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i2c: uniphier: add suspend / resume support 

When resuming, set up registers that have been lost in the sleep state.
Also, add clock handling in the resume / suspend hooks.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Masahiro Yamada 2017-07-31 14:53:06 +09:00 committed by Wolfram Sang
parent 8dc0f8c73c
commit 9f9d6a4010
1 changed files with 35 additions and 5 deletions
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40
drivers/i2c/busses/i2c-uniphier.c
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@ -53,6 +53,7 @@ struct uniphier_i2c_priv {
void __iomem *membase;
struct clk *clk;
unsigned int busy_cnt;
unsigned int clk_cycle;
};
static irqreturn_t uniphier_i2c_interrupt(int irq, void *dev_id)
@ -316,13 +317,13 @@ static struct i2c_bus_recovery_info uniphier_i2c_bus_recovery_info = {
.unprepare_recovery = uniphier_i2c_unprepare_recovery,
};
static void uniphier_i2c_hw_init(struct uniphier_i2c_priv *priv,
u32 bus_speed, unsigned long clk_rate)
static void uniphier_i2c_hw_init(struct uniphier_i2c_priv *priv)
{
unsigned int cyc = priv->clk_cycle;
uniphier_i2c_reset(priv, true);
writel((clk_rate / bus_speed / 2 << 16) | (clk_rate / bus_speed),
priv->membase + UNIPHIER_I2C_CLK);
writel((cyc / 2 << 16) | cyc, priv->membase + UNIPHIER_I2C_CLK);
uniphier_i2c_reset(priv, false);
}
@ -376,6 +377,7 @@ static int uniphier_i2c_probe(struct platform_device *pdev)
goto disable_clk;
}
priv->clk_cycle = clk_rate / bus_speed;
init_completion(&priv->comp);
priv->adap.owner = THIS_MODULE;
priv->adap.algo = &uniphier_i2c_algo;
@ -386,7 +388,7 @@ static int uniphier_i2c_probe(struct platform_device *pdev)
i2c_set_adapdata(&priv->adap, priv);
platform_set_drvdata(pdev, priv);
uniphier_i2c_hw_init(priv, bus_speed, clk_rate);
uniphier_i2c_hw_init(priv);
ret = devm_request_irq(dev, irq, uniphier_i2c_interrupt, 0, pdev->name,
priv);
@ -413,6 +415,33 @@ static int uniphier_i2c_remove(struct platform_device *pdev)
return 0;
}
static int __maybe_unused uniphier_i2c_suspend(struct device *dev)
{
struct uniphier_i2c_priv *priv = dev_get_drvdata(dev);
clk_disable_unprepare(priv->clk);
return 0;
}
static int __maybe_unused uniphier_i2c_resume(struct device *dev)
{
struct uniphier_i2c_priv *priv = dev_get_drvdata(dev);
int ret;
ret = clk_prepare_enable(priv->clk);
if (ret)
return ret;
uniphier_i2c_hw_init(priv);
return 0;
}
static const struct dev_pm_ops uniphier_i2c_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(uniphier_i2c_suspend, uniphier_i2c_resume)
};
static const struct of_device_id uniphier_i2c_match[] = {
{ .compatible = "socionext,uniphier-i2c" },
{ /* sentinel */ }
@ -425,6 +454,7 @@ static struct platform_driver uniphier_i2c_drv = {
.driver = {
.name = "uniphier-i2c",
.of_match_table = uniphier_i2c_match,
.pm = &uniphier_i2c_pm_ops,
},
};
module_platform_driver(uniphier_i2c_drv);