From 2a2897bab2d3d50ab466cf908f03b62801f1ff56 Mon Sep 17 00:00:00 2001 From: Laxman Dewangan Date: Sat, 5 Jan 2013 17:34:46 +0530 Subject: i2c: tegra: add support for Tegra114 SoC NVIDIA's Tegra114 has following enhanced feature in i2c controller: - Enable/disable control for per packet transfer complete interrupt. Earlier SoCs could not disable this. - Single clock source for standard/fast and HS mode clock speed. The clock divisor for fast/standard mode is added into the i2c controller to meet the HS and standard/fast mode of clock speed from single source. Add support for the above feature to make it functional on T114 SOCs. Signed-off-by: Laxman Dewangan Reviewed-by: Stephen Warren Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-tegra.c | 77 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 63 insertions(+), 14 deletions(-) (limited to 'drivers/i2c/busses/i2c-tegra.c') diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 7b38877ffec1..2dadb964c464 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -71,6 +71,8 @@ #define I2C_INT_TX_FIFO_DATA_REQ (1<<1) #define I2C_INT_RX_FIFO_DATA_REQ (1<<0) #define I2C_CLK_DIVISOR 0x06c +#define I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT 16 +#define I2C_CLK_MULTIPLIER_STD_FAST_MODE 8 #define DVC_CTRL_REG1 0x000 #define DVC_CTRL_REG1_INTR_EN (1<<10) @@ -117,10 +119,23 @@ enum msg_end_type { /** * struct tegra_i2c_hw_feature : Different HW support on Tegra * @has_continue_xfer_support: Continue transfer supports. + * @has_per_pkt_xfer_complete_irq: Has enable/disable capability for transfer + * complete interrupt per packet basis. + * @has_single_clk_source: The i2c controller has single clock source. Tegra30 + * and earlier Socs has two clock sources i.e. div-clk and + * fast-clk. + * @clk_divisor_hs_mode: Clock divisor in HS mode. + * @clk_divisor_std_fast_mode: Clock divisor in standard/fast mode. It is + * applicable if there is no fast clock source i.e. single clock + * source. */ struct tegra_i2c_hw_feature { bool has_continue_xfer_support; + bool has_per_pkt_xfer_complete_irq; + bool has_single_clk_source; + int clk_divisor_hs_mode; + int clk_divisor_std_fast_mode; }; /** @@ -366,11 +381,13 @@ static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev) static inline int tegra_i2c_clock_enable(struct tegra_i2c_dev *i2c_dev) { int ret; - ret = clk_prepare_enable(i2c_dev->fast_clk); - if (ret < 0) { - dev_err(i2c_dev->dev, - "Enabling fast clk failed, err %d\n", ret); - return ret; + if (!i2c_dev->hw->has_single_clk_source) { + ret = clk_prepare_enable(i2c_dev->fast_clk); + if (ret < 0) { + dev_err(i2c_dev->dev, + "Enabling fast clk failed, err %d\n", ret); + return ret; + } } ret = clk_prepare_enable(i2c_dev->div_clk); if (ret < 0) { @@ -384,13 +401,16 @@ static inline int tegra_i2c_clock_enable(struct tegra_i2c_dev *i2c_dev) static inline void tegra_i2c_clock_disable(struct tegra_i2c_dev *i2c_dev) { clk_disable_unprepare(i2c_dev->div_clk); - clk_disable_unprepare(i2c_dev->fast_clk); + if (!i2c_dev->hw->has_single_clk_source) + clk_disable_unprepare(i2c_dev->fast_clk); } static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev) { u32 val; int err = 0; + int clk_multiplier = I2C_CLK_MULTIPLIER_STD_FAST_MODE; + u32 clk_divisor; tegra_i2c_clock_enable(i2c_dev); @@ -405,7 +425,15 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev) (0x2 << I2C_CNFG_DEBOUNCE_CNT_SHIFT); i2c_writel(i2c_dev, val, I2C_CNFG); i2c_writel(i2c_dev, 0, I2C_INT_MASK); - clk_set_rate(i2c_dev->div_clk, i2c_dev->bus_clk_rate * 8); + + clk_multiplier *= (i2c_dev->hw->clk_divisor_std_fast_mode + 1); + clk_set_rate(i2c_dev->div_clk, i2c_dev->bus_clk_rate * clk_multiplier); + + /* 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 << + I2C_CLK_DIVISOR_STD_FAST_MODE_SHIFT; + i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR); if (!i2c_dev->is_dvc) { u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG); @@ -547,6 +575,8 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, tegra_i2c_fill_tx_fifo(i2c_dev); int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST; + if (i2c_dev->hw->has_per_pkt_xfer_complete_irq) + int_mask |= I2C_INT_PACKET_XFER_COMPLETE; if (msg->flags & I2C_M_RD) int_mask |= I2C_INT_RX_FIFO_DATA_REQ; else if (i2c_dev->msg_buf_remaining) @@ -634,15 +664,32 @@ static const struct i2c_algorithm tegra_i2c_algo = { static const struct tegra_i2c_hw_feature tegra20_i2c_hw = { .has_continue_xfer_support = false, + .has_per_pkt_xfer_complete_irq = false, + .has_single_clk_source = false, + .clk_divisor_hs_mode = 3, + .clk_divisor_std_fast_mode = 0, }; static const struct tegra_i2c_hw_feature tegra30_i2c_hw = { .has_continue_xfer_support = true, + .has_per_pkt_xfer_complete_irq = false, + .has_single_clk_source = false, + .clk_divisor_hs_mode = 3, + .clk_divisor_std_fast_mode = 0, +}; + +static const struct tegra_i2c_hw_feature tegra114_i2c_hw = { + .has_continue_xfer_support = true, + .has_per_pkt_xfer_complete_irq = true, + .has_single_clk_source = true, + .clk_divisor_hs_mode = 1, + .clk_divisor_std_fast_mode = 0x19, }; #if defined(CONFIG_OF) /* Match table for of_platform binding */ static const struct of_device_id tegra_i2c_of_match[] = { + { .compatible = "nvidia,tegra114-i2c", .data = &tegra114_i2c_hw, }, { .compatible = "nvidia,tegra30-i2c", .data = &tegra30_i2c_hw, }, { .compatible = "nvidia,tegra20-i2c", .data = &tegra20_i2c_hw, }, { .compatible = "nvidia,tegra20-i2c-dvc", .data = &tegra20_i2c_hw, }, @@ -688,12 +735,6 @@ static int tegra_i2c_probe(struct platform_device *pdev) return PTR_ERR(div_clk); } - fast_clk = devm_clk_get(&pdev->dev, "fast-clk"); - if (IS_ERR(fast_clk)) { - dev_err(&pdev->dev, "missing bus clock"); - return PTR_ERR(fast_clk); - } - i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL); if (!i2c_dev) { dev_err(&pdev->dev, "Could not allocate struct tegra_i2c_dev"); @@ -702,7 +743,6 @@ static int tegra_i2c_probe(struct platform_device *pdev) i2c_dev->base = base; i2c_dev->div_clk = div_clk; - i2c_dev->fast_clk = fast_clk; i2c_dev->adapter.algo = &tegra_i2c_algo; i2c_dev->irq = irq; i2c_dev->cont_id = pdev->id; @@ -733,6 +773,15 @@ static int tegra_i2c_probe(struct platform_device *pdev) } init_completion(&i2c_dev->msg_complete); + if (!i2c_dev->hw->has_single_clk_source) { + fast_clk = devm_clk_get(&pdev->dev, "fast-clk"); + if (IS_ERR(fast_clk)) { + dev_err(&pdev->dev, "missing fast clock"); + return PTR_ERR(fast_clk); + } + i2c_dev->fast_clk = fast_clk; + } + platform_set_drvdata(pdev, i2c_dev); ret = tegra_i2c_init(i2c_dev); -- cgit v1.2.3