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i2c: nomadik: adopt pinctrl support

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Amend the I2C nomadik pin controller to optionally take a pin control
handle and set the state of the pins to:

- "default" on boot, resume and before performing an i2c transfer
- "idle" after initial default, after resume default, and after each
   i2c xfer
- "sleep" on suspend()

This should make it possible to optimize energy usage for the pins
both for the suspend/resume cycle, and for runtime cases inbetween
I2C transfers.

Signed-off-by: Patrice Chotard <patrice.chotard@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[wsa: fixed braces on one else-branch]
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
This commit is contained in:
Patrice Chotard 2013-01-24 09:47:22 +01:00 committed by Wolfram Sang
parent 631056c399
commit 24e9e157d5
1 changed files with 89 additions and 0 deletions
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89
drivers/i2c/busses/i2c-nomadik.c
View File

@ -26,6 +26,7 @@
#include <linux/platform_data/i2c-nomadik.h>
#include <linux/of.h>
#include <linux/of_i2c.h>
#include <linux/pinctrl/consumer.h>
#define DRIVER_NAME "nmk-i2c"
@ -147,6 +148,10 @@ struct i2c_nmk_client {
* @stop: stop condition.
* @xfer_complete: acknowledge completion for a I2C message.
* @result: controller propogated result.
* @pinctrl: pinctrl handle.
* @pins_default: default state for the pins.
* @pins_idle: idle state for the pins.
* @pins_sleep: sleep state for the pins.
* @busy: Busy doing transfer.
*/
struct nmk_i2c_dev {
@ -160,6 +165,11 @@ struct nmk_i2c_dev {
int stop;
struct completion xfer_complete;
int result;
/* Three pin states - default, idle & sleep */
struct pinctrl *pinctrl;
struct pinctrl_state *pins_default;
struct pinctrl_state *pins_idle;
struct pinctrl_state *pins_sleep;
bool busy;
};
@ -636,6 +646,15 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
goto out_clk;
}
/* Optionaly enable pins to be muxed in and configured */
if (!IS_ERR(dev->pins_default)) {
status = pinctrl_select_state(dev->pinctrl,
dev->pins_default);
if (status)
dev_err(&dev->adev->dev,
"could not set default pins\n");
}
status = init_hw(dev);
if (status)
goto out;
@ -663,6 +682,15 @@ static int nmk_i2c_xfer(struct i2c_adapter *i2c_adap,
out:
clk_disable_unprepare(dev->clk);
out_clk:
/* Optionally let pins go into idle state */
if (!IS_ERR(dev->pins_idle)) {
status = pinctrl_select_state(dev->pinctrl,
dev->pins_idle);
if (status)
dev_err(&dev->adev->dev,
"could not set pins to idle state\n");
}
pm_runtime_put_sync(&dev->adev->dev);
dev->busy = false;
@ -857,15 +885,41 @@ static int nmk_i2c_suspend(struct device *dev)
{
struct amba_device *adev = to_amba_device(dev);
struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);
int ret;
if (nmk_i2c->busy)
return -EBUSY;
if (!IS_ERR(nmk_i2c->pins_sleep)) {
ret = pinctrl_select_state(nmk_i2c->pinctrl,
nmk_i2c->pins_sleep);
if (ret)
dev_err(dev, "could not set pins to sleep state\n");
}
return 0;
}
static int nmk_i2c_resume(struct device *dev)
{
struct amba_device *adev = to_amba_device(dev);
struct nmk_i2c_dev *nmk_i2c = amba_get_drvdata(adev);
int ret;
/* First go to the default state */
if (!IS_ERR(nmk_i2c->pins_default)) {
ret = pinctrl_select_state(nmk_i2c->pinctrl,
nmk_i2c->pins_default);
if (ret)
dev_err(dev, "could not set pins to default state\n");
}
/* Then let's idle the pins until the next transfer happens */
if (!IS_ERR(nmk_i2c->pins_idle)) {
ret = pinctrl_select_state(nmk_i2c->pinctrl,
nmk_i2c->pins_idle);
if (ret)
dev_err(dev, "could not set pins to idle state\n");
}
return 0;
}
#else
@ -953,6 +1007,40 @@ static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
dev->adev = adev;
amba_set_drvdata(adev, dev);
dev->pinctrl = devm_pinctrl_get(&adev->dev);
if (IS_ERR(dev->pinctrl)) {
ret = PTR_ERR(dev->pinctrl);
goto err_pinctrl;
}
dev->pins_default = pinctrl_lookup_state(dev->pinctrl,
PINCTRL_STATE_DEFAULT);
if (IS_ERR(dev->pins_default)) {
dev_err(&adev->dev, "could not get default pinstate\n");
} else {
ret = pinctrl_select_state(dev->pinctrl,
dev->pins_default);
if (ret)
dev_dbg(&adev->dev, "could not set default pinstate\n");
}
dev->pins_idle = pinctrl_lookup_state(dev->pinctrl,
PINCTRL_STATE_IDLE);
if (IS_ERR(dev->pins_idle)) {
dev_dbg(&adev->dev, "could not get idle pinstate\n");
} else {
/* If possible, let's go to idle until the first transfer */
ret = pinctrl_select_state(dev->pinctrl,
dev->pins_idle);
if (ret)
dev_dbg(&adev->dev, "could not set idle pinstate\n");
}
dev->pins_sleep = pinctrl_lookup_state(dev->pinctrl,
PINCTRL_STATE_SLEEP);
if (IS_ERR(dev->pins_sleep))
dev_dbg(&adev->dev, "could not get sleep pinstate\n");
dev->virtbase = ioremap(adev->res.start, resource_size(&adev->res));
if (!dev->virtbase) {
ret = -ENOMEM;
@ -1022,6 +1110,7 @@ static int nmk_i2c_probe(struct amba_device *adev, const struct amba_id *id)
err_no_ioremap:
amba_set_drvdata(adev, NULL);
kfree(dev);
err_pinctrl:
err_no_mem:
return ret;