From f5591da992b952624cf191ed4988360f921e9e57 Mon Sep 17 00:00:00 2001 From: Dragos Bogdan Date: Wed, 22 Jun 2016 08:30:42 -0300 Subject: [PATCH] [media] adv7604: Add support for hardware reset The part can be reset by a low pulse on the RESET pin (i.e. a hardware reset) with a minimum width of 5 ms. It is recommended to wait 5 ms after the low pulse before an I2C write is performed to the part. For safety reasons, the delays will be between 5 and 10 ms. The RESET pin can be tied high, so the GPIO is optional. Signed-off-by: Dragos Bogdan Reviewed-by: Lars-Peter Clausen Acked-by: Laurent Pinchart Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/adv7604.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/media/i2c/adv7604.c b/drivers/media/i2c/adv7604.c index 3ffb3231be3f..0b362eeb55c7 100644 --- a/drivers/media/i2c/adv7604.c +++ b/drivers/media/i2c/adv7604.c @@ -164,6 +164,7 @@ struct adv76xx_state { struct adv76xx_platform_data pdata; struct gpio_desc *hpd_gpio[4]; + struct gpio_desc *reset_gpio; struct v4l2_subdev sd; struct media_pad pads[ADV76XX_PAD_MAX]; @@ -3018,6 +3019,19 @@ static int configure_regmaps(struct adv76xx_state *state) return 0; } +static void adv76xx_reset(struct adv76xx_state *state) +{ + if (state->reset_gpio) { + /* ADV76XX can be reset by a low reset pulse of minimum 5 ms. */ + gpiod_set_value_cansleep(state->reset_gpio, 0); + usleep_range(5000, 10000); + gpiod_set_value_cansleep(state->reset_gpio, 1); + /* It is recommended to wait 5 ms after the low pulse before */ + /* an I2C write is performed to the ADV76XX. */ + usleep_range(5000, 10000); + } +} + static int adv76xx_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -3081,6 +3095,12 @@ static int adv76xx_probe(struct i2c_client *client, if (state->hpd_gpio[i]) v4l_info(client, "Handling HPD %u GPIO\n", i); } + state->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset", + GPIOD_OUT_HIGH); + if (IS_ERR(state->reset_gpio)) + return PTR_ERR(state->reset_gpio); + + adv76xx_reset(state); state->timings = cea640x480; state->format = adv76xx_format_info(state, MEDIA_BUS_FMT_YUYV8_2X8);