From d57f5dedde18253d5c72a823c0a7ff3b20b57560 Mon Sep 17 00:00:00 2001 From: Laxman Dewangan Date: Tue, 30 Jun 2015 16:24:27 +0530 Subject: [PATCH] i2c: tegra: add support for fast plus (FM+) mode clock rate Tegra I2C controller required to configure the clock divisor register inside controller to different value based on the clock speed. The recommended clock divisor for the I2C controller for standard/fast mode is 0x19 and for fast-mode plus is 0x10. Add support to configure clock divisor register of I2C controller based on bus clock rate. This clock divisor is supported form T114 onwards. Signed-off-by: Chaitanya Bandi Signed-off-by: Laxman Dewangan Tested-by: Stephen Warren Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-tegra.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 348870acfef2..b7e1a3655421 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -142,6 +142,7 @@ struct tegra_i2c_hw_feature { bool has_config_load_reg; int clk_divisor_hs_mode; int clk_divisor_std_fast_mode; + u16 clk_divisor_fast_plus_mode; }; /** @@ -181,6 +182,7 @@ struct tegra_i2c_dev { size_t msg_buf_remaining; int msg_read; u32 bus_clk_rate; + u16 clk_divisor_non_hs_mode; bool is_suspended; }; @@ -441,7 +443,7 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev) /* Make sure clock divisor programmed correctly */ clk_divisor = i2c_dev->hw->clk_divisor_hs_mode; - clk_divisor |= i2c_dev->hw->clk_divisor_std_fast_mode << + clk_divisor |= i2c_dev->clk_divisor_non_hs_mode << I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT; i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR); @@ -703,6 +705,7 @@ static const struct tegra_i2c_hw_feature tegra20_i2c_hw = { .has_single_clk_source = false, .clk_divisor_hs_mode = 3, .clk_divisor_std_fast_mode = 0, + .clk_divisor_fast_plus_mode = 0, .has_config_load_reg = false, }; @@ -712,6 +715,7 @@ static const struct tegra_i2c_hw_feature tegra30_i2c_hw = { .has_single_clk_source = false, .clk_divisor_hs_mode = 3, .clk_divisor_std_fast_mode = 0, + .clk_divisor_fast_plus_mode = 0, .has_config_load_reg = false, }; @@ -721,6 +725,7 @@ static const struct tegra_i2c_hw_feature tegra114_i2c_hw = { .has_single_clk_source = true, .clk_divisor_hs_mode = 1, .clk_divisor_std_fast_mode = 0x19, + .clk_divisor_fast_plus_mode = 0x10, .has_config_load_reg = false, }; @@ -730,6 +735,7 @@ static const struct tegra_i2c_hw_feature tegra124_i2c_hw = { .has_single_clk_source = true, .clk_divisor_hs_mode = 1, .clk_divisor_std_fast_mode = 0x19, + .clk_divisor_fast_plus_mode = 0x10, .has_config_load_reg = true, }; @@ -828,7 +834,14 @@ static int tegra_i2c_probe(struct platform_device *pdev) } } - clk_multiplier *= (i2c_dev->hw->clk_divisor_std_fast_mode + 1); + i2c_dev->clk_divisor_non_hs_mode = + i2c_dev->hw->clk_divisor_std_fast_mode; + if (i2c_dev->hw->clk_divisor_fast_plus_mode && + (i2c_dev->bus_clk_rate == 1000000)) + i2c_dev->clk_divisor_non_hs_mode = + i2c_dev->hw->clk_divisor_fast_plus_mode; + + clk_multiplier *= (i2c_dev->clk_divisor_non_hs_mode + 1); ret = clk_set_rate(i2c_dev->div_clk, i2c_dev->bus_clk_rate * clk_multiplier); if (ret) { -- 2.20.1