Re: [PATCH v4 1/4] tpm/tpm_i2c_stm_st33: Replace access to io_lpcpd from struct st33zp24_platform_data to tpm_stm_dev

Hi Peter,

The lpcpd pin allow the tpm to go in low power mode keeping the current 
context in RAM.
As mention in the dts documentation:
"If set, power must be present when the platform is going into 
sleep/hibernate mode."
The gpio state is enough to save and restore the context.
This allows for example saving some memory wear or quicker state changes...

Best Regards
Christophe
On 26/01/2015 23:15, Peter Hüwe wrote:

Hi Christophe,
Am Sonntag, 25. Januar 2015, 22:11:30 schrieb Christophe Ricard:

quoted

io_lpcpd is accessible from struct tpm_stm_dev.
struct st33zp24_platform_data is only valid when using static platform
configuration data, not when using dts.

Reviewed-by: Jason Gunthorpe <jason.gunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
Signed-off-by: Christophe Ricard <redacted>
---
  drivers/char/tpm/tpm_i2c_stm_st33.c | 18 +++++++++++-------
  1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/char/tpm/tpm_i2c_stm_st33.c

b/drivers/char/tpm/tpm_i2c_stm_st33.c index 612845b..882c60a 100644

--- a/drivers/char/tpm/tpm_i2c_stm_st33.c
+++ b/drivers/char/tpm/tpm_i2c_stm_st33.c

@@ -837,11 +837,14 @@ static int tpm_stm_i2c_remove(struct i2c_client

*client) */
  static int tpm_stm_i2c_pm_suspend(struct device *dev)
  {
-	struct st33zp24_platform_data *pin_infos = dev->platform_data;
+	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_stm_dev *tpm_dev;
  	int ret = 0;

-	if (gpio_is_valid(pin_infos->io_lpcpd))
-		gpio_set_value(pin_infos->io_lpcpd, 0);
+	tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
+
+	if (gpio_is_valid(tpm_dev->io_lpcpd))
+		gpio_set_value(tpm_dev->io_lpcpd, 0);
  	else
  		ret = tpm_pm_suspend(dev);

I know this is not changed by this patch, but
don't you need to send a tpm savestate? or is this implicit by pulling
io_lpcpd ?

quoted

@@ -856,12 +859,13 @@ static int tpm_stm_i2c_pm_suspend(struct device *dev)
  static int tpm_stm_i2c_pm_resume(struct device *dev)
  {
  	struct tpm_chip *chip = dev_get_drvdata(dev);
-	struct st33zp24_platform_data *pin_infos = dev->platform_data;
-
+	struct tpm_stm_dev *tpm_dev;
  	int ret = 0;

-	if (gpio_is_valid(pin_infos->io_lpcpd)) {
-		gpio_set_value(pin_infos->io_lpcpd, 1);
+	tpm_dev = (struct tpm_stm_dev *)TPM_VPRIV(chip);
+
+	if (gpio_is_valid(tpm_dev->io_lpcpd)) {
+		gpio_set_value(tpm_dev->io_lpcpd, 1);
  		ret = wait_for_stat(chip,
  				TPM_STS_VALID, chip->vendor.timeout_b,
  				&chip->vendor.read_queue, false);

Same applies to startup(STATE) on resume?

Peter

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html