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
Reported-by: Heinrich Schuchardt
---
drivers/i2c/designware_i2c.c | 34 +++---
1 file changed, 23 insertions(+), 11 deletions(-)
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index 088a6f3efb..ac170769f4 100644
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -197,18 +197,24 @@ 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(>comp_param1);
-
if (priv)
scl_sda_cfg = priv->scl_sda_cfg;
/* Allow high speed if there is no config, or the config allows it */
@@ -223,6 +229,9 @@ 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(>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;
@@ -258,11 +267,14 @@ 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)
@@ -272,7 +284,7 @@ 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, );
+ ret = calc_bus_speed(priv, i2c_base, speed, bus_clk, );
if (ret)
return ret;
--
2.26.1.301.g55bc3eb7cb9-goog
