diff options
Diffstat (limited to 'drivers/tty/serial/max310x.c')
| -rw-r--r-- | drivers/tty/serial/max310x.c | 135 |
1 files changed, 134 insertions, 1 deletions
diff --git a/drivers/tty/serial/max310x.c b/drivers/tty/serial/max310x.c index b90281ac54c8..ed1aaa19854f 100644 --- a/drivers/tty/serial/max310x.c +++ b/drivers/tty/serial/max310x.c @@ -14,6 +14,7 @@ #include <linux/delay.h> #include <linux/device.h> #include <linux/gpio/driver.h> +#include <linux/i2c.h> #include <linux/module.h> #include <linux/mod_devicetable.h> #include <linux/property.h> @@ -73,6 +74,7 @@ /* Extended registers */ #define MAX310X_SPI_REVID_EXTREG MAX310X_REG_05 /* Revision ID */ +#define MAX310X_I2C_REVID_EXTREG (0x25) /* Revision ID */ /* IRQ register bits */ #define MAX310X_IRQ_LSR_BIT (1 << 0) /* LSR interrupt */ @@ -260,6 +262,10 @@ struct max310x_if_cfg { }; struct max310x_devtype { + struct { + unsigned short min; + unsigned short max; + } slave_addr; char name[9]; int nr; u8 mode1; @@ -431,6 +437,10 @@ static const struct max310x_devtype max3107_devtype = { .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT | MAX310X_MODE1_IRQSEL_BIT, .detect = max3107_detect, .power = max310x_power, + .slave_addr = { + .min = 0x2c, + .max = 0x2f, + }, }; static const struct max310x_devtype max3108_devtype = { @@ -439,6 +449,10 @@ static const struct max310x_devtype max3108_devtype = { .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT, .detect = max3108_detect, .power = max310x_power, + .slave_addr = { + .min = 0x60, + .max = 0x6f, + }, }; static const struct max310x_devtype max3109_devtype = { @@ -447,6 +461,10 @@ static const struct max310x_devtype max3109_devtype = { .mode1 = MAX310X_MODE1_AUTOSLEEP_BIT, .detect = max3109_detect, .power = max310x_power, + .slave_addr = { + .min = 0x60, + .max = 0x6f, + }, }; static const struct max310x_devtype max14830_devtype = { @@ -455,6 +473,10 @@ static const struct max310x_devtype max14830_devtype = { .mode1 = MAX310X_MODE1_IRQSEL_BIT, .detect = max14830_detect, .power = max14830_power, + .slave_addr = { + .min = 0x60, + .max = 0x6f, + }, }; static bool max310x_reg_writeable(struct device *dev, unsigned int reg) @@ -1557,6 +1579,97 @@ static struct spi_driver max310x_spi_driver = { }; #endif +#ifdef CONFIG_I2C +static int max310x_i2c_extended_reg_enable(struct device *dev, bool enable) +{ + return 0; +} + +static struct regmap_config regcfg_i2c = { + .reg_bits = 8, + .val_bits = 8, + .cache_type = REGCACHE_RBTREE, + .writeable_reg = max310x_reg_writeable, + .volatile_reg = max310x_reg_volatile, + .precious_reg = max310x_reg_precious, + .max_register = MAX310X_I2C_REVID_EXTREG, +}; + +static const struct max310x_if_cfg max310x_i2c_if_cfg = { + .extended_reg_enable = max310x_i2c_extended_reg_enable, + .rev_id_reg = MAX310X_I2C_REVID_EXTREG, +}; + +static unsigned short max310x_i2c_slave_addr(unsigned short addr, + unsigned int nr) +{ + /* + * For MAX14830 and MAX3109, the slave address depends on what the + * A0 and A1 pins are tied to. + * See Table I2C Address Map of the datasheet. + * Based on that table, the following formulas were determined. + * UART1 - UART0 = 0x10 + * UART2 - UART1 = 0x20 + 0x10 + * UART3 - UART2 = 0x10 + */ + + addr -= nr * 0x10; + + if (nr >= 2) + addr -= 0x20; + + return addr; +} + +static int max310x_i2c_probe(struct i2c_client *client) +{ + const struct max310x_devtype *devtype = + device_get_match_data(&client->dev); + struct i2c_client *port_client; + struct regmap *regmaps[4]; + unsigned int i; + u8 port_addr; + + if (client->addr < devtype->slave_addr.min || + client->addr > devtype->slave_addr.max) + return dev_err_probe(&client->dev, -EINVAL, + "Slave addr 0x%x outside of range [0x%x, 0x%x]\n", + client->addr, devtype->slave_addr.min, + devtype->slave_addr.max); + + regmaps[0] = devm_regmap_init_i2c(client, ®cfg_i2c); + + for (i = 1; i < devtype->nr; i++) { + port_addr = max310x_i2c_slave_addr(client->addr, i); + port_client = devm_i2c_new_dummy_device(&client->dev, + client->adapter, + port_addr); + + regmaps[i] = devm_regmap_init_i2c(port_client, ®cfg_i2c); + } + + return max310x_probe(&client->dev, devtype, &max310x_i2c_if_cfg, + regmaps, client->irq); +} + +static int max310x_i2c_remove(struct i2c_client *client) +{ + max310x_remove(&client->dev); + + return 0; +} + +static struct i2c_driver max310x_i2c_driver = { + .driver = { + .name = MAX310X_NAME, + .of_match_table = max310x_dt_ids, + .pm = &max310x_pm_ops, + }, + .probe_new = max310x_i2c_probe, + .remove = max310x_i2c_remove, +}; +#endif + static int __init max310x_uart_init(void) { int ret; @@ -1570,15 +1683,35 @@ static int __init max310x_uart_init(void) #ifdef CONFIG_SPI_MASTER ret = spi_register_driver(&max310x_spi_driver); if (ret) - uart_unregister_driver(&max310x_uart); + goto err_spi_register; +#endif + +#ifdef CONFIG_I2C + ret = i2c_add_driver(&max310x_i2c_driver); + if (ret) + goto err_i2c_register; #endif + return 0; + +#ifdef CONFIG_I2C +err_i2c_register: + spi_unregister_driver(&max310x_spi_driver); +#endif + +err_spi_register: + uart_unregister_driver(&max310x_uart); + return ret; } module_init(max310x_uart_init); static void __exit max310x_uart_exit(void) { +#ifdef CONFIG_I2C + i2c_del_driver(&max310x_i2c_driver); +#endif + #ifdef CONFIG_SPI_MASTER spi_unregister_driver(&max310x_spi_driver); #endif |