diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 269 |
1 files changed, 226 insertions, 43 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 069a41f116dd..5f89f1e3c2f2 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -27,6 +27,7 @@ I2C slave support (c) 2014 by Wolfram Sang <wsa@sang-engineering.com> */ +#include <dt-bindings/i2c/i2c.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/delay.h> @@ -47,6 +48,7 @@ #include <linux/rwsem.h> #include <linux/pm_runtime.h> #include <linux/pm_domain.h> +#include <linux/pm_wakeirq.h> #include <linux/acpi.h> #include <linux/jump_label.h> #include <asm/uaccess.h> @@ -57,6 +59,9 @@ #define CREATE_TRACE_POINTS #include <trace/events/i2c.h> +#define I2C_ADDR_OFFSET_TEN_BIT 0xa000 +#define I2C_ADDR_OFFSET_SLAVE 0x1000 + /* core_lock protects i2c_adapter_idr, and guarantees that device detection, deletion of detected devices, and attach_adapter calls are serialized */ @@ -567,6 +572,9 @@ static int i2c_generic_recovery(struct i2c_adapter *adap) if (bri->prepare_recovery) bri->prepare_recovery(adap); + bri->set_scl(adap, val); + ndelay(RECOVERY_NDELAY); + /* * By this time SCL is high, as we need to give 9 falling-rising edges */ @@ -597,7 +605,6 @@ static int i2c_generic_recovery(struct i2c_adapter *adap) int i2c_generic_scl_recovery(struct i2c_adapter *adap) { - adap->bus_recovery_info->set_scl(adap, 1); return i2c_generic_recovery(adap); } EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); @@ -639,11 +646,13 @@ static int i2c_device_probe(struct device *dev) if (!client->irq) { int irq = -ENOENT; - if (dev->of_node) - irq = of_irq_get(dev->of_node, 0); - else if (ACPI_COMPANION(dev)) + if (dev->of_node) { + irq = of_irq_get_byname(dev->of_node, "irq"); + if (irq == -EINVAL || irq == -ENODATA) + irq = of_irq_get(dev->of_node, 0); + } else if (ACPI_COMPANION(dev)) { irq = acpi_dev_gpio_irq_get(ACPI_COMPANION(dev), 0); - + } if (irq == -EPROBE_DEFER) return irq; if (irq < 0) @@ -656,23 +665,49 @@ static int i2c_device_probe(struct device *dev) if (!driver->probe || !driver->id_table) return -ENODEV; - if (!device_can_wakeup(&client->dev)) - device_init_wakeup(&client->dev, - client->flags & I2C_CLIENT_WAKE); + if (client->flags & I2C_CLIENT_WAKE) { + int wakeirq = -ENOENT; + + if (dev->of_node) { + wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); + if (wakeirq == -EPROBE_DEFER) + return wakeirq; + } + + device_init_wakeup(&client->dev, true); + + if (wakeirq > 0 && wakeirq != client->irq) + status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); + else if (client->irq > 0) + status = dev_pm_set_wake_irq(dev, wakeirq); + else + status = 0; + + if (status) + dev_warn(&client->dev, "failed to set up wakeup irq"); + } + dev_dbg(dev, "probe\n"); status = of_clk_set_defaults(dev->of_node, false); if (status < 0) - return status; + goto err_clear_wakeup_irq; status = dev_pm_domain_attach(&client->dev, true); if (status != -EPROBE_DEFER) { status = driver->probe(client, i2c_match_id(driver->id_table, client)); if (status) - dev_pm_domain_detach(&client->dev, true); + goto err_detach_pm_domain; } + return 0; + +err_detach_pm_domain: + dev_pm_domain_detach(&client->dev, true); +err_clear_wakeup_irq: + dev_pm_clear_wake_irq(&client->dev); + device_init_wakeup(&client->dev, false); return status; } @@ -692,6 +727,10 @@ static int i2c_device_remove(struct device *dev) } dev_pm_domain_detach(&client->dev, true); + + dev_pm_clear_wake_irq(&client->dev); + device_init_wakeup(&client->dev, false); + return status; } @@ -776,17 +815,32 @@ struct i2c_client *i2c_verify_client(struct device *dev) EXPORT_SYMBOL(i2c_verify_client); +/* Return a unique address which takes the flags of the client into account */ +static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) +{ + unsigned short addr = client->addr; + + /* For some client flags, add an arbitrary offset