diff options
Diffstat (limited to 'drivers/net/pse-pd/tps23881.c')
| -rw-r--r-- | drivers/net/pse-pd/tps23881.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/net/pse-pd/tps23881.c b/drivers/net/pse-pd/tps23881.c index 61f6ad9c1934..5c4e88be46ee 100644 --- a/drivers/net/pse-pd/tps23881.c +++ b/drivers/net/pse-pd/tps23881.c @@ -5,8 +5,10 @@ * Copyright (c) 2023 Bootlin, Kory Maincent <kory.maincent@bootlin.com> */ +#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> @@ -29,6 +31,8 @@ #define TPS23881_REG_TPON BIT(0) #define TPS23881_REG_FWREV 0x41 #define TPS23881_REG_DEVID 0x43 +#define TPS23881_REG_DEVID_MASK 0xF0 +#define TPS23881_DEVICE_ID 0x02 #define TPS23881_REG_SRAM_CTRL 0x60 #define TPS23881_REG_SRAM_DATA 0x61 @@ -734,6 +738,7 @@ 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; @@ -746,11 +751,30 @@ static int tps23881_i2c_probe(struct i2c_client *client) 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 (ret != 0x22) { + if (FIELD_GET(TPS23881_REG_DEVID_MASK, ret) != TPS23881_DEVICE_ID) { dev_err(dev, "Wrong device ID\n"); return -ENXIO; } |