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i2c: designware_i2c: check is high speed possible support

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To read IC_COMP_PARAM_1[3:2] to check is high speed possible,
and fall back to fast mode if not.

Signed-off-by: Jun Chen <ptchentw@gmail.com>
Signed-off-by: Jun Chen <jun.chen@vatics.com>
This commit is contained in:
Jun Chen 2020-03-02 16:58:55 +08:00 • committed by Heiko Schocher
parent 70c894f85e
commit 565e328b95
2 changed files with 13 additions and 0 deletions
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10
drivers/i2c/designware_i2c.c
View file

@ -203,9 +203,12 @@ static int calc_bus_speed(struct dw_i2c *priv, int speed, ulong bus_clk,
const struct dw_scl_sda_cfg *scl_sda_cfg = NULL; const struct dw_scl_sda_cfg *scl_sda_cfg = NULL;
struct i2c_regs *regs = priv->regs; struct i2c_regs *regs = priv->regs;
enum i2c_speed_mode i2c_spd; enum i2c_speed_mode i2c_spd;
u32 comp_param1;
int spk_cnt; int spk_cnt;
int ret; int ret;
comp_param1 = readl(&regs->comp_param1);
if (priv) if (priv)
scl_sda_cfg = priv->scl_sda_cfg; scl_sda_cfg = priv->scl_sda_cfg;
/* Allow high speed if there is no config, or the config allows it */ /* Allow high speed if there is no config, or the config allows it */
@ -219,6 +222,13 @@ static int calc_bus_speed(struct dw_i2c *priv, int speed, ulong bus_clk,
else else
i2c_spd = IC_SPEED_MODE_STANDARD; i2c_spd = IC_SPEED_MODE_STANDARD;
/* Check is high speed possible and fall back to fast mode if not */
if (i2c_spd == IC_SPEED_MODE_HIGH) {
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;
}
/* Get the proper spike-suppression count based on target speed */ /* Get the proper spike-suppression count based on target speed */
if (!priv || !priv->has_spk_cnt) if (!priv || !priv->has_spk_cnt)
spk_cnt = 0; spk_cnt = 0;

3
drivers/i2c/designware_i2c.h
View file

@ -138,6 +138,9 @@ struct i2c_regs {
#define IC_STATUS_TFNF 0x0002 #define IC_STATUS_TFNF 0x0002
#define IC_STATUS_ACT 0x0001 #define IC_STATUS_ACT 0x0001
#define DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH (BIT(2) | BIT(3))
#define DW_IC_COMP_PARAM_1_SPEED_MODE_MASK (BIT(2) | BIT(3))
/** /**
* struct dw_scl_sda_cfg - I2C timing configuration * struct dw_scl_sda_cfg - I2C timing configuration
* *