diff options
Diffstat (limited to 'drivers/i2c/designware_i2c.c')
| -rw-r--r-- | drivers/i2c/designware_i2c.c | 51 |
1 files changed, 40 insertions, 11 deletions
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c index 42ee7d523e..3616e2105f 100644 --- a/drivers/i2c/designware_i2c.c +++ b/drivers/i2c/designware_i2c.c @@ -18,6 +18,12 @@ #include <dm/device_compat.h> #include <linux/err.h> +/* + * This assigned unique hex value is constant and is derived from the two ASCII + * letters 'DW' followed by a 16-bit unsigned number + */ +#define DW_I2C_COMP_TYPE 0x44570140 + #ifdef CONFIG_SYS_I2C_DW_ENABLE_STATUS_UNSUPPORTED static int dw_i2c_enable(struct i2c_regs *i2c_base, bool enable) { @@ -199,18 +205,24 @@ static int dw_i2c_calc_timing(struct dw_i2c *priv, enum i2c_speed_mode mode, return 0; } -static int calc_bus_speed(struct dw_i2c *priv, int speed, ulong bus_clk, - struct dw_i2c_speed_config *config) +/** + * calc_bus_speed() - Calculate the config to use for a particular i2c speed + * + * @priv: Private information for the driver (NULL if not using driver model) + * @i2c_base: Registers for the I2C controller + * @speed: Required i2c speed in Hz + * @bus_clk: Input clock to the I2C controller in Hz (e.g. IC_CLK) + * @config: Returns the config to use for this speed + * @return 0 if OK, -ve on error + */ +static int calc_bus_speed(struct dw_i2c *priv, struct i2c_regs *regs, int speed, + ulong bus_clk, struct dw_i2c_speed_config *config) { const struct dw_scl_sda_cfg *scl_sda_cfg = NULL; - struct i2c_regs *regs = priv->regs; enum i2c_speed_mode i2c_spd; - u32 comp_param1; int spk_cnt; int ret; - comp_param1 = readl(®s->comp_param1); - if (priv) scl_sda_cfg = priv->scl_sda_cfg; /* Allow high speed if there is no config, or the config allows it */ @@ -225,6 +237,9 @@ static int calc_bus_speed(struct dw_i2c *priv, int speed, ulong bus_clk, /* Check is high speed possible and fall back to fast mode if not */ if (i2c_spd == IC_SPEED_MODE_HIGH) { + u32 comp_param1; + + comp_param1 = readl(®s->comp_param1); if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK) != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) i2c_spd = IC_SPEED_MODE_FAST; @@ -260,11 +275,14 @@ static int calc_bus_speed(struct dw_i2c *priv, int speed, ulong bus_clk, return 0; } -/* - * _dw_i2c_set_bus_speed - Set the i2c speed - * @speed: required i2c speed +/** + * _dw_i2c_set_bus_speed() - Set the i2c speed * - * Set the i2c speed. + * @priv: Private information for the driver (NULL if not using driver model) + * @i2c_base: Registers for the I2C controller + * @speed: Required i2c speed in Hz + * @bus_clk: Input clock to the I2C controller in Hz (e.g. IC_CLK) + * @return 0 if OK, -ve on error */ static int _dw_i2c_set_bus_speed(struct dw_i2c *priv, struct i2c_regs *i2c_base, unsigned int speed, unsigned int bus_clk) @@ -274,7 +292,7 @@ static int _dw_i2c_set_bus_speed(struct dw_i2c *priv, struct i2c_regs *i2c_base, unsigned int ena; int ret; - ret = calc_bus_speed(priv, speed, bus_clk, &config); + ret = calc_bus_speed(priv, i2c_base, speed, bus_clk, &config); if (ret) return ret; @@ -754,6 +772,17 @@ int designware_i2c_ofdata_to_platdata(struct udevice *bus) int designware_i2c_probe(struct udevice *bus) { struct dw_i2c *priv = dev_get_priv(bus); + uint comp_type; + + comp_type = readl(&priv->regs->comp_type); + if (comp_type != DW_I2C_COMP_TYPE) { + log_err("I2C bus %s has unknown type %#x\n", bus->name, + comp_type); + return -ENXIO; + } + + log_info("I2C bus %s version %#x\n", bus->name, + readl(&priv->regs->comp_version)); return __dw_i2c_init(priv->regs, 0, 0); } |