From 565e328b959b58c181fdec33b2e161ada90dd521 Mon Sep 17 00:00:00 2001 From: Jun Chen Date: Mon, 2 Mar 2020 16:58:55 +0800 Subject: [PATCH] i2c: designware_i2c: check is high speed possible support 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 Signed-off-by: Jun Chen --- drivers/i2c/designware_i2c.c | 10 ++++++++++ drivers/i2c/designware_i2c.h | 3 +++ 2 files changed, 13 insertions(+) diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c index 9186fcb..f4fbf3b 100644 --- a/drivers/i2c/designware_i2c.c +++ b/drivers/i2c/designware_i2c.c @@ -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; 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 */ @@ -219,6 +222,13 @@ static int calc_bus_speed(struct dw_i2c *priv, int speed, ulong bus_clk, else 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 */ if (!priv || !priv->has_spk_cnt) spk_cnt = 0; diff --git a/drivers/i2c/designware_i2c.h b/drivers/i2c/designware_i2c.h index 61a882c..23f311b 100644 --- a/drivers/i2c/designware_i2c.h +++ b/drivers/i2c/designware_i2c.h @@ -138,6 +138,9 @@ struct i2c_regs { #define IC_STATUS_TFNF 0x0002 #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 * -- 2.7.4