Hello,
> On Sun, Jan 03, 2021 at 04:51:46AM -0600, Samuel Holland wrote:
>> To save power, gate the clock when the bus is inactive, during system
>> sleep, and during shutdown. On some platforms, specifically Allwinner
>> A13/A20, gating the clock implicitly resets the module as well. Since
>> the module already needs to be reset after some suspend/resume cycles,
>> it is simple enough to reset it during every runtime suspend/resume.
>>
>> Because the bus may be used by wakeup source IRQ threads, it needs to
>> be functional as soon as IRQs are enabled. Thus, its system PM hooks
>> need to run in the noirq phase.
>>
>> Signed-off-by: Samuel Holland <[email protected]>
>
> Gregory, what do you think?
I didn't have the opportunity to test it on Marvell platform, but I
don't want to hold this patch, so let's merge it.
Gregory
>
>> ---
>> drivers/i2c/busses/i2c-mv64xxx.c | 120 ++++++++++++++++++++-----------
>> 1 file changed, 78 insertions(+), 42 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-mv64xxx.c
>> b/drivers/i2c/busses/i2c-mv64xxx.c
>> index 5cfe70aedced..b03c344323d1 100644
>> --- a/drivers/i2c/busses/i2c-mv64xxx.c
>> +++ b/drivers/i2c/busses/i2c-mv64xxx.c
>> @@ -18,6 +18,7 @@
>> #include <linux/mv643xx_i2c.h>
>> #include <linux/platform_device.h>
>> #include <linux/pinctrl/consumer.h>
>> +#include <linux/pm_runtime.h>
>> #include <linux/reset.h>
>> #include <linux/io.h>
>> #include <linux/of.h>
>> @@ -717,6 +718,10 @@ mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct
>> i2c_msg msgs[], int num)
>> struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
>> int rc, ret = num;
>>
>> + rc = pm_runtime_resume_and_get(&adap->dev);
>> + if (rc)
>> + return rc;
>> +
>> BUG_ON(drv_data->msgs != NULL);
>> drv_data->msgs = msgs;
>> drv_data->num_msgs = num;
>> @@ -732,6 +737,9 @@ mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct
>> i2c_msg msgs[], int num)
>> drv_data->num_msgs = 0;
>> drv_data->msgs = NULL;
>>
>> + pm_runtime_mark_last_busy(&adap->dev);
>> + pm_runtime_put_autosuspend(&adap->dev);
>> +
>> return ret;
>> }
>>
>> @@ -828,7 +836,6 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
>> rc = PTR_ERR(drv_data->rstc);
>> goto out;
>> }
>> - reset_control_deassert(drv_data->rstc);
>>
>> /* Its not yet defined how timeouts will be specified in device tree.
>> * So hard code the value to 1 second.
>> @@ -893,6 +900,32 @@ static int mv64xxx_i2c_init_recovery_info(struct
>> mv64xxx_i2c_data *drv_data,
>> return 0;
>> }
>>
>> +static int
>> +mv64xxx_i2c_runtime_suspend(struct device *dev)
>> +{
>> + struct mv64xxx_i2c_data *drv_data = dev_get_drvdata(dev);
>> +
>> + reset_control_assert(drv_data->rstc);
>> + clk_disable_unprepare(drv_data->reg_clk);
>> + clk_disable_unprepare(drv_data->clk);
>> +
>> + return 0;
>> +}
>> +
>> +static int
>> +mv64xxx_i2c_runtime_resume(struct device *dev)
>> +{
>> + struct mv64xxx_i2c_data *drv_data = dev_get_drvdata(dev);
>> +
>> + clk_prepare_enable(drv_data->clk);
>> + clk_prepare_enable(drv_data->reg_clk);
>> + reset_control_reset(drv_data->rstc);
>> +
>> + mv64xxx_i2c_hw_init(drv_data);
>> +
>> + return 0;
>> +}
>> +
>> static int
>> mv64xxx_i2c_probe(struct platform_device *pd)
>> {
>> @@ -920,18 +953,22 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>>
>> /* Not all platforms have clocks */
>> drv_data->clk = devm_clk_get(&pd->dev, NULL);
>> - if (PTR_ERR(drv_data->clk) == -EPROBE_DEFER)
>> - return -EPROBE_DEFER;
>> - if (!IS_ERR(drv_data->clk))
>> - clk_prepare_enable(drv_data->clk);
>> + if (IS_ERR(drv_data->clk)) {
>> + if (PTR_ERR(drv_data->clk) == -EPROBE_DEFER)
>> + return -EPROBE_DEFER;
>> + drv_data->clk = NULL;
>> + }
>>
>> drv_data->reg_clk = devm_clk_get(&pd->dev, "reg");
>> - if (PTR_ERR(drv_data->reg_clk) == -EPROBE_DEFER)
>> - return -EPROBE_DEFER;
>> - if (!IS_ERR(drv_data->reg_clk))
>> - clk_prepare_enable(drv_data->reg_clk);
>> + if (IS_ERR(drv_data->reg_clk)) {
>> + if (PTR_ERR(drv_data->reg_clk) == -EPROBE_DEFER)
>> + return -EPROBE_DEFER;
>> + drv_data->reg_clk = NULL;
>> + }
>>
