The TPS23880/1 has an active-low reset pin that some boards connect to
the SoC to control when the TPS23880 is pulled out of reset.
Add support for this via a reset-gpios property in the DTS.
Signed-off-by: Kyle Swenson <kyle.swenson@xxxxxxxx>
---
drivers/net/pse-pd/tps23881.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/net/pse-pd/tps23881.c b/drivers/net/pse-pd/tps23881.c
index 2ea75686a319..5c4e88be46ee 100644
--- a/drivers/net/pse-pd/tps23881.c
+++ b/drivers/net/pse-pd/tps23881.c
@@ -6,10 +6,11 @@
*/
#include <linux/bitfield.h>
#include <linux/delay.h>
#include <linux/firmware.h>
+#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pse-pd/pse.h>
@@ -735,10 +736,11 @@ static int tps23881_flash_sram_fw(struct i2c_client *client)
static int tps23881_i2c_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct tps23881_priv *priv;
+ struct gpio_desc *reset;
int ret;
u8 val;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
dev_err(dev, "i2c check functionality failed\n");
@@ -747,10 +749,29 @@ static int tps23881_i2c_probe(struct i2c_client *client)
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
+ reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(reset))
+ return dev_err_probe(&client->dev, PTR_ERR(reset), "Failed to get reset GPIO\n");
+
+ if (reset) {
+ /* TPS23880 datasheet (Rev G) indicates minimum reset pulse is 5us */
+ usleep_range(5, 10);
+ gpiod_set_value_cansleep(reset, 0); /* De-assert reset */
+
+ /* TPS23880 datasheet indicates the minimum time after power on reset
+ * should be 20ms, but the document describing how to load SRAM ("How
+ * to Load TPS2388x SRAM and Parity Code over I2C" (Rev E))
+ * indicates we should delay that programming by at least 50ms. So
+ * we'll wait the entire 50ms here to ensure we're safe to go to the
+ * SRAM loading proceedure.
+ */
+ msleep(50);
+ }
+
ret = i2c_smbus_read_byte_data(client, TPS23881_REG_DEVID);
if (ret < 0)
return ret;
if (FIELD_GET(TPS23881_REG_DEVID_MASK, ret) != TPS23881_DEVICE_ID) {
--
2.43.0
