_put(&pdev->dev, master->gpio_mux); + fsi_master_unregister(&master->master); + + return 0; +} + +static const struct of_device_id fsi_master_gpio_match[] = { + { .compatible = "fsi-master-gpio" }, + { }, +}; + +static struct platform_driver fsi_master_gpio_driver = { + .driver = { + .name = "fsi-master-gpio", + .of_match_table = fsi_master_gpio_match, + }, + .probe = fsi_master_gpio_probe, + .remove = fsi_master_gpio_remove, +}; + +module_platform_driver(fsi_master_gpio_driver); +MODULE_LICENSE("GPL"); diff --git a/drivers/fsi/fsi-master-hub.c b/drivers/fsi/fsi-master-hub.c new file mode 100644 index 000000000000..133b9bff1d65 --- /dev/null +++ b/drivers/fsi/fsi-master-hub.c @@ -0,0 +1,327 @@ +/* + * FSI hub master driver + * + * Copyright (C) IBM Corporation 2016 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/delay.h> +#include <linux/fsi.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include "fsi-master.h" + +/* Control Registers */ +#define FSI_MMODE 0x0 /* R/W: mode */ +#define FSI_MDLYR 0x4 /* R/W: delay */ +#define FSI_MCRSP 0x8 /* R/W: clock rate */ +#define FSI_MENP0 0x10 /* R/W: enable */ +#define FSI_MLEVP0 0x18 /* R: plug detect */ +#define FSI_MSENP0 0x18 /* S: Set enable */ +#define FSI_MCENP0 0x20 /* C: Clear enable */ +#define FSI_MAEB 0x70 /* R: Error address */ +#define FSI_MVER 0x74 /* R: master version/type */ +#define FSI_MRESP0 0xd0 /* W: Port reset */ +#define FSI_MESRB0 0x1d0 /* R: Master error status */ +#define FSI_MRESB0 0x1d0 /* W: Reset bridge */ +#define FSI_MECTRL 0x2e0 /* W: Error control */ + +/* MMODE: Mode control */ +#define FSI_MMODE_EIP 0x80000000 /* Enable interrupt polling */ +#define FSI_MMODE_ECRC 0x40000000 /* Enable error recovery */ +#define FSI_MMODE_EPC 0x10000000 /* Enable parity checking */ +#define FSI_MMODE_P8_TO_LSB 0x00000010 /* Timeout value LSB */ + /* MSB=1, LSB=0 is 0.8 ms */ + /* MSB=0, LSB=1 is 0.9 ms */ +#define FSI_MMODE_CRS0SHFT 18 /* Clk rate selection 0 shift */ +#define FSI_MMODE_CRS0MASK 0x3ff /* Clk rate selection 0 mask */ +#define FSI_MMODE_CRS1SHFT 8 /* Clk rate selection 1 shift */ +#define FSI_MMODE_CRS1MASK 0x3ff /* Clk rate selection 1 mask */ + +/* MRESB: Reset brindge */ +#define FSI_MRESB_RST_GEN 0x80000000 /* General reset */ +#define FSI_MRESB_RST_ERR 0x40000000 /* Error Reset */ + +/* MRESB: Reset port */ +#define FSI_MRESP_RST_ALL_MASTER 0x20000000 /* Reset all FSI masters */ +#define FSI_MRESP_RST_ALL_LINK 0x10000000 /* Reset all FSI port contr. */ +#define FSI_MRESP_RST_MCR 0x08000000 /* Reset FSI master reg. */ +#define FSI_MRESP_RST_PYE 0x04000000 /* Reset FSI parity error */ +#define FSI_MRESP_RST_ALL 0xfc000000 /* Reset any error */ + +/* MECTRL: Error control */ +#define FSI_MECTRL_EOAE 0x8000 /* Enable machine check when */ + /* master 0 in error */ +#define FSI_MECTRL_P8_AUTO_TERM 0x4000 /* Auto terminate */ + +#define FSI_ENGID_HUB_MASTER 0x1c +#define FSI_HUB_LINK_OFFSET 0x80000 +#define FSI_HUB_LINK_SIZE 0x80000 +#define FSI_HUB_MASTER_MAX_LINKS 8 + +#define FSI_LINK_ENABLE_SETUP_TIME 10 /* in mS */ + +/* + * FSI hub master support + * + * A hub master increases the number of potential target devices that the + * primary FSI master can access. For each link a primary master supports, + * each of those links can in turn be chained to a hub master with multiple + * links of its