>> drv_data->irq = platform_get_irq(pd, 0);
>> + if (drv_data->irq < 0)
>> + return drv_data->irq;
>>
>> if (pdata) {
>> drv_data->freq_m = pdata->freq_m;
>> @@ -942,16 +979,12 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>> } else if (pd->dev.of_node) {
>> rc = mv64xxx_of_config(drv_data, &pd->dev);
>> if (rc)
>> - goto exit_clk;
>> - }
>> - if (drv_data->irq < 0) {
>> - rc = drv_data->irq;
>> - goto exit_reset;
>> + return rc;
>> }
>>
>> rc = mv64xxx_i2c_init_recovery_info(drv_data, &pd->dev);
>> if (rc == -EPROBE_DEFER)
>> - goto exit_reset;
>> + return rc;
>>
>> drv_data->adapter.dev.parent = &pd->dev;
>> drv_data->adapter.algo = &mv64xxx_i2c_algo;
>> @@ -962,7 +995,14 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>> platform_set_drvdata(pd, drv_data);
>> i2c_set_adapdata(&drv_data->adapter, drv_data);
>>
>> - mv64xxx_i2c_hw_init(drv_data);
>> + pm_runtime_set_autosuspend_delay(&pd->dev, MSEC_PER_SEC);
>> + pm_runtime_use_autosuspend(&pd->dev);
>> + pm_runtime_enable(&pd->dev);
>> + if (!pm_runtime_enabled(&pd->dev)) {
>> + rc = mv64xxx_i2c_runtime_resume(&pd->dev);
>> + if (rc)
>> + goto exit_disable_pm;
>> + }
>>
>> rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
>> MV64XXX_I2C_CTLR_NAME, drv_data);
>> @@ -970,7 +1010,7 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>> dev_err(&drv_data->adapter.dev,
>> "mv64xxx: Can't register intr handler irq%d: %d\n",
>> drv_data->irq, rc);
>> - goto exit_reset;
>> + goto exit_disable_pm;
>> } else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
>> dev_err(&drv_data->adapter.dev,
>> "mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
>> @@ -981,54 +1021,50 @@ mv64xxx_i2c_probe(struct platform_device *pd)
>>
>> exit_free_irq:
>> free_irq(drv_data->irq, drv_data);
>> -exit_reset:
>> - reset_control_assert(drv_data->rstc);
>> -exit_clk:
>> - clk_disable_unprepare(drv_data->reg_clk);
>> - clk_disable_unprepare(drv_data->clk);
>> +exit_disable_pm:
>> + pm_runtime_disable(&pd->dev);
>> + if (!pm_runtime_status_suspended(&pd->dev))
>> + mv64xxx_i2c_runtime_suspend(&pd->dev);
>>
>> return rc;
>> }
>>
>> static int
>> -mv64xxx_i2c_remove(struct platform_device *dev)
>> +mv64xxx_i2c_remove(struct platform_device *pd)
>> {
>> - struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev);
>> + struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(pd);
>>
>> i2c_del_adapter(&drv_data->adapter);
>> free_irq(drv_data->irq, drv_data);
>> - reset_control_assert(drv_data->rstc);
>> - clk_disable_unprepare(drv_data->reg_clk);
>> - clk_disable_unprepare(drv_data->clk);
>> + pm_runtime_disable(&pd->dev);
>> + if (!pm_runtime_status_suspended(&pd->dev))
>> + mv64xxx_i2c_runtime_suspend(&pd->dev);
>>
>> return 0;
>> }
>>
>> -#ifdef CONFIG_PM
>> -static int mv64xxx_i2c_resume(struct device *dev)
>> +static void
>> +mv64xxx_i2c_shutdown(struct platform_device *pd)
>> {
>> - struct mv64xxx_i2c_data *drv_data = dev_get_drvdata(dev);
>> -
>> - mv64xxx_i2c_hw_init(drv_data);
>> -
>> - return 0;
>> + pm_runtime_disable(&pd->dev);
>> + if (!pm_runtime_status_suspended(&pd->dev))
>> + mv64xxx_i2c_runtime_suspend(&pd->dev);
>> }
>>
>> -static const struct dev_pm_ops mv64xxx_i2c_pm = {
>> - .resume = mv64xxx_i2c_resume,
>> +static const struct dev_pm_ops mv64xxx_i2c_pm_ops = {
>> + SET_RUNTIME_PM_OPS(mv64xxx_i2c_runtime_suspend,
>> + mv64xxx_i2c_runtime_resume, NULL)
>> + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
>> + pm_runtime_force_resume)
>> };
>>
>> -#define mv64xxx_i2c_pm_ops (&mv64xxx_i2c_pm)
>> -#else
>> -#define mv64xxx_i2c_pm_ops NULL
>> -#endif
>> -
>> static struct platform_driver mv64xxx_i2c_driver = {
>> .probe = mv64xxx_i2c_probe,
>> .remove = mv64xxx_i2c_remove,
>> + .shutdown = mv64xxx_i2c_shutdown,
>> .driver = {
>> .name = MV64XXX_I2C_CTLR_NAME,
>> - .pm = mv64xxx_i2c_pm_ops,
>> + .pm = &mv64xxx_i2c_pm_ops,
>> .of_match_table = mv64xxx_i2c_of_match_table,
>> },
>> };
>> --
>> 2.26.2
>>
--
Gregory Clement, Bootlin
Embedded Linux and Kernel engineering
http://bootlin.com
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