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i2c: riic: Add Runtime PM support 

- Replace explicit clock handling by Runtime PM calls,
  - Streamline Runtime PM handling in error paths,
  - Enable Runtime PM in .probe(),
  - Disable Runtime PM in .remove(),
  - Make sure the device is runtime-resumed when disabling interrupts in
    .remove().

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
hifive-unleashed-5.2
Geert Uytterhoeven 2019-03-20 11:30:03 +01:00 committed by Wolfram Sang
parent 18073da769
commit d303ce595c
1 changed files with 24 additions and 19 deletions
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43
drivers/i2c/busses/i2c-riic.c
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@ -43,6 +43,7 @@
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#define RIIC_ICCR1 0x00
#define RIIC_ICCR2 0x04
@ -112,12 +113,10 @@ static int riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
{
struct riic_dev *riic = i2c_get_adapdata(adap);
unsigned long time_left;
int i, ret;
int i;
u8 start_bit;
ret = clk_prepare_enable(riic->clk);
if (ret)
return ret;
pm_runtime_get_sync(adap->dev.parent);
if (readb(riic->base + RIIC_ICCR2) & ICCR2_BBSY) {
riic->err = -EBUSY;
@ -150,7 +149,7 @@ static int riic_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
}
out:
clk_disable_unprepare(riic->clk);
pm_runtime_put(adap->dev.parent);
return riic->err ?: num;
}
@ -281,20 +280,18 @@ static const struct i2c_algorithm riic_algo = {
static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
{
int ret;
int ret = 0;
unsigned long rate;
int total_ticks, cks, brl, brh;
ret = clk_prepare_enable(riic->clk);
if (ret)
return ret;
pm_runtime_get_sync(riic->adapter.dev.parent);
if (t->bus_freq_hz > 400000) {
dev_err(&riic->adapter.dev,
"unsupported bus speed (%dHz). 400000 max\n",
t->bus_freq_hz);
clk_disable_unprepare(riic->clk);
return -EINVAL;
ret = -EINVAL;
goto out;
}
rate = clk_get_rate(riic->clk);
@ -332,8 +329,8 @@ static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
if (brl > (0x1F + 3)) {
dev_err(&riic->adapter.dev, "invalid speed (%lu). Too slow.\n",
(unsigned long)t->bus_freq_hz);
clk_disable_unprepare(riic->clk);
return -EINVAL;
ret = -EINVAL;
goto out;
}
brh = total_ticks - brl;
@ -378,9 +375,9 @@ static int riic_init_hw(struct riic_dev *riic, struct i2c_timings *t)
riic_clear_set_bit(riic, ICCR1_IICRST, 0, RIIC_ICCR1);
clk_disable_unprepare(riic->clk);
return 0;
out:
pm_runtime_put(riic->adapter.dev.parent);
return ret;
}
static struct riic_irq_desc riic_irqs[] = {
@ -439,28 +436,36 @@ static int riic_i2c_probe(struct platform_device *pdev)
i2c_parse_fw_timings(&pdev->dev, &i2c_t, true);
pm_runtime_enable(&pdev->dev);
ret = riic_init_hw(riic, &i2c_t);
if (ret)
return ret;
goto out;
ret = i2c_add_adapter(adap);
if (ret)
return ret;
goto out;
platform_set_drvdata(pdev, riic);
dev_info(&pdev->dev, "registered with %dHz bus speed\n",
i2c_t.bus_freq_hz);
return 0;
out:
pm_runtime_disable(&pdev->dev);
return ret;
}
static int riic_i2c_remove(struct platform_device *pdev)
{
struct riic_dev *riic = platform_get_drvdata(pdev);
pm_runtime_get_sync(&pdev->dev);
writeb(0, riic->base + RIIC_ICIER);
pm_runtime_put(&pdev->dev);
i2c_del_adapter(&riic->adapter);
pm_runtime_disable(&pdev->dev);
return 0;
}