66AK2G has I2C instances that are not apart of the ALWAYS_ON power domain unlike other Keystone 2 SoCs and OMAPL138. Therefore, pm_runtime is required to insure the power domain used by the specific I2C instance is properly turned on along with its functional clock. Signed-off-by: Franklin S Cooper Jr <fcooper@xxxxxx> --- Version 4 changes: Fix wording on error message Fix additional error path Version 3 changes: Remove several statements that set clk to NULL Fix error path drivers/i2c/busses/i2c-davinci.c | 67 +++++++++++++++++++++++++++++++++------- 1 file changed, 55 insertions(+), 12 deletions(-) diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c index b8c4353..a2d9f7c 100644 --- a/drivers/i2c/busses/i2c-davinci.c +++ b/drivers/i2c/busses/i2c-davinci.c @@ -36,6 +36,7 @@ #include <linux/gpio.h> #include <linux/of_device.h> #include <linux/platform_data/i2c-davinci.h> +#include <linux/pm_runtime.h> /* ----- global defines ----------------------------------------------- */ @@ -122,6 +123,9 @@ /* set the SDA GPIO low */ #define DAVINCI_I2C_DCLR_PDCLR1 BIT(1) +/* timeout for pm runtime autosuspend */ +#define DAVINCI_I2C_PM_TIMEOUT 1000 /* ms */ + struct davinci_i2c_dev { struct device *dev; void __iomem *base; @@ -541,10 +545,17 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num); + ret = pm_runtime_get_sync(dev->dev); + if (ret < 0) { + dev_err(dev->dev, "Failed to runtime_get device: %d\n", ret); + pm_runtime_put_noidle(dev->dev); + return ret; + } + ret = i2c_davinci_wait_bus_not_busy(dev); if (ret < 0) { dev_warn(dev->dev, "timeout waiting for bus ready\n"); - return ret; + goto out; } for (i = 0; i < num; i++) { @@ -552,14 +563,19 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) dev_dbg(dev->dev, "%s [%d/%d] ret: %d\n", __func__, i + 1, num, ret); if (ret < 0) - return ret; + goto out; } + ret = num; #ifdef CONFIG_CPU_FREQ complete(&dev->xfr_complete); #endif - return num; +out: + pm_runtime_mark_last_busy(dev->dev); + pm_runtime_put_autosuspend(dev->dev); + + return ret; } static u32 i2c_davinci_func(struct i2c_adapter *adap) @@ -599,6 +615,9 @@ static irqreturn_t i2c_davinci_isr(int this_irq, void *dev_id) int count = 0; u16 w; + if (pm_runtime_suspended(dev->dev)) + return IRQ_NONE; + while ((stat = davinci_i2c_read_reg(dev, DAVINCI_I2C_IVR_REG))) { dev_dbg(dev->dev, "%s: stat=0x%x\n", __func__, stat); if (count++ == 100) { @@ -802,13 +821,24 @@ static int davinci_i2c_probe(struct platform_device *pdev) dev->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(dev->clk)) return PTR_ERR(dev->clk); - clk_prepare_enable(dev->clk); mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); dev->base = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(dev->base)) { - r = PTR_ERR(dev->base); - goto err_unuse_clocks; + return PTR_ERR(dev->base); + } + + pm_runtime_set_autosuspend_delay(dev->dev, + DAVINCI_I2C_PM_TIMEOUT); + pm_runtime_use_autosuspend(dev->dev); + + pm_runtime_enable(dev->dev); + + r = pm_runtime_get_sync(dev->dev); + if (r < 0) { + dev_err(dev->dev, "failed to runtime_get device: %d\n", r); + pm_runtime_put_noidle(dev->dev); + return r; } i2c_davinci_init(dev); @@ -849,27 +879,40 @@ static int davinci_i2c_probe(struct platform_device *pdev) if (r) goto err_unuse_clocks; + pm_runtime_mark_last_busy(dev->dev); + pm_runtime_put_autosuspend(dev->dev); + return 0; err_unuse_clocks: - clk_disable_unprepare(dev->clk); - dev->clk = NULL; + pm_runtime_dont_use_autosuspend(dev->dev); + pm_runtime_put_sync(dev->dev); + pm_runtime_disable(dev->dev); + return r; } static int davinci_i2c_remove(struct platform_device *pdev) { struct davinci_i2c_dev *dev = platform_get_drvdata(pdev); + int ret; i2c_davinci_cpufreq_deregister(dev); i2c_del_adapter(&dev->adapter); - clk_disable_unprepare(dev->clk); - dev->clk = NULL; + ret = pm_runtime_get_sync(&pdev->dev); + if (ret < 0) { + pm_runtime_put_noidle(&pdev->dev); + return ret; + } davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, 0); + pm_runtime_dont_use_autosuspend(dev->dev); + pm_runtime_put_sync(dev->dev); + pm_runtime_disable(dev->dev); + return 0; } @@ -880,7 +923,6 @@ static int davinci_i2c_suspend(struct device *dev) /* put I2C into reset */ davinci_i2c_reset_ctrl(i2c_dev, 0); - clk_disable_unprepare(i2c_dev->clk); return 0; } @@ -889,7 +931,6 @@ static int davinci_i2c_resume(struct device *dev) { struct davinci_i2c_dev *i2c_dev = dev_get_drvdata(dev); - clk_prepare_enable(i2c_dev->clk); /* take I2C out of reset */ davinci_i2c_reset_ctrl(i2c_dev, 1); @@ -899,6 +940,8 @@ static int davinci_i2c_resume(struct device *dev) static const struct dev_pm_ops davinci_i2c_pm = { .suspend = davinci_i2c_suspend, .resume = davinci_i2c_resume, + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) }; #define davinci_i2c_pm_ops (&davinci_i2c_pm) -- 2.9.4.dirty