On Thu, Oct 15, 2015 at 05:56:55PM +0530, Shubhrajyoti Datta wrote:
> Currently the clocks are enabled at probe and disabled at remove.
> Which keeps the clocks enabled even if no transaction is going on.
> This patch enables the clocks at the start of transfer and disables
> after it.
>
> Also adapts to runtime pm.
> Remove xi2c->suspended and use pm runtime status instead.
>
> converts dev pm to const to silence a checkpatch warning.
>
> Signed-off-by: Shubhrajyoti Datta <shubhraj@xxxxxxxxxx>
Can you resend please with the driver maintainers in cc? Best use
get_maintainer.pl to create the CC list. Thanks!
> ---
> drivers/i2c/busses/i2c-cadence.c | 73 ++++++++++++++++++++++++--------------
> 1 files changed, 46 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
> index 84deed6..6b08d16 100644
> --- a/drivers/i2c/busses/i2c-cadence.c
> +++ b/drivers/i2c/busses/i2c-cadence.c
> @@ -18,6 +18,7 @@
> #include <linux/module.h>
> #include <linux/platform_device.h>
> #include <linux/of.h>
> +#include <linux/pm_runtime.h>
>
> /* Register offsets for the I2C device. */
> #define CDNS_I2C_CR_OFFSET 0x00 /* Control Register, RW */
> @@ -96,6 +97,8 @@
> CDNS_I2C_IXR_COMP)
>
> #define CDNS_I2C_TIMEOUT msecs_to_jiffies(1000)
> +/* timeout for pm runtime autosuspend */
> +#define CNDS_I2C_PM_TIMEOUT 1000 /* ms */
>
> #define CDNS_I2C_FIFO_DEPTH 16
> /* FIFO depth at which the DATA interrupt occurs */
> @@ -128,7 +131,6 @@
> * @xfer_done: Transfer complete status
> * @p_send_buf: Pointer to transmit buffer
> * @p_recv_buf: Pointer to receive buffer
> - * @suspended: Flag holding the device's PM status
> * @send_count: Number of bytes still expected to send
> * @recv_count: Number of bytes still expected to receive
> * @curr_recv_count: Number of bytes to be received in current transfer
> @@ -141,6 +143,7 @@
> * @quirks: flag for broken hold bit usage in r1p10
> */
> struct cdns_i2c {
> + struct device *dev;
> void __iomem *membase;
> struct i2c_adapter adap;
> struct i2c_msg *p_msg;
> @@ -148,7 +151,6 @@ struct cdns_i2c {
> struct completion xfer_done;
> unsigned char *p_send_buf;
> unsigned char *p_recv_buf;
> - u8 suspended;
> unsigned int send_count;
> unsigned int recv_count;
> unsigned int curr_recv_count;
> @@ -569,9 +571,14 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> struct cdns_i2c *id = adap->algo_data;
> bool hold_quirk;
>
> + ret = pm_runtime_get_sync(id->dev);
> + if (ret < 0)
> + return ret;
> /* Check if the bus is free */
> - if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA)
> - return -EAGAIN;
> + if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA) {
> + ret = -EAGAIN;
> + goto out;
> + }
>
> hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT);
> /*
> @@ -590,7 +597,8 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> if (msgs[count].flags & I2C_M_RD) {
> dev_warn(adap->dev.parent,
> "Can't do repeated start after a receive message\n");
> - return -EOPNOTSUPP;
> + ret = -EOPNOTSUPP;
> + goto out;
> }
> }
> id->bus_hold_flag = 1;
> @@ -608,20 +616,26 @@ static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
>
> ret = cdns_i2c_process_msg(id, msgs, adap);
> if (ret)
> - return ret;
> + goto out;
>
> /* Report the other error interrupts to application */
> if (id->err_status) {
> cdns_i2c_master_reset(adap);
>
> - if (id->err_status & CDNS_I2C_IXR_NACK)
> - return -ENXIO;
> -
> - return -EIO;
> + if (id->err_status & CDNS_I2C_IXR_NACK) {
> + ret = -ENXIO;
> + goto out;
> + }