to avoid collisions */ + if (client->flags & I2C_CLIENT_TEN) + addr |= I2C_ADDR_OFFSET_TEN_BIT; + + if (client->flags & I2C_CLIENT_SLAVE) + addr |= I2C_ADDR_OFFSET_SLAVE; + + return addr; +} + /* This is a permissive address validity check, I2C address map constraints * are purposely not enforced, except for the general call address. */ -static int i2c_check_client_addr_validity(const struct i2c_client *client) +static int i2c_check_addr_validity(unsigned addr, unsigned short flags) { - if (client->flags & I2C_CLIENT_TEN) { + if (flags & I2C_CLIENT_TEN) { /* 10-bit address, all values are valid */ - if (client->addr > 0x3ff) + if (addr > 0x3ff) return -EINVAL; } else { /* 7-bit address, reject the general call address */ - if (client->addr == 0x00 || client->addr > 0x7f) + if (addr == 0x00 || addr > 0x7f) return -EINVAL; } return 0; @@ -796,7 +850,7 @@ static int i2c_check_client_addr_validity(const struct i2c_client *client) * device uses a reserved address, then it shouldn't be probed. 7-bit * addressing is assumed, 10-bit address devices are rare and should be * explicitly enumerated. */ -static int i2c_check_addr_validity(unsigned short addr) +static int i2c_check_7bit_addr_validity_strict(unsigned short addr) { /* * Reserved addresses per I2C specification: @@ -818,7 +872,7 @@ static int __i2c_check_addr_busy(struct device *dev, void *addrp) struct i2c_client *client = i2c_verify_client(dev); int addr = *(int *)addrp; - if (client && client->addr == addr) + if (client && i2c_encode_flags_to_addr(client) == addr) return -EBUSY; return 0; } @@ -921,10 +975,8 @@ static void i2c_dev_set_name(struct i2c_adapter *adap, return; } - /* For 10-bit clients, add an arbitrary offset to avoid collisions */ dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), - client->addr | ((client->flags & I2C_CLIENT_TEN) - ? 0xa000 : 0)); + i2c_encode_flags_to_addr(client)); } /** @@ -966,8 +1018,7 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) strlcpy(client->name, info->type, sizeof(client->name)); - /* Check for address validity */ - status = i2c_check_client_addr_validity(client); + status = i2c_check_addr_validity(client->addr, client->flags); if (status) { dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); @@ -975,7 +1026,7 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) } /* Check for address business */ - status = i2c_check_addr_busy(adap, client->addr); + status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); if (status) goto out_err; @@ -1012,6 +1063,8 @@ EXPORT_SYMBOL_GPL(i2c_new_device); */ void i2c_unregister_device(struct i2c_client *client) { + if (client->dev.of_node) + of_node_clear_flag(client->dev.of_node, OF_POPULATED); device_unregister(&client->dev); } EXPORT_SYMBOL_GPL(i2c_unregister_device); @@ -1138,6 +1191,16 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, return -EINVAL; } + if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { + info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; + info.flags |= I2C_CLIENT_TEN; + } + + if (info.addr & I2C_ADDR_OFFSET_SLAVE) { + info.addr &= ~I2C_ADDR_OFFSET_SLAVE; + info.flags |= I2C_CLIENT_SLAVE; + } + client = i2c_new_device(adap, &info); if (!client) return -EINVAL; @@ -1189,7 +1252,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, i2c_adapter_depth(adap)); list_for_each_entry_safe(client, next, &adap->userspace_clients, detected) { - if (client->addr == addr) { + if (i2c_encode_flags_to_addr(client) == addr) { dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", "delete_device", client->name, client->addr); @@ -1269,7 +1332,8 @@ static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, struct i2c_client *result; struct i2c_board_info info = {}; struct dev_archdata dev_ad = {}; - const __be32 *addr; + const __be32 *addr_be; + u32 addr; int len; dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); @@ -1280,20 +1344,31 @@ static struct i2c_client *of_i2c_register_device(struct i2c_adapter *adap, return ERR_PTR(-EINVAL); } - addr = of_get_property(node, "reg", &len); - if (!addr || (len < sizeof(*addr))) { + addr_be = of_get_property(node, "reg", &len); + if (!addr_be || (len < sizeof(*addr_be))) { dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", node->full_name); return ERR_PTR(-EINVAL); } - info.addr = be32_to_cpup(addr); - if (info.addr > (1 << 10) - 1) { + addr = be32_to_cpup(addr_be); + if (addr & I2C_TEN_BIT_ADDRESS) { + addr &= ~I2C_TEN_BIT_ADDRESS; + info.flags |= I2C_CLIENT_TEN; + } + + if (addr & I2C_OWN_SLAVE_ADDRESS) { + addr &= ~I2C_OWN_SLAVE_ADDRESS; + info.flags |= I2C_CLIENT_SLAVE; + } + + if (i2c_check_addr_validity(addr, info.flags)) { dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", info.addr, node->full_name); return ERR_PTR(-EINVAL); } + info.addr = addr; info.of_node = of_node_get(node); info.archdata = &dev_ad; @@ -1320,8 +1395,11 @@ static void of_i2c_register_devices(struct i2c_adapter *adap) dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); - for_each_available_child_of_node(adap->dev.of_node, node) + for_each_available_child_of_node(adap->dev.of_node, node) { + if (of_node_test_and_set_flag(node, OF_POPULATED)) + continue; of_i2c_register_device(adap, node); + } } static int of_dev_node_match(struct device *dev, void *data) @@ -1333,13 +1411,17 @@ static int of_dev_node_match(struct device *dev, void *data) struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) { struct device *dev; + struct i2c_client *client; - dev = bus_find_device(&i2c_bus_type, NULL, node, - of_dev_node_match); + dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); if (!dev) return NULL; - return i2c_verify_client(dev); + client = i2c_verify_client(dev); + if (!client) + put_device(dev); + + return client; } EXPORT_SYMBOL(of_find_i2c_device_by_node); @@ -1347,15 +1429,37 @@ EXPORT_SYMBOL(of_find_i2c_device_by_node); struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) { struct device *dev; + struct i2c_adapter *adapter; - dev = bus_find_device(&i2c_bus_type, NULL, node, - of_dev_node_match); + dev = bus_find_device(&i2c_bus_type, NULL, node, of_dev_node_match); if (!dev) return NULL; - return i2c_verify_adapter(dev); + adapter = i2c_verify_adapter(dev); + if (!adapter) + put_device(dev); + + return adapter; } EXPORT_SYMBOL(of_find_i2c_adapter_by_node); + +/* must call i2c_put_adapter() when done with returned i2c_adapter device */ +struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) +{ + struct i2c_adapter *adapter; + + adapter = of_find_i2c_adapter_by_node(node); + if (!adapter) + return NULL; + + if (!try_module_get(adapter->owner)) { + put_device(&adapter->dev); + adapter = NULL; + } + + return adapter; +} +EXPORT_SYMBOL(of_get_i2c_adapter_by_node); #else static void of_i2c_register_devices(struct i2c_adapter *adap) { } #endif /* CONFIG_OF */ @@ -1853,6 +1957,11 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action, if (adap == NULL) return NOTIFY_OK; /* not for us */ + if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) { + put_device(&adap->dev); + return NOTIFY_OK; + } + client = of_i2c_register_device(adap, rd->dn); put_device(&adap->dev); @@ -1863,6 +1972,10 @@ static int of_i2c_notify(struct notifier_block *nb, unsigned long action, } break; case OF_RECONFIG_CHANGE_REMOVE: + /* already depopulated? */ + if (!of_node_check_flag(rd->dn, OF_POPULATED)) + return NOTIFY_OK; + /* find our device by node */ client = of_find_i2c_device_by_node(rd->dn); if (client == NULL) @@ -2238,14 +2351,14 @@ static int i2c_detect_address(struct i2c_client *temp_client, int err; /* Make sure the address is valid */ - err = i2c_check_addr_validity(addr); + err = i2c_check_7bit_addr_validity_strict(addr); if (err) { dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", addr); return