diff options
Diffstat (limited to 'drivers/fsi')
| -rw-r--r-- | drivers/fsi/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/fsi/fsi-core.c | 129 | ||||
| -rw-r--r-- | drivers/fsi/fsi-master-gpio.c | 89 | ||||
| -rw-r--r-- | drivers/fsi/fsi-master-hub.c | 27 | ||||
| -rw-r--r-- | drivers/fsi/fsi-master.h | 17 |
5 files changed, 248 insertions, 15 deletions
diff --git a/drivers/fsi/Kconfig b/drivers/fsi/Kconfig index 513e35173aaa..a326ed663d3c 100644 --- a/drivers/fsi/Kconfig +++ b/drivers/fsi/Kconfig @@ -4,6 +4,7 @@ menuconfig FSI tristate "FSI support" + depends on OF select CRC4 ---help--- FSI - the FRU Support Interface - is a simple bus for low-level diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c index e318bf8c623c..4c03d6933646 100644 --- a/drivers/fsi/fsi-core.c +++ b/drivers/fsi/fsi-core.c @@ -18,6 +18,7 @@ #include <linux/fsi.h> #include <linux/idr.h> #include <linux/module.h> +#include <linux/of.h> #include <linux/slab.h> #include <linux/bitops.h> @@ -142,6 +143,7 @@ static void fsi_device_release(struct device *_device) { struct fsi_device *device = to_fsi_dev(_device); + of_node_put(device->dev.of_node); kfree(device); } @@ -205,7 +207,7 @@ static int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) if (rc) return rc; - dev_info(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", + dev_dbg(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", be32_to_cpu(stat), be32_to_cpu(irq)); /* clear interrupts */ @@ -334,6 +336,57 @@ extern void fsi_slave_release_range(struct fsi_slave *slave, } EXPORT_SYMBOL_GPL(fsi_slave_release_range); +static bool fsi_device_node_matches(struct device *dev, struct device_node *np, + uint32_t addr, uint32_t size) +{ + unsigned int len, na, ns; + const __be32 *prop; + uint32_t psize; + + na = of_n_addr_cells(np); + ns = of_n_size_cells(np); + + if (na != 1 || ns != 1) + return false; + + prop = of_get_property(np, "reg", &len); + if (!prop || len != 8) + return false; + + if (of_read_number(prop, 1) != addr) + return false; + + psize = of_read_number(prop + 1, 1); + if (psize != size) { + dev_warn(dev, + "node %s matches probed address, but not size (got 0x%x, expected 0x%x)", + of_node_full_name(np), psize, size); + } + + return true; +} + +/* Find a matching node for the slave engine at @address, using @size bytes + * of space. Returns NULL if not found, or a matching node with refcount + * already incremented. + */ +static struct device_node *fsi_device_find_of_node(struct fsi_device *dev) +{ + struct device_node *parent, *np; + + parent = dev_of_node(&dev->slave->dev); + if (!parent) + return NULL; + + for_each_child_of_node(parent, np) { + if (fsi_device_node_matches(&dev->dev, np, + dev->addr, dev->size)) + return np; + } + + return NULL; +} + static int fsi_slave_scan(struct fsi_slave *slave) { uint32_t engine_addr; @@ -402,6 +455,7 @@ static int fsi_slave_scan(struct fsi_slave *slave) dev_set_name(&dev->dev, "%02x:%02x:%02x:%02x", slave->master->idx, slave->link, slave->id, i - 2); + dev->dev.of_node = fsi_device_find_of_node(dev); rc = device_register(&dev->dev); if (rc) { @@ -558,9 +612,53 @@ static void fsi_slave_release(struct device *dev) { struct fsi_slave *slave = to_fsi_slave(dev); + of_node_put(dev->of_node); kfree(slave); } +static bool fsi_slave_node_matches(struct device_node *np, + int link, uint8_t id) +{ + unsigned int len, na, ns; + const __be32 *prop; + + na = of_n_addr_cells(np); + ns = of_n_size_cells(np); + + /* Ensure we have the correct format for addresses and sizes in + * reg properties + */ + if (na != 2 || ns != 0) + return false; + + prop = of_get_property(np, "reg", &len); + if (!prop || len != 8) + return false; + + return (of_read_number(prop, 1) == link) && + (of_read_number(prop + 1, 1) == id); +} + +/* Find a matching node for the slave at (link, id). Returns NULL if none + * found, or a matching node with refcount already incremented. + */ +static struct device_node *fsi_slave_find_of_node(struct fsi_master *master, + int link, uint8_t id) +{ + struct device_node *parent, *np; + + parent = dev_of_node(&master->dev); + if (!parent) + return NULL; + + for_each_child_of_node(parent, np) { + if (fsi_slave_node_matches(np, link, id)) + return np; + } + + return NULL; +} + static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) { uint32_t chip_id, llmode; @@ -589,7 +687,7 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) return -EIO; } - dev_info(&master->dev, "fsi: found chip %08x at %02x:%02x:%02x\n", + dev_dbg(&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); @@ -623,6 +721,7 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) slave->master = master; slave->dev.parent = &master->dev; + slave->dev.of_node = fsi_slave_find_of_node(master, link, id); slave->dev.release = fsi_slave_release; slave->link = link; slave->id = id; @@ -656,10 +755,13 @@ static int fsi_slave_init(struct fsi_master *master, int link, uint8_t id) /* 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)) + if (size == 4) { + if (addr & 0x3) + return -EINVAL; + } else if (size == 2) { + if (addr & 0x1) + return -EINVAL; + } else if (size != 1) return -EINVAL; return 0; @@ -762,14 +864,20 @@ static void fsi_master_unscan(struct fsi_master *master) device_for_each_child(&master->dev, NULL, fsi_master_remove_slave); } +int fsi_master_rescan(struct fsi_master *master) +{ + fsi_master_unscan(master); + return fsi_master_scan(master); +} +EXPORT_SYMBOL_GPL(fsi_master_rescan); + 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); + rc = fsi_master_rescan(master); if (rc < 0) return rc; @@ -793,6 +901,7 @@ static DEVICE_ATTR(break, 0200, NULL, master_break_store); int fsi_master_register(struct fsi_master *master) { int rc; + struct device_node *np; if (!master) return -EINVAL; @@ -820,7 +929,9 @@ int fsi_master_register(struct fsi_master *master) return rc; } - fsi_master_scan(master); + np = dev_of_node(&master->dev); + if (!of_property_read_bool(np, "no-scan-on-init")) + fsi_master_scan(master); return 0; } diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c index ae2618768508..3f487449a277 100644 --- a/drivers/fsi/fsi-master-gpio.c +++ b/drivers/fsi/fsi-master-gpio.c @@ -9,6 +9,7 @@ #include <linux/gpio/consumer.h> #include <linux/io.h> #include <linux/module.h> +#include <linux/of.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/spinlock.h> @@ -59,6 +60,7 @@ struct fsi_master_gpio { struct gpio_desc *gpio_trans; /* Voltage translator */ struct gpio_desc *gpio_enable; /* FSI enable */ struct gpio_desc *gpio_mux; /* Mux control */ + bool external_mode; }; #define CREATE_TRACE_POINTS @@ -411,6 +413,12 @@ static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave, int rc; spin_lock_irqsave(&master->cmd_lock, flags); + + if (master->external_mode) { + spin_unlock_irqrestore(&master->cmd_lock, flags); + return -EBUSY; + } + serial_out(master, cmd); echo_delay(master); rc = poll_for_response(master, slave, resp_len, resp); @@ -461,12 +469,18 @@ static int fsi_master_gpio_term(struct fsi_master *_master, static int fsi_master_gpio_break(struct fsi_master *_master, int link) { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + unsigned long flags; if (link != 0) return -ENODEV; trace_fsi_master_gpio_break(master); + spin_lock_irqsave(&master->cmd_lock, flags); + if (master->external_mode) { + spin_unlock_irqrestore(&master->cmd_lock, flags); + return -EBUSY; + } set_sda_output(master, 1); sda_out(master, 1); clock_toggle(master, FSI_PRE_BREAK_CLOCKS); @@ -475,6 +489,7 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) echo_delay(master); sda_out(master, 1); clock_toggle(master, FSI_POST_BREAK_CLOCKS); + spin_unlock_irqrestore(&master->cmd_lock, flags); /* Wait for logic reset to take effect */ udelay(200); @@ -494,21 +509,84 @@ static void fsi_master_gpio_init(struct fsi_master_gpio *master) clock_zeros(master, FSI_INIT_CLOCKS); } +static void fsi_master_gpio_init_external(struct fsi_master_gpio *master) +{ + gpiod_direction_output(master->gpio_mux, 0); + gpiod_direction_output(master->gpio_trans, 0); + gpiod_direction_output(master->gpio_enable, 1); + gpiod_direction_input(master->gpio_clk); + gpiod_direction_input(master->gpio_data); +} + static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link) { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + unsigned long flags; + int rc = -EBUSY; if (link != 0) return -ENODEV; - gpiod_set_value(master->gpio_enable, 1); - return 0; + spin_lock_irqsave(&master->cmd_lock, flags); + if (!master->external_mode) { + gpiod_set_value(master->gpio_enable, 1); + rc = 0; + } + spin_unlock_irqrestore(&master->cmd_lock, flags); + + return rc; +} + +static ssize_t external_mode_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct fsi_master_gpio *master = dev_get_drvdata(dev); + + return snprintf(buf, PAGE_SIZE - 1, "%u\n", + master->external_mode ? 