From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Wolfram Sang <wsa@the-dreams.de>,
Chris Brandt <chris.brandt@renesas.com>
Cc: linux-i2c@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] i2c: riic: Add Runtime PM support
Date: Wed, 20 Mar 2019 11:30:03 +0100 [thread overview]
Message-ID: <20190320103003.20107-1-geert+renesas@glider.be> (raw)
- 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>
---
I don't think it's worth splitting off the last bug fix in a separate
(first) patch, using explicit clock handling, as that will be replaced
immediately by Runtime PM calls.
---
drivers/i2c/busses/i2c-riic.c | 43 +++++++++++++++++++----------------
1 file changed, 24 insertions(+), 19 deletions(-)
diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index b75ff144b5704293..f31413fd9521ef9f 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c
@@ -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;
}
--
2.17.1
next reply other threads:[~2019-03-20 10:30 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-20 10:30 Geert Uytterhoeven [this message]
2019-03-20 16:20 ` [PATCH] i2c: riic: Add Runtime PM support Niklas Söderlund
2019-04-15 12:17 ` Wolfram Sang
2019-04-15 12:43 ` Chris Brandt
2019-04-15 12:46 ` Wolfram Sang
2019-04-15 18:56 ` Chris Brandt
2019-04-23 21:29 ` Wolfram Sang
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