diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-imx.c')
-rw-r--r-- | drivers/i2c/busses/i2c-imx.c | 86 |
1 files changed, 63 insertions, 23 deletions
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index 26f83029f64a..b7413655353c 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -194,6 +194,7 @@ struct imx_i2c_dma { struct imx_i2c_struct { struct i2c_adapter adapter; struct clk *clk; + struct notifier_block clk_change_nb; void __iomem *base; wait_queue_head_t queue; unsigned long i2csr; @@ -412,6 +413,19 @@ static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx) dma->chan_using = NULL; } +static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits) +{ + unsigned int temp; + + /* + * i2sr_clr_opcode is the value to clear all interrupts. Here we want to + * clear only <bits>, so we write ~i2sr_clr_opcode with just <bits> + * toggled. This is required because i.MX needs W0C and Vybrid uses W1C. + */ + temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits; + imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); +} + static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy) { unsigned long orig_jiffies = jiffies; @@ -424,8 +438,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy) /* check for arbitration lost */ if (temp & I2SR_IAL) { - temp &= ~I2SR_IAL; - imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); + i2c_imx_clear_irq(i2c_imx, I2SR_IAL); return -EAGAIN; } @@ -452,6 +465,16 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx) dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__); return -ETIMEDOUT; } + + /* check for arbitration lost */ + if (i2c_imx->i2csr & I2SR_IAL) { + dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__); + i2c_imx_clear_irq(i2c_imx, I2SR_IAL); + + i2c_imx->i2csr = 0; + return -EAGAIN; + } + dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__); i2c_imx->i2csr = 0; return 0; @@ -468,15 +491,14 @@ static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx) return 0; } -static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx) +static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx, + unsigned int i2c_clk_rate) { struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div; - unsigned int i2c_clk_rate; unsigned int div; int i; /* Divider value calculation */ - i2c_clk_rate = clk_get_rate(i2c_imx->clk); if (i2c_imx->cur_clk == i2c_clk_rate) return; @@ -511,6 +533,20 @@ static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx) #endif } +static int i2c_imx_clk_notifier_call(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct clk_notifier_data *ndata = data; + struct imx_i2c_struct *i2c_imx = container_of(&ndata->clk, + struct imx_i2c_struct, + clk); + + if (action & POST_RATE_CHANGE) + i2c_imx_set_clk(i2c_imx, ndata->new_rate); + + return NOTIFY_OK; +} + static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) { unsigned int temp = 0; @@ -518,8 +554,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) dev_dbg(&i2c_imx->adapter.dev, "<%s>\n", __func__); - i2c_imx_set_clk(i2c_imx); - imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR); /* Enable I2C controller */ imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR); @@ -583,9 +617,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) if (temp & I2SR_IIF) { /* save status register */ i2c_imx->i2csr = temp; - temp &= ~I2SR_IIF; - temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF); - imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR); + i2c_imx_clear_irq(i2c_imx, I2SR_IIF); wake_up(&i2c_imx->queue); return IRQ_HANDLED; } @@ -1099,14 +1131,6 @@ static int i2c_imx_probe(struct platform_device *pdev) return ret; } - /* Request IRQ */ - ret = devm_request_irq(&pdev->dev, irq, i2c_imx_isr, IRQF_SHARED, - pdev->name, i2c_imx); - if (ret) { - dev_err(&pdev->dev, "can't claim irq %d\n", irq); - goto clk_disable; - } - /* Init queue */ init_waitqueue_head(&i2c_imx->queue); @@ -1125,12 +1149,23 @@ static int i2c_imx_probe(struct platform_device *pdev) if (ret < 0) goto rpm_disable; + /* Request IRQ */ + ret = request_threaded_irq(irq, i2c_imx_isr, NULL, IRQF_SHARED, + pdev->name, i2c_imx); + if (ret) { + dev_err(&pdev->dev, "can't claim irq %d\n", irq); + goto rpm_disable; + } + /* Set up clock divider */ i2c_imx->bitrate = IMX_I2C_BIT_RATE; ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency", &i2c_imx->bitrate); if (ret < 0 && pdata && pdata->bitrate) i2c_imx->bitrate = pdata->bitrate; + i2c_imx->clk_change_nb.notifier_call = i2c_imx_clk_notifier_call; + clk_notifier_register(i2c_imx->clk, &i2c_imx->clk_change_nb); + i2c_imx_set_clk(i2c_imx, clk_get_rate(i2c_imx->clk)); /* Set up chip registers to defaults */ imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN, @@ -1141,12 +1176,12 @@ static int i2c_imx_probe(struct platform_device *pdev) ret = i2c_imx_init_recovery_info(i2c_imx, pdev); /* Give it another chance if pinctrl used is not ready yet */ if (ret == -EPROBE_DEFER) - goto rpm_disable; + goto clk_notifier_unregister; /* Add I2C adapter */ ret = i2c_add_numbered_adapter(&i2c_imx->adapter); if (ret < 0) - goto rpm_disable; + goto clk_notifier_unregister; pm_runtime_mark_last_busy(&pdev->dev); pm_runtime_put_autosuspend(&pdev->dev); @@ -1162,13 +1197,14 @@ static int i2c_imx_probe(struct platform_device *pdev) return 0; /* Return OK */ +clk_notifier_unregister: + clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb); + free_irq(irq, i2c_imx); rpm_disable: pm_runtime_put_noidle(&pdev->dev); pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_dont_use_autosuspend(&pdev->dev); - -clk_disable: clk_disable_unprepare(i2c_imx->clk); return ret; } @@ -1176,7 +1212,7 @@ clk_disable: static int i2c_imx_remove(struct platform_device *pdev) { struct imx_i2c_struct *i2c_imx = platform_get_drvdata(pdev); - int ret; + int irq, ret; ret = pm_runtime_get_sync(&pdev->dev); if (ret < 0) @@ -1195,6 +1231,10 @@ static int i2c_imx_remove(struct platform_device *pdev) imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2CR); imx_i2c_write_reg(0, i2c_imx, IMX_I2C_I2SR); + clk_notifier_unregister(i2c_imx->clk, &i2c_imx->clk_change_nb); + irq = platform_get_irq(pdev, 0); + if (irq >= 0) + free_irq(irq, i2c_imx); clk_disable_unprepare(i2c_imx->clk); pm_runtime_put_noidle(&pdev->dev); |