diff options
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlxsw/i2c.c')
| -rw-r--r-- | drivers/net/ethernet/mellanox/mlxsw/i2c.c | 92 |
1 files changed, 88 insertions, 4 deletions
diff --git a/drivers/net/ethernet/mellanox/mlxsw/i2c.c b/drivers/net/ethernet/mellanox/mlxsw/i2c.c index 939b692ffc33..f5f5f8dc3d19 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/i2c.c +++ b/drivers/net/ethernet/mellanox/mlxsw/i2c.c @@ -9,6 +9,7 @@ #include <linux/mutex.h> #include <linux/module.h> #include <linux/mod_devicetable.h> +#include <linux/platform_data/mlxreg.h> #include <linux/slab.h> #include "cmd.h" @@ -51,6 +52,15 @@ #define MLXSW_I2C_TIMEOUT_MSECS 5000 #define MLXSW_I2C_MAX_DATA_SIZE 256 +/* Driver can be initialized by kernel platform driver or from the user + * space. In the first case IRQ line number is passed through the platform + * data, otherwise default IRQ line is to be used. Default IRQ is relevant + * only for specific I2C slave address, allowing 3.4 MHz I2C path to the chip + * (special hardware feature for I2C acceleration). + */ +#define MLXSW_I2C_DEFAULT_IRQ 17 +#define MLXSW_FAST_I2C_SLAVE 0x37 + /** * struct mlxsw_i2c - device private data: * @cmd: command attributes; @@ -63,6 +73,9 @@ * @core: switch core pointer; * @bus_info: bus info block; * @block_size: maximum block size allowed to pass to under layer; + * @pdata: device platform data; + * @irq_work: interrupts work item; + * @irq: IRQ line number; */ struct mlxsw_i2c { struct { @@ -76,6 +89,9 @@ struct mlxsw_i2c { struct mlxsw_core *core; struct mlxsw_bus_info bus_info; u16 block_size; + struct mlxreg_core_hotplug_platform_data *pdata; + struct work_struct irq_work; + int irq; }; #define MLXSW_I2C_READ_MSG(_client, _addr_buf, _buf, _len) { \ @@ -546,6 +562,67 @@ static void mlxsw_i2c_fini(void *bus_priv) mlxsw_i2c->core = NULL; } +static void mlxsw_i2c_work_handler(struct work_struct *work) +{ + struct mlxsw_i2c *mlxsw_i2c; + + mlxsw_i2c = container_of(work, struct mlxsw_i2c, irq_work); + mlxsw_core_irq_event_handlers_call(mlxsw_i2c->core); +} + +static irqreturn_t mlxsw_i2c_irq_handler(int irq, void *dev) +{ + struct mlxsw_i2c *mlxsw_i2c = dev; + + mlxsw_core_schedule_work(&mlxsw_i2c->irq_work); + + /* Interrupt handler shares IRQ line with 'main' interrupt handler. + * Return here IRQ_NONE, while main handler will return IRQ_HANDLED. + */ + return IRQ_NONE; +} + +static int mlxsw_i2c_irq_init(struct mlxsw_i2c *mlxsw_i2c, u8 addr) +{ + int err; + + /* Initialize interrupt handler if system hotplug driver is reachable, + * otherwise interrupt line is not enabled and interrupts will not be + * raised to CPU. Also request_irq() call will be not valid. + */ + if (!IS_REACHABLE(CONFIG_MLXREG_HOTPLUG)) + return 0; + + /* Set default interrupt line. */ + if (mlxsw_i2c->pdata && mlxsw_i2c->pdata->irq) + mlxsw_i2c->irq = mlxsw_i2c->pdata->irq; + else if (addr == MLXSW_FAST_I2C_SLAVE) + mlxsw_i2c->irq = MLXSW_I2C_DEFAULT_IRQ; + + if (!mlxsw_i2c->irq) + return 0; + + INIT_WORK(&mlxsw_i2c->irq_work, mlxsw_i2c_work_handler); + err = request_irq(mlxsw_i2c->irq, mlxsw_i2c_irq_handler, + IRQF_TRIGGER_FALLING | IRQF_SHARED, "mlxsw-i2c", + mlxsw_i2c); + if (err) { + dev_err(mlxsw_i2c->bus_info.dev, "Failed to request irq: %d\n", + err); + return err; + } + + return 0; +} + +static void mlxsw_i2c_irq_fini(struct mlxsw_i2c *mlxsw_i2c) +{ + if (!IS_REACHABLE(CONFIG_MLXREG_HOTPLUG) || !mlxsw_i2c->irq) + return; + cancel_work_sync(&mlxsw_i2c->irq_work); + free_irq(mlxsw_i2c->irq, mlxsw_i2c); +} + static const struct mlxsw_bus mlxsw_i2c_bus = { .kind = "i2c", .init = mlxsw_i2c_init, @@ -638,31 +715,38 @@ static int mlxsw_i2c_probe(struct i2c_client *client, mlxsw_i2c->bus_info.dev = &client->dev; mlxsw_i2c->bus_info.low_frequency = true; mlxsw_i2c->dev = &client->dev; + mlxsw_i2c->pdata = client->dev.platform_data; + + err = mlxsw_i2c_irq_init(mlxsw_i2c, client->addr); + if (err) + goto errout; err = mlxsw_core_bus_device_register(&mlxsw_i2c->bus_info, &mlxsw_i2c_bus, mlxsw_i2c, false, NULL, NULL); if (err) { dev_err(&client->dev, "Fail to register core bus\n"); - return err; + goto err_bus_device_register; } return 0; +err_bus_device_register: + mlxsw_i2c_irq_fini(mlxsw_i2c); errout: + mutex_destroy(&mlxsw_i2c->cmd.lock); i2c_set_clientdata(client, NULL); return err; } -static int mlxsw_i2c_remove(struct i2c_client *client) +static void mlxsw_i2c_remove(struct i2c_client *client) { struct mlxsw_i2c *mlxsw_i2c = i2c_get_clientdata(client); mlxsw_core_bus_device_unregister(mlxsw_i2c->core, false); + mlxsw_i2c_irq_fini(mlxsw_i2c); mutex_destroy(&mlxsw_i2c->cmd.lock); - - return 0; } int mlxsw_i2c_driver_register(struct i2c_driver *i2c_driver) |