tpm2: tis_spi: add the possibility to reset the chip with a gpio
On some designs, the reset line could not be connected to the SoC reset
line, in this case, request the GPIO and ensure the chip gets reset.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/tpm/tpm2_tis_spi.c b/drivers/tpm/tpm2_tis_spi.c
index 518a08b..c5d17a6 100644
--- a/drivers/tpm/tpm2_tis_spi.c
+++ b/drivers/tpm/tpm2_tis_spi.c
@@ -23,6 +23,7 @@
#include <linux/compiler.h>
#include <linux/types.h>
#include <linux/unaligned/be_byteshift.h>
+#include <asm-generic/gpio.h>
#include "tpm_tis.h"
#include "tpm_internal.h"
@@ -574,6 +575,21 @@
struct tpm_chip *chip = dev_get_priv(dev);
int ret;
+ if (IS_ENABLED(CONFIG_DM_GPIO)) {
+ struct gpio_desc reset_gpio;
+
+ ret = gpio_request_by_name(dev, "gpio-reset", 0,
+ &reset_gpio, GPIOD_IS_OUT);
+ if (ret) {
+ log(LOGC_NONE, LOGL_NOTICE, "%s: missing reset GPIO\n",
+ __func__);
+ } else {
+ dm_gpio_set_value(&reset_gpio, 0);
+ mdelay(1);
+ dm_gpio_set_value(&reset_gpio, 1);
+ }
+ }
+
/* Ensure a minimum amount of time elapsed since reset of the TPM */
mdelay(drv_data->time_before_first_cmd_ms);