i2c: nomadik: adopt pinctrl support
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>
diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index 8b2ffcf..dd6a691 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -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 @@
* @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 @@
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 @@
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 @@
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 @@
{
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 @@
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 @@
err_no_ioremap:
amba_set_drvdata(adev, NULL);
kfree(dev);
+ err_pinctrl:
err_no_mem:
return ret;