1 : 0); } +static ssize_t external_mode_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct fsi_master_gpio *master = dev_get_drvdata(dev); + unsigned long flags, val; + bool external_mode; + int err; + + err = kstrtoul(buf, 0, &val); + if (err) + return err; + + external_mode = !!val; + + spin_lock_irqsave(&master->cmd_lock, flags); + + if (external_mode == master->external_mode) { + spin_unlock_irqrestore(&master->cmd_lock, flags); + return count; + } + + master->external_mode = external_mode; + if (master->external_mode) + fsi_master_gpio_init_external(master); + else + fsi_master_gpio_init(master); + spin_unlock_irqrestore(&master->cmd_lock, flags); + + fsi_master_rescan(&master->master); + + return count; +} + +static DEVICE_ATTR(external_mode, 0664, + external_mode_show, external_mode_store); + static int fsi_master_gpio_probe(struct platform_device *pdev) { struct fsi_master_gpio *master; struct gpio_desc *gpio; + int rc; master = devm_kzalloc(&pdev->dev, sizeof(*master), GFP_KERNEL); if (!master) @@ -516,6 +594,7 @@ static int fsi_master_gpio_probe(struct platform_device *pdev) master->dev = &pdev->dev; master->master.dev.parent = master->dev; + master->master.dev.of_node = of_node_get(dev_of_node(master->dev)); gpio = devm_gpiod_get(&pdev->dev, "clock", 0); if (IS_ERR(gpio)) { @@ -565,6 +644,10 @@ static int fsi_master_gpio_probe(struct platform_device *pdev) fsi_master_gpio_init(master); + rc = device_create_file(&pdev->dev, &dev_attr_external_mode); + if (rc) + return rc; + return fsi_master_register(&master->master); } @@ -583,6 +666,8 @@ static int fsi_master_gpio_remove(struct platform_device *pdev) devm_gpiod_put(&pdev->dev, master->gpio_mux); fsi_master_unregister(&master->master); + of_node_put(master->master.dev.of_node); + return 0; } diff --git a/drivers/fsi/fsi-master-hub.c b/drivers/fsi/fsi-master-hub.c index 133b9bff1d65..5885fc4a1ef0 100644 --- a/drivers/fsi/fsi-master-hub.c +++ b/drivers/fsi/fsi-master-hub.c @@ -16,6 +16,7 @@ #include <linux/delay.h> #include <linux/fsi.h> #include <linux/module.h> +#include <linux/of.h> #include <linux/slab.h> #include "fsi-master.h" @@ -253,7 +254,7 @@ static int hub_master_probe(struct device *dev) reg = be32_to_cpu(__reg); links = (reg >> 8) & 0xff; - dev_info(dev, "hub version %08x (%d links)\n", reg, links); + dev_dbg(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); @@ -274,6 +275,7 @@ static int hub_master_probe(struct device *dev) hub->master.dev.parent = dev; hub->master.dev.release = hub_master_release; + hub->master.dev.of_node = of_node_get(dev_of_node(dev)); hub->master.n_links = links; hub->master.read = hub_master_read; @@ -286,10 +288,19 @@ static int hub_master_probe(struct device *dev) hub_master_init(hub); rc = fsi_master_register(&hub->master); - if (!rc) - return 0; + if (rc) + goto err_release; + + /* At this point, fsi_master_register performs the device_initialize(), + * and holds the sole reference on master.dev. This means the device + * will be freed (via ->release) during any subsequent call to + * fsi_master_unregister. We add our own reference to it here, so we + * can perform cleanup (in _remove()) without it being freed before + * we're ready. + */ + get_device(&hub->master.dev); + return 0; - kfree(hub); err_release: fsi_slave_release_range(fsi_dev->slave, FSI_HUB_LINK_OFFSET, FSI_HUB_LINK_SIZE * links); @@ -302,6 +313,14 @@ static int hub_master_remove(struct device *dev) fsi_master_unregister(&hub->master); fsi_slave_release_range(hub->upstream->slave, hub->addr, hub->size); + of_node_put(hub->master.dev.of_node); + + /* + * master.dev will likely be ->release()ed after this, which free()s + * the hub + */ + put_device(&hub->master.dev); + return 0; } diff --git a/drivers/fsi/fsi-master.h b/drivers/fsi/fsi-master.h index 12f7b119567d..ee0b46086026 100644 --- a/drivers/fsi/fsi-master.h +++ b/drivers/fsi/fsi-master.h @@ -37,7 +37,24 @@ struct fsi_master { #define dev_to_fsi_master(d) container_of(d, struct fsi_master, dev) +/** + * fsi_master registration & lifetime: the fsi_master_register() and + * fsi_master_unregister() functions will take ownership of the master, and + * ->dev in particular. The registration path performs a get_device(), which + * takes the first reference on the device. Similarly, the unregistration path + * performs a put_device(), which may well drop the last reference. + * + * This means that master implementations *may* need to hold their own + * reference (via get_device()) on master->dev. In particular, if the device's + * ->release callback frees the fsi_master, then fsi_master_unregister will + * invoke this free if no other reference is held. + * + * The same applies for the error path of fsi_master_register; if the call + * fails, dev->release will have been invoked. + */ extern int fsi_master_register(struct fsi_master *master); extern void fsi_master_unregister(struct fsi_master *master); +extern int fsi_master_rescan(struct fsi_master *master); + #endif /* DRIVERS_FSI_MASTER_H */ |