From: Andy Walls Date: Sun, 22 Jun 2008 04:27:00 +0000 (-0300) Subject: V4L/DVB (8068): cx18: Add I2C slave reset via GPIO upon initialization X-Git-Tag: v2.6.26-rc9~91^2~10 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1f09e8a25c9aaa4066b4593c1bf99a4cbcc38120;p=linux-2.6 V4L/DVB (8068): cx18: Add I2C slave reset via GPIO upon initialization cx18: Add I2C slave reset via GPIO upon initialization. One user, Michael , has reported this allows his HVR-1600 EEPROM to be consistently recognized when using (long,) 100 msec delays. The delays in this commit are nominal (10