diff options
| -rw-r--r-- | drivers/i2c/busses/i2c-tegra.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c index 79c6aa87499b..a46446dbc48a 100644 --- a/drivers/i2c/busses/i2c-tegra.c +++ b/drivers/i2c/busses/i2c-tegra.c @@ -51,6 +51,7 @@ #define I2C_FIFO_STATUS_RX_SHIFT 0 #define I2C_INT_MASK 0x064 #define I2C_INT_STATUS 0x068 +#define I2C_INT_BUS_CLR_DONE BIT(11) #define I2C_INT_PACKET_XFER_COMPLETE BIT(7) #define I2C_INT_ALL_PACKETS_XFER_COMPLETE BIT(6) #define I2C_INT_TX_FIFO_OVERFLOW BIT(5) @@ -93,6 +94,15 @@ #define I2C_HEADER_MASTER_ADDR_SHIFT 12 #define I2C_HEADER_SLAVE_ADDR_SHIFT 1 +#define I2C_BUS_CLEAR_CNFG 0x084 +#define I2C_BC_SCLK_THRESHOLD 9 +#define I2C_BC_SCLK_THRESHOLD_SHIFT 16 +#define I2C_BC_STOP_COND BIT(2) +#define I2C_BC_TERMINATE BIT(1) +#define I2C_BC_ENABLE BIT(0) +#define I2C_BUS_CLEAR_STATUS 0x088 +#define I2C_BC_STATUS BIT(0) + #define I2C_CONFIG_LOAD 0x08C #define I2C_MSTR_CONFIG_LOAD BIT(0) #define I2C_SLV_CONFIG_LOAD BIT(1) @@ -154,6 +164,8 @@ enum msg_end_type { * be transferred in one go. * @quirks: i2c adapter quirks for limiting write/read transfer size and not * allowing 0 length transfers. + * @supports_bus_clear: Bus Clear support to recover from bus hang during + * SDA stuck low from device for some unknown reasons. */ struct tegra_i2c_hw_feature { bool has_continue_xfer_support; @@ -167,6 +179,7 @@ struct tegra_i2c_hw_feature { bool has_slcg_override_reg; bool has_mst_fifo; const struct i2c_adapter_quirks *quirks; + bool supports_bus_clear; }; /** @@ -640,6 +653,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id) goto err; } + /* + * I2C transfer is terminated during the bus clear so skip + * processing the other interrupts. + */ + if (i2c_dev->hw->supports_bus_clear && (status & I2C_INT_BUS_CLR_DONE)) + goto err; + if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) { if (i2c_dev->msg_buf_remaining) tegra_i2c_empty_rx_fifo(i2c_dev); @@ -668,6 +688,8 @@ err: tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST | I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ | I2C_INT_RX_FIFO_DATA_REQ); + if (i2c_dev->hw->supports_bus_clear) + tegra_i2c_mask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE); i2c_writel(i2c_dev, status, I2C_INT_STATUS); if (i2c_dev->is_dvc) dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS); @@ -678,6 +700,44 @@ done: return IRQ_HANDLED; } +static int tegra_i2c_issue_bus_clear(struct i2c_adapter *adap) +{ + struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap); + int err; + unsigned long time_left; + u32 reg; + + reinit_completion(&i2c_dev->msg_complete); + reg = (I2C_BC_SCLK_THRESHOLD << I2C_BC_SCLK_THRESHOLD_SHIFT) | + I2C_BC_STOP_COND | I2C_BC_TERMINATE; + i2c_writel(i2c_dev, reg, I2C_BUS_CLEAR_CNFG); + if (i2c_dev->hw->has_config_load_reg) { + err = tegra_i2c_wait_for_config_load(i2c_dev); + if (err) + return err; + } + + reg |= I2C_BC_ENABLE; + i2c_writel(i2c_dev, reg, I2C_BUS_CLEAR_CNFG); + tegra_i2c_unmask_irq(i2c_dev, I2C_INT_BUS_CLR_DONE); + + time_left = wait_for_completion_timeout(&i2c_dev->msg_complete, + TEGRA_I2C_TIMEOUT); + if (time_left == 0) { + dev_err(i2c_dev->dev, "timed out for bus clear\n"); + return -ETIMEDOUT; + } + + reg = i2c_readl(i2c_dev, I2C_BUS_CLEAR_STATUS); + if (!