> + ret = -EIO;
> + goto out;
> }
> }
>
> - return num;
> + ret = num;
> +out:
> + pm_runtime_mark_last_busy(id->dev);
> + pm_runtime_put_autosuspend(id->dev);
> + return ret;
> }
>
> /**
> @@ -760,7 +774,7 @@ static int cdns_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
> struct clk_notifier_data *ndata = data;
> struct cdns_i2c *id = to_cdns_i2c(nb);
>
> - if (id->suspended)
> + if (pm_runtime_suspended(id->dev))
> return NOTIFY_OK;
>
> switch (event) {
> @@ -808,14 +822,12 @@ static int cdns_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
> *
> * Return: 0 always
> */
> -static int __maybe_unused cdns_i2c_suspend(struct device *_dev)
> +static int __maybe_unused cdns_i2c_runtime_suspend(struct device *dev)
> {
> - struct platform_device *pdev = container_of(_dev,
> - struct platform_device, dev);
> + struct platform_device *pdev = to_platform_device(dev);
> struct cdns_i2c *xi2c = platform_get_drvdata(pdev);
>
> clk_disable(xi2c->clk);
> - xi2c->suspended = 1;
>
> return 0;
> }
> @@ -828,26 +840,25 @@ static int __maybe_unused cdns_i2c_suspend(struct device *_dev)
> *
> * Return: 0 on success and error value on error
> */
> -static int __maybe_unused cdns_i2c_resume(struct device *_dev)
> +static int __maybe_unused cdns_i2c_runtime_resume(struct device *dev)
> {
> - struct platform_device *pdev = container_of(_dev,
> - struct platform_device, dev);
> + struct platform_device *pdev = to_platform_device(dev);
> struct cdns_i2c *xi2c = platform_get_drvdata(pdev);
> int ret;
>
> ret = clk_enable(xi2c->clk);
> if (ret) {
> - dev_err(_dev, "Cannot enable clock.\n");
> + dev_err(dev, "Cannot enable clock.\n");
> return ret;
> }
>
> - xi2c->suspended = 0;
> -
> return 0;
> }
>
> -static SIMPLE_DEV_PM_OPS(cdns_i2c_dev_pm_ops, cdns_i2c_suspend,
> - cdns_i2c_resume);
> +static const struct dev_pm_ops cdns_i2c_dev_pm_ops = {
> + SET_RUNTIME_PM_OPS(cdns_i2c_runtime_suspend,
> + cdns_i2c_runtime_resume, NULL)
> +};
>
> static const struct cdns_platform_data r1p10_i2c_def = {
> .quirks = CDNS_I2C_BROKEN_HOLD_BIT,
> @@ -881,6 +892,7 @@ static int cdns_i2c_probe(struct platform_device *pdev)
> if (!id)
> return -ENOMEM;
>
> + id->dev = &pdev->dev;
> platform_set_drvdata(pdev, id);
>
> match = of_match_node(cdns_i2c_of_match, pdev->dev.of_node);
> @@ -913,10 +925,14 @@ static int cdns_i2c_probe(struct platform_device *pdev)
> return PTR_ERR(id->clk);
> }
> ret = clk_prepare_enable(id->clk);
> - if (ret) {
> + if (ret)
> dev_err(&pdev->dev, "Unable to enable clock.\n");
> - return ret;
> - }
> +
> + pm_runtime_enable(id->dev);
> + pm_runtime_set_autosuspend_delay(id->dev, CNDS_I2C_PM_TIMEOUT);
> + pm_runtime_use_autosuspend(id->dev);
> + pm_runtime_set_active(id->dev);
> +
> id->clk_rate_change_nb.notifier_call = cdns_i2c_clk_notifier_cb;
> if (clk_notifier_register(id->clk, &id->clk_rate_change_nb))
> dev_warn(&pdev->dev, "Unable to register clock notifier.\n");
> @@ -966,6 +982,8 @@ static int cdns_i2c_probe(struct platform_device *pdev)
>
> err_clk_dis:
> clk_disable_unprepare(id->clk);
> + pm_runtime_set_suspended(&pdev->dev);
> + pm_runtime_disable(&pdev->dev);
> return ret;
> }
>
> @@ -984,6 +1002,7 @@ static int cdns_i2c_remove(struct platform_device *pdev)
> i2c_del_adapter(&id->adap);
> clk_notifier_unregister(id->clk, &id->clk_rate_change_nb);
> clk_disable_unprepare(id->clk);
> + pm_runtime_disable(&pdev->dev);
>
> return 0;
> }
> --
> 1.7.1
>
> --
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