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:
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@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Christophe Ricard <christophe-h.ricard@xxxxxx>
---
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 ?
@@ -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
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