(reg & I2C_BC_STATUS)) { + dev_err(i2c_dev->dev, + "un-recovered arbitration lost\n"); + return -EIO; + } + + return -EAGAIN; +} + static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, struct i2c_msg *msg, enum msg_end_type end_state) { @@ -759,6 +819,13 @@ static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev, return 0; tegra_i2c_init(i2c_dev); + /* start recovery upon arbitration loss in single master mode */ + if (i2c_dev->msg_err == I2C_ERR_ARBITRATION_LOST) { + if (!i2c_dev->is_multimaster_mode) + return i2c_recover_bus(&i2c_dev->adapter); + return -EAGAIN; + } + if (i2c_dev->msg_err == I2C_ERR_NO_ACK) { if (msg->flags & I2C_M_IGNORE_NAK) return 0; @@ -841,6 +908,10 @@ static const struct i2c_adapter_quirks tegra194_i2c_quirks = { .flags = I2C_AQ_NO_ZERO_LEN, }; +static struct i2c_bus_recovery_info tegra_i2c_recovery_info = { + .recover_bus = tegra_i2c_issue_bus_clear, +}; + static const struct tegra_i2c_hw_feature tegra20_i2c_hw = { .has_continue_xfer_support = false, .has_per_pkt_xfer_complete_irq = false, @@ -853,6 +924,7 @@ static const struct tegra_i2c_hw_feature tegra20_i2c_hw = { .has_slcg_override_reg = false, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, + .supports_bus_clear = false, }; static const struct tegra_i2c_hw_feature tegra30_i2c_hw = { @@ -867,6 +939,7 @@ static const struct tegra_i2c_hw_feature tegra30_i2c_hw = { .has_slcg_override_reg = false, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, + .supports_bus_clear = false, }; static const struct tegra_i2c_hw_feature tegra114_i2c_hw = { @@ -881,6 +954,7 @@ static const struct tegra_i2c_hw_feature tegra114_i2c_hw = { .has_slcg_override_reg = false, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, + .supports_bus_clear = true, }; static const struct tegra_i2c_hw_feature tegra124_i2c_hw = { @@ -895,6 +969,7 @@ static const struct tegra_i2c_hw_feature tegra124_i2c_hw = { .has_slcg_override_reg = true, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, + .supports_bus_clear = true, }; static const struct tegra_i2c_hw_feature tegra210_i2c_hw = { @@ -909,6 +984,7 @@ static const struct tegra_i2c_hw_feature tegra210_i2c_hw = { .has_slcg_override_reg = true, .has_mst_fifo = false, .quirks = &tegra_i2c_quirks, + .supports_bus_clear = true, }; static const struct tegra_i2c_hw_feature tegra194_i2c_hw = { @@ -923,6 +999,7 @@ static const struct tegra_i2c_hw_feature tegra194_i2c_hw = { .has_slcg_override_reg = true, .has_mst_fifo = true, .quirks = &tegra194_i2c_quirks, + .supports_bus_clear = true, }; /* Match table for of_platform binding */ @@ -974,6 +1051,7 @@ static int tegra_i2c_probe(struct platform_device *pdev) i2c_dev->base = base; i2c_dev->div_clk = div_clk; i2c_dev->adapter.algo = &tegra_i2c_algo; + i2c_dev->adapter.retries = 1; i2c_dev->irq = irq; i2c_dev->cont_id = pdev->id; i2c_dev->dev = &pdev->dev; @@ -1051,6 +1129,9 @@ static int tegra_i2c_probe(struct platform_device *pdev) } } + if (i2c_dev->hw->supports_bus_clear) + i2c_dev->adapter.bus_recovery_info = &tegra_i2c_recovery_info; + ret = tegra_i2c_init(i2c_dev); if (ret) { dev_err(&pdev->dev, "Failed to initialize i2c controller\n"); |