own. + * + * The hub is controlled by a set of control registers exposed as a regular fsi + * device (the hub->upstream device), and provides access to the downstream FSI + * bus as through an address range on the slave itself (->addr and ->size). + * + * [This differs from "cascaded" masters, which expose the entire downstream + * bus entirely through the fsi device address range, and so have a smaller + * accessible address space.] + */ +struct fsi_master_hub { + struct fsi_master master; + struct fsi_device *upstream; + uint32_t addr, size; /* slave-relative addr of */ + /* master address space */ +}; + +#define to_fsi_master_hub(m) container_of(m, struct fsi_master_hub, master) + +static int hub_master_read(struct fsi_master *master, int link, + uint8_t id, uint32_t addr, void *val, size_t size) +{ + struct fsi_master_hub *hub = to_fsi_master_hub(master); + + if (id != 0) + return -EINVAL; + + addr += hub->addr + (link * FSI_HUB_LINK_SIZE); + return fsi_slave_read(hub->upstream->slave, addr, val, size); +} + +static int hub_master_write(struct fsi_master *master, int link, + uint8_t id, uint32_t addr, const void *val, size_t size) +{ + struct fsi_master_hub *hub = to_fsi_master_hub(master); + + if (id != 0) + return -EINVAL; + + addr += hub->addr + (link * FSI_HUB_LINK_SIZE); + return fsi_slave_write(hub->upstream->slave, addr, val, size); +} + +static int hub_master_break(struct fsi_master *master, int link) +{ + uint32_t addr, cmd; + + addr = 0x4; + cmd = cpu_to_be32(0xc0de0000); + + return hub_master_write(master, link, 0, addr, &cmd, sizeof(cmd)); +} + +static int hub_master_link_enable(struct fsi_master *master, int link) +{ + struct fsi_master_hub *hub = to_fsi_master_hub(master); + int idx, bit; + __be32 reg; + int rc; + + idx = link / 32; + bit = link % 32; + + reg = cpu_to_be32(0x80000000 >> bit); + + rc = fsi_device_write(hub->upstream, FSI_MSENP0 + (4 * idx), ®, 4); + + mdelay(FSI_LINK_ENABLE_SETUP_TIME); + + fsi_device_read(hub->upstream, FSI_MENP0 + (4 * idx), ®, 4); + + return rc; +} + +static void hub_master_release(struct device *dev) +{ + struct fsi_master_hub *hub = to_fsi_master_hub(dev_to_fsi_master(dev)); + + kfree(hub); +} + +/* mmode encoders */ +static inline u32 fsi_mmode_crs0(u32 x) +{ + return (x & FSI_MMODE_CRS0MASK) << FSI_MMODE_CRS0SHFT; +} + +static inline u32 fsi_mmode_crs1(u32 x) +{ + return (x & FSI_MMODE_CRS1MASK) << FSI_MMODE_CRS1SHFT; +} + +static int hub_master_init(struct fsi_master_hub *hub) +{ + struct fsi_device *dev = hub->upstream; + __be32 reg; + int rc; + + reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK + | FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE); + rc = fsi_device_write(dev, FSI_MRESP0, ®, sizeof(reg)); + if (rc) + return rc; + + /* Initialize the MFSI (hub master) engine */ + reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK + | FSI_MRESP_RST_MCR | FSI_MRESP_RST_PYE); + rc = fsi_device_write(dev, FSI_MRESP0, ®, sizeof(reg)); + if (rc) + return rc; + + reg = cpu_to_be32(FSI_MECTRL_EOAE | FSI_MECTRL_P8_AUTO_TERM); + rc = fsi_device_write(dev, FSI_MECTRL, ®, sizeof(reg)); + if (rc) + return rc; + + reg = cpu_to_be32(FSI_MMODE_EIP | FSI_MMODE_ECRC | FSI_MMODE_EPC + | fsi_mmode_crs0(1) | fsi_mmode_crs1(1) + | FSI_MMODE_P8_TO_LSB); + rc = fsi_device_write(dev, FSI_MMODE, ®, sizeof(reg)); + if (rc) + return