err; } - /* Skip if already in use */ + /* Skip if already in use (7 bit, no need to encode flags) */ if (i2c_check_addr_busy(adapter, addr)) return 0; @@ -2355,13 +2468,13 @@ i2c_new_probed_device(struct i2c_adapter *adap, for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { /* Check address validity */ - if (i2c_check_addr_validity(addr_list[i]) < 0) { + if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { dev_warn(&adap->dev, "Invalid 7-bit address " "0x%02x\n", addr_list[i]); continue; } - /* Check address availability */ + /* Check address availability (7 bit, no need to encode flags) */ if (i2c_check_addr_busy(adap, addr_list[i])) { dev_dbg(&adap->dev, "Address 0x%02x already in " "use, not probing\n", addr_list[i]); @@ -2389,9 +2502,15 @@ struct i2c_adapter *i2c_get_adapter(int nr) mutex_lock(&core_lock); adapter = idr_find(&i2c_adapter_idr, nr); - if (adapter && !try_module_get(adapter->owner)) + if (!adapter) + goto exit; + + if (try_module_get(adapter->owner)) + get_device(&adapter->dev); + else adapter = NULL; + exit: mutex_unlock(&core_lock); return adapter; } @@ -2399,8 +2518,11 @@ EXPORT_SYMBOL(i2c_get_adapter); void i2c_put_adapter(struct i2c_adapter *adap) { - if (adap) - module_put(adap->owner); + if (!adap) + return; + + put_device(&adap->dev); + module_put(adap->owner); } EXPORT_SYMBOL(i2c_put_adapter); @@ -2918,6 +3040,63 @@ trace: } EXPORT_SYMBOL(i2c_smbus_xfer); +/** + * i2c_smbus_read_i2c_block_data_or_emulated - read block or emulate + * @client: Handle to slave device + * @command: Byte interpreted by slave + * @length: Size of data block; SMBus allows at most I2C_SMBUS_BLOCK_MAX bytes + * @values: Byte array into which data will be read; big enough to hold + * the data returned by the slave. SMBus allows at most + * I2C_SMBUS_BLOCK_MAX bytes. + * + * This executes the SMBus "block read" protocol if supported by the adapter. + * If block read is not supported, it emulates it using either word or byte + * read protocols depending on availability. + * + * The addresses of the I2C slave device that are accessed with this function + * must be mapped to a linear region, so that a block read will have the same + * effect as a byte read. Before using this function you must double-check + * if the I2C slave does support exchanging a block transfer with a byte + * transfer. + */ +s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, + u8 command, u8 length, u8 *values) +{ + u8 i = 0; + int status; + + if (length > I2C_SMBUS_BLOCK_MAX) + length = I2C_SMBUS_BLOCK_MAX; + + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) + return i2c_smbus_read_i2c_block_data(client, command, length, values); + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) + return -EOPNOTSUPP; + + if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)) { + while ((i + 2) <= length) { + status = i2c_smbus_read_word_data(client, command + i); + if (status < 0) + return status; + values[i] = status & 0xff; + values[i + 1] = status >> 8; + i += 2; + } + } + + while (i < length) { + status = i2c_smbus_read_byte_data(client, command + i); + if (status < 0) + return status; + values[i] = status; + i++; + } + + return i; +} +EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data_or_emulated); + #if IS_ENABLED(CONFIG_I2C_SLAVE) int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb) { @@ -2928,9 +3107,13 @@ int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb) return -EINVAL; } + if (!(client->flags & I2C_CLIENT_SLAVE)) + dev_warn(&client->dev, "%s: client slave flag not set. You might see address collisions\n", + __func__); + if (!(client->flags & I2C_CLIENT_TEN)) { /* Enforce stricter address checking */ - ret = i2c_check_addr_validity(client->addr); + ret = i2c_check_7bit_addr_validity_strict(client->addr); if (ret) { dev_err(&client->dev, "%s: invalid address\n", __func__); return ret; |