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spi: mxs: implement runtime pm

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This is a straight forward addition of runtime and system sleep pm operations
that handle clk and pinctrl (for runtime pm) and spi_master_{suspend,resume}
(for system sleep).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Uwe Kleine-König 2017-09-27 17:39:22 +02:00 committed by Mark Brown
parent 2bd6bf03f4
commit b7969caf41
1 changed files with 110 additions and 10 deletions
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120
drivers/spi/spi-mxs.c
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@ -44,6 +44,7 @@
#include <linux/completion.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/module.h>
#include <linux/stmp_device.h>
#include <linux/spi/spi.h>
@ -442,6 +443,85 @@ static int mxs_spi_transfer_one(struct spi_master *master,
return status;
}
static int mxs_spi_runtime_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct mxs_spi *spi = spi_master_get_devdata(master);
struct mxs_ssp *ssp = &spi->ssp;
int ret;
clk_disable_unprepare(ssp->clk);
ret = pinctrl_pm_select_idle_state(dev);
if (ret) {
int ret2 = clk_prepare_enable(ssp->clk);
if (ret2)
dev_warn(dev, "Failed to reenable clock after failing pinctrl request (pinctrl: %d, clk: %d)\n",
ret, ret2);
}
return ret;
}
static int mxs_spi_runtime_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
struct mxs_spi *spi = spi_master_get_devdata(master);
struct mxs_ssp *ssp = &spi->ssp;
int ret;
ret = pinctrl_pm_select_default_state(dev);
if (ret)
return ret;
ret = clk_prepare_enable(ssp->clk);
if (ret)
pinctrl_pm_select_idle_state(dev);
return ret;
}
static int __maybe_unused mxs_spi_suspend(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
int ret;
ret = spi_master_suspend(master);
if (ret)
return ret;
if (!pm_runtime_suspended(dev))
return mxs_spi_runtime_suspend(dev);
else
return 0;
}
static int __maybe_unused mxs_spi_resume(struct device *dev)
{
struct spi_master *master = dev_get_drvdata(dev);
int ret;
if (!pm_runtime_suspended(dev))
ret = mxs_spi_runtime_resume(dev);
else
ret = 0;
if (ret)
return ret;
ret = spi_master_resume(master);
if (ret < 0 && !pm_runtime_suspended(dev))
mxs_spi_runtime_suspend(dev);
return ret;
}
static const struct dev_pm_ops mxs_spi_pm = {
SET_RUNTIME_PM_OPS(mxs_spi_runtime_suspend,
mxs_spi_runtime_resume, NULL)
SET_SYSTEM_SLEEP_PM_OPS(mxs_spi_suspend, mxs_spi_resume)
};
static const struct of_device_id mxs_spi_dt_ids[] = {
{ .compatible = "fsl,imx23-spi", .data = (void *) IMX23_SSP, },
{ .compatible = "fsl,imx28-spi", .data = (void *) IMX28_SSP, },
@ -493,12 +573,15 @@ static int mxs_spi_probe(struct platform_device *pdev)
if (!master)
return -ENOMEM;
platform_set_drvdata(pdev, master);
master->transfer_one_message = mxs_spi_transfer_one;
master->bits_per_word_mask = SPI_BPW_MASK(8);
master->mode_bits = SPI_CPOL | SPI_CPHA;
master->num_chipselect = 3;
master->dev.of_node = np;
master->flags = SPI_MASTER_HALF_DUPLEX;
master->auto_runtime_pm = true;
spi = spi_master_get_devdata(master);
ssp = &spi->ssp;
@ -521,28 +604,41 @@ static int mxs_spi_probe(struct platform_device *pdev)
goto out_master_free;
}
ret = clk_prepare_enable(ssp->clk);
if (ret)
goto out_dma_release;
pm_runtime_enable(ssp->dev);
if (!pm_runtime_enabled(ssp->dev)) {
ret = mxs_spi_runtime_resume(ssp->dev);
if (ret < 0) {
dev_err(ssp->dev, "runtime resume failed\n");
goto out_dma_release;
}
}
ret = pm_runtime_get_sync(ssp->dev);
if (ret < 0) {
dev_err(ssp->dev, "runtime_get_sync failed\n");
goto out_pm_runtime_disable;
}
clk_set_rate(ssp->clk, clk_freq);
ret = stmp_reset_block(ssp->base);
if (ret)
goto out_disable_clk;
platform_set_drvdata(pdev, master);
goto out_pm_runtime_put;
ret = devm_spi_register_master(&pdev->dev, master);
if (ret) {
dev_err(&pdev->dev, "Cannot register SPI master, %d\n", ret);
goto out_disable_clk;
goto out_pm_runtime_put;
}
pm_runtime_put(ssp->dev);
return 0;
out_disable_clk:
clk_disable_unprepare(ssp->clk);
out_pm_runtime_put:
pm_runtime_put(ssp->dev);
out_pm_runtime_disable:
pm_runtime_disable(ssp->dev);
out_dma_release:
dma_release_channel(ssp->dmach);
out_master_free:
@ -560,7 +656,10 @@ static int mxs_spi_remove(struct platform_device *pdev)
spi = spi_master_get_devdata(master);
ssp = &spi->ssp;
clk_disable_unprepare(ssp->clk);
pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
mxs_spi_runtime_suspend(&pdev->dev);
dma_release_channel(ssp->dmach);
return 0;
@ -572,6 +671,7 @@ static struct platform_driver mxs_spi_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = mxs_spi_dt_ids,
.pm = &mxs_spi_pm,
},
};