rc; + + reg = cpu_to_be32(0xffff0000); + rc = fsi_device_write(dev, FSI_MDLYR, ®, sizeof(reg)); + if (rc) + return rc; + + reg = ~0; + rc = fsi_device_write(dev, FSI_MSENP0, ®, sizeof(reg)); + if (rc) + return rc; + + /* Leave enabled long enough for master logic to set up */ + mdelay(FSI_LINK_ENABLE_SETUP_TIME); + + rc = fsi_device_write(dev, FSI_MCENP0, ®, sizeof(reg)); + if (rc) + return rc; + + rc = fsi_device_read(dev, FSI_MAEB, ®, sizeof(reg)); + if (rc) + return rc; + + reg = cpu_to_be32(FSI_MRESP_RST_ALL_MASTER | FSI_MRESP_RST_ALL_LINK); + rc = fsi_device_write(dev, FSI_MRESP0, ®, sizeof(reg)); + if (rc) + return rc; + + rc = fsi_device_read(dev, FSI_MLEVP0, ®, sizeof(reg)); + if (rc) + return rc; + + /* Reset the master bridge */ + reg = cpu_to_be32(FSI_MRESB_RST_GEN); + rc = fsi_device_write(dev, FSI_MRESB0, ®, sizeof(reg)); + if (rc) + return rc; + + reg = cpu_to_be32(FSI_MRESB_RST_ERR); + return fsi_device_write(dev, FSI_MRESB0, ®, sizeof(reg)); +} + +static int hub_master_probe(struct device *dev) +{ + struct fsi_device *fsi_dev = to_fsi_dev(dev); + struct fsi_master_hub *hub; + uint32_t reg, links; + __be32 __reg; + int rc; + + rc = fsi_device_read(fsi_dev, FSI_MVER, &__reg, sizeof(__reg)); + if (rc) + return rc; + + reg = be32_to_cpu(__reg); + links = (reg >> 8) & 0xff; + dev_info(dev, "hub version %08x (%d links)\n", reg, links); + + rc = fsi_slave_claim_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET, + FSI_HUB_LINK_SIZE * links); + if (rc) { + dev_err(dev, "can't claim slave address range for links"); + return rc; + } + + hub = kzalloc(sizeof(*hub), GFP_KERNEL); + if (!hub) { + rc = -ENOMEM; + goto err_release; + } + + hub->addr = FSI_HUB_LINK_OFFSET; + hub->size = FSI_HUB_LINK_SIZE * links; + hub->upstream = fsi_dev; + + hub->master.dev.parent = dev; + hub->master.dev.release = hub_master_release; + + hub->master.n_links = links; + hub->master.read = hub_master_read; + hub->master.write = hub_master_write; + hub->master.send_break = hub_master_break; + hub->master.link_enable = hub_master_link_enable; + + dev_set_drvdata(dev, hub); + + hub_master_init(hub); + + rc = fsi_master_register(&hub->master); + if (!rc) + return 0; + + kfree(hub); +err_release: + fsi_slave_release_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET, + FSI_HUB_LINK_SIZE * links); + return rc; +} + +static int hub_master_remove(struct device *dev) +{ + struct fsi_master_hub *hub = dev_get_drvdata(dev); + + fsi_master_unregister(&hub->master); + fsi_slave_release_range(hub->upstream->slave, hub->addr, hub->size); + return 0; +} + +static struct fsi_device_id hub_master_ids[] = { + { + .engine_type = FSI_ENGID_HUB_MASTER, + .version = FSI_VERSION_ANY, + }, + { 0 } +}; + +static struct fsi_driver hub_master_driver = { + .id_table = hub_master_ids, + .drv = { + .name = "fsi-master-hub", + .bus = &fsi_bus_type, + .probe = hub_master_probe, + .remove = hub_master_remove, + } +}; + +module_fsi_driver(hub_master_driver); +MODULE_LICENSE("GPL"); diff --git a/drivers/fsi/fsi-master.h b/drivers/fsi/fsi-master.h new file mode 100644 index 000000000000..12f7b119567d --- /dev/null +++ b/drivers/fsi/fsi-master.h @@ -0,0 +1,43 @@ +/* + * FSI master definitions. These comprise the core <--> master interface, + * to allow the core to interact with the (hardware-specific) masters. + * + * Copyright (C) IBM Corporation 2016 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef DRIVERS_FSI_MASTER_H +#define DRIVERS_FSI_MASTER_H + +#include <linux/device.h> + +#define FSI_MASTER_FLAG_SWCLOCK 0x1 + +struct fsi_master { + struct device dev; + int idx; + int n_links; + int flags; + int (*read)(struct fsi_master *, int link, uint8_t id, + uint32_t addr, void *val, size_t size); + int (*write)(struct fsi_master *, int link, uint8_t id, + uint32_t addr, const void *val, size_t size); + int (*term)(struct fsi_master *, int link, uint8_t id); + int (*send_break)(struct fsi_master *, int link); + int (*link_enable)(struct fsi_master *, int link); +}; + +#define dev_to_fsi_master(d) container_of(d, struct fsi_master, dev) + +extern int fsi_master_register(struct fsi_master *master); +extern void fsi_master_unregister(struct fsi_master *master); + +#endif /* DRIVERS_FSI_MASTER_H */ diff --git a/drivers/fsi/fsi-scom.c b/drivers/fsi/fsi-scom.c new file mode 100644 index 000000000000..98d062fd353e --- /dev/null +++ b/drivers/fsi/fsi-scom.c @@ -0,0 +1,263 @@ +/* + * SCOM FSI Client device driver + * + * Copyright (C) IBM Corporation 2016 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERGCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/fsi.h> +#include <linux/module.h> +#include <linux/cdev.h> +#include <linux/delay.h> +#include <linux/fs.h> +#include <linux/uaccess.h> +#include <linux/slab.h> +#include <linux/miscdevice.h> +#include <linux/list.h> +#include <linux/idr.h> + +#define FSI_ENGID_SCOM 0x5 + +#define SCOM_FSI2PIB_DELAY 50 + +/* SCOM engine register set */ +#define SCOM_DATA0_REG 0x00 +#define SCOM_DATA1_REG 0x04 +#define SCOM_CMD_REG 0x08 +#define SCOM_RESET_REG 0x1C + +#define SCOM_RESET_CMD 0x80000000 +#define SCOM_WRITE_CMD 0x80000000 + +struct scom_device { + struct list_head link; + struct fsi_device *fsi_dev; + struct miscdevice mdev; + char name[32]; + int idx; +}; + +#define to_scom_dev(x) container_of((x), struct scom_device, mdev) + +static struct list_head scom_devices; + +static DEFINE_IDA(scom_ida); + +static int put_scom(struct scom_device *scom_dev, uint64_t value, + uint32_t addr) +{ + int rc; + uint32_t data; + + data = cpu_to_be32(SCOM_RESET_CMD); + rc = fsi_device_write(scom_dev->fsi_dev, SCOM_RESET_REG, &data, + sizeof(uint32_t)); + if (rc) + return rc; + + data = cpu_to_be32((value >> 32) & 0xffffffff); + rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA0_REG, &data, + sizeof(uint32_t)); + if (rc) + return rc; + + data = cpu_to_be32(value & 0xffffffff); + rc = fsi_device_write(scom_dev->fsi_dev, SCOM_DATA1_REG, &data, + sizeof(uint32_t)); + if (rc) + return rc; + + data = cpu_to_be32(SCOM_WRITE_CMD | addr); + return fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data, + sizeof(uint32_t)); +} + +static int get_scom(struct scom_device *scom_dev, uint64_t *value, + uint32_t addr) +{ + uint32_t result, data; + int rc; + + *value = 0ULL; + data = cpu_to_be32(addr); + rc = fsi_device_write(scom_dev->fsi_dev, SCOM_CMD_REG, &data, + sizeof(uint32_t)); + if (rc) + return rc; + + rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA0_REG, &result, + sizeof(uint32_t)); + if (rc) + return rc; + + *value |= (uint64_t)cpu_to_be32(result) << 32; + rc = fsi_device_read(scom_dev->fsi_dev, SCOM_DATA1_REG, &result, + sizeof(uint32_t)); + if (rc) + return rc; + + *value |= cpu_to_be32(result); + + return 0; +} + +static ssize_t scom_read(struct file *filep, char __user *buf, size_t len, + loff_t *offset) +{ + int rc; + struct miscdevice *mdev = + (struct miscdevice *)filep->private_data; + struct scom_device *scom = to_scom_dev(mdev); + struct device *dev = &scom->fsi_dev->dev; + uint64_t val; + + if (len != sizeof(uint64_t)) + return -EINVAL; + + rc = get_scom(scom, &val, *offset); + if (rc) { + dev_dbg(dev, "get_scom fail:%d\n", rc); + return rc; + } + + rc = copy_to_user(buf, &val, len); + if (rc) + dev_dbg(dev, "copy to user failed:%d\n", rc); + + return rc ? rc : len; +} + +static ssize_t scom_write(struct file *filep, const char __user *buf, + size_t len, loff_t *offset) +{ + int rc; + struct miscdevice *mdev = filep->private_data; + struct scom_device *scom = to_scom_dev(mdev); + struct device *dev = &scom->fsi_dev->dev; + uint64_t val; + + if (len != sizeof(uint64_t)) + return -EINVAL; + + rc = copy_from_user(&val, buf, len); + if (rc) { + dev_dbg(dev, "copy from user failed:%d\n", rc); + return -EINVAL; + } + + rc = put_scom(scom, val, *offset); + if (rc) { + dev_dbg(dev, "put_scom failed with:%d\n", rc); + return rc; + } + + return len; +} + +static loff_t scom_llseek(struct file *file, loff_t offset, int whence) +{ + switch (whence) { + case SEEK_CUR: + break; + case SEEK_SET: + file->f_pos = offset; + break; + default: + return -EINVAL; + } + + return offset; +} + +static const struct file_operations scom_fops = { + .owner = THIS_MODULE, + .llseek = scom_llseek, + .read = scom_read, + .write = scom_write, +}; + +static int scom_probe(struct device *dev) +{ + struct fsi_device *fsi_dev = to_fsi_dev(dev); + struct scom_device *scom; + + scom = devm_kzalloc(dev, sizeof(*scom), GFP_KERNEL); + if (!scom) + return -ENOMEM; + + scom->idx = ida_simple_get(&scom_ida, 1, INT_MAX, GFP_KERNEL); + snprintf(scom->name, sizeof(scom->name), "scom%d", scom->idx); + scom->fsi_dev = fsi_dev; + scom->mdev.minor = MISC_DYNAMIC_MINOR; + scom->mdev.fops = &scom_fops; + scom->mdev.name = scom->name; + scom->mdev.parent = dev; + list_add(&scom->link, &scom_devices); + + return misc_register(&scom->mdev); +} + +static int scom_remove(struct device *dev) +{ + struct scom_device *scom, *scom_tmp; + struct fsi_device *fsi_dev = to_fsi_dev(dev); + + list_for_each_entry_safe(scom, scom_tmp, &scom_devices, link) { + if (scom->fsi_dev == fsi_dev) { + list_del(&scom->link); + ida_simple_remove(&scom_ida, scom->idx); + misc_deregister(&scom->mdev); + } + } + + return 0; +} + +static struct fsi_device_id scom_ids[] = { + { + .engine_type = FSI_ENGID_SCOM, + .version = FSI_VERSION_ANY, + }, + { 0 } +}; + +static struct fsi_driver scom_drv = { + .id_table = scom_ids, + .drv = { + .name = "scom", + .bus = &fsi_bus_type, + .probe = scom_probe, + .remove = scom_remove, + } +}; + +static int scom_init(void) +{ + INIT_LIST_HEAD(&scom_devices); + return fsi_driver_register(&scom_drv); +} + +static void scom_exit(void) +{ + struct list_head *pos; + struct scom_device *scom; + + list_for_each(pos, &scom_devices) { + scom = list_entry(pos, struct scom_device, link); + misc_deregister(&scom->mdev); + devm_kfree(&scom->fsi_dev->dev, scom); + } + fsi_driver_unregister(&scom_drv); +} + +module_init(scom_init); +module_exit(scom_exit); +MODULE_LICENSE("GPL"); |