diff options
| author | Simon Glass <sjg@chromium.org> | 2020-04-22 10:13:53 -0600 |
|---|---|---|
| committer | Heiko Schocher <hs@denx.de> | 2020-05-28 05:50:00 +0200 |
| commit | bcf08503f571553074a4e9563977225446c183fa (patch) | |
| tree | 08e36d1417a4c0797e60a65a56dc81389be5247c /drivers/i2c/designware_i2c.c | |
| parent | ab80137cc436e977ef91a154372ae5aeae3f4fb0 (diff) | |
i2c: designware_i2c: Tidy up use of NULL priv
At present we still have pre-driver-model code in this driver and it makes
things a bit confusing. In particular calc_bus_speed() is called with priv
as NULL if not using driver model.
This results in spk_cnt and comp_param1 being read from an invalid address
if not using driver model. For comp_param1 this may not cause problems if
reading from addresses close to 0 happens to be allowed, as high speed is
only supported by DM code. But spk_cnt is subsequently used to calculate
the bus periods and so this may cause problems (e.g. on spear600 board
which has not been migrated yet).
Add a new parameter regs parameter to calc_bus_speed() and add more
comments to this function and to _dw_i2c_set_bus_speed(), which calls it.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Diffstat (limited to 'drivers/i2c/designware_i2c.c')
| -rw-r--r-- | drivers/i2c/designware_i2c.c | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c index 42ee7d523e..c6a20721f6 100644 --- a/drivers/i2c/designware_i2c.c +++ b/drivers/i2c/designware_i2c.c @@ -199,18 +199,24 @@ 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 +231,9 @@ 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 +269,14 @@ 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 +286,7 @@ 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; |