diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mt65xx.c | 65 |
1 files changed, 46 insertions, 19 deletions
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c index 45d61714c81b..9bedf0bf2c4d 100644 --- a/drivers/i2c/busses/i2c-mt65xx.c +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -50,7 +50,6 @@ #define I2C_FS_START_CON 0x1800 #define I2C_TIME_CLR_VALUE 0x0000 #define I2C_TIME_DEFAULT_VALUE 0x0003 -#define I2C_FS_TIME_INIT_VALUE 0x1303 #define I2C_WRRD_TRANAC_VALUE 0x0002 #define I2C_RD_TRANAC_VALUE 0x0001 @@ -154,6 +153,7 @@ struct mtk_i2c { bool use_push_pull; /* IO config push-pull mode */ u16 irq_stat; /* interrupt status */ + unsigned int clk_src_div; unsigned int speed_hz; /* The speed in transfer */ enum mtk_trans_op op; u16 timing_reg; @@ -285,23 +285,20 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c) * less than or equal to i2c->speed_hz. The calculation try to get * sample_cnt and step_cn */ -static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk, - unsigned int clock_div) +static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, + unsigned int target_speed, + unsigned int *timing_step_cnt, + unsigned int *timing_sample_cnt) { - unsigned int clk_src; unsigned int step_cnt; unsigned int sample_cnt; unsigned int max_step_cnt; - unsigned int target_speed; unsigned int base_sample_cnt = MAX_SAMPLE_CNT_DIV; unsigned int base_step_cnt; unsigned int opt_div; unsigned int best_mul; unsigned int cnt_mul; - clk_src = parent_clk / clock_div; - target_speed = i2c->speed_hz; - if (target_speed > MAX_HS_MODE_SPEED) target_speed = MAX_HS_MODE_SPEED; @@ -347,16 +344,48 @@ static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk, return -EINVAL; } - step_cnt--; - sample_cnt--; + *timing_step_cnt = step_cnt - 1; + *timing_sample_cnt = sample_cnt - 1; + + return 0; +} + +static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk) +{ + unsigned int clk_src; + unsigned int step_cnt; + unsigned int sample_cnt; + unsigned int target_speed; + int ret; + + clk_src = parent_clk / i2c->clk_src_div; + target_speed = i2c->speed_hz; if (target_speed > MAX_FS_MODE_SPEED) { + /* Set master code speed register */ + ret = mtk_i2c_calculate_speed(i2c, clk_src, MAX_FS_MODE_SPEED, + &step_cnt, &sample_cnt); + if (ret < 0) + return ret; + + i2c->timing_reg = (sample_cnt << 8) | step_cnt; + /* Set the high speed mode register */ - i2c->timing_reg = I2C_FS_TIME_INIT_VALUE; + ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed, + &step_cnt, &sample_cnt); + if (ret < 0) + return ret; + i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE | (sample_cnt << 12) | (step_cnt << 8); } else { - i2c->timing_reg = (sample_cnt << 8) | (step_cnt << 0); + ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed, + &step_cnt, &sample_cnt); + if (ret < 0) + return ret; + + i2c->timing_reg = (sample_cnt << 8) | step_cnt; + /* Disable the high speed transaction */ i2c->high_speed_reg = I2C_TIME_CLR_VALUE; } @@ -647,8 +676,7 @@ static const struct i2c_algorithm mtk_i2c_algorithm = { .functionality = mtk_i2c_functionality, }; -static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c, - unsigned int *clk_src_div) +static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c) { int ret; @@ -656,11 +684,11 @@ static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c, if (ret < 0) i2c->speed_hz = I2C_DEFAULT_SPEED; - ret = of_property_read_u32(np, "clock-div", clk_src_div); + ret = of_property_read_u32(np, "clock-div", &i2c->clk_src_div); if (ret < 0) return ret; - if (*clk_src_div == 0) + if (i2c->clk_src_div == 0) return -EINVAL; i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic"); @@ -676,7 +704,6 @@ static int mtk_i2c_probe(struct platform_device *pdev) int ret = 0; struct mtk_i2c *i2c; struct clk *clk; - unsigned int clk_src_div; struct resource *res; int irq; @@ -684,7 +711,7 @@ static int mtk_i2c_probe(struct platform_device *pdev) if (!i2c) return -ENOMEM; - ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c, &clk_src_div); + ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c); if (ret) return -EINVAL; @@ -745,7 +772,7 @@ static int mtk_i2c_probe(struct platform_device *pdev) strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name)); - ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk), clk_src_div); + ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk)); if (ret) { dev_err(&pdev->dev, "Failed to set the speed.\n"); return -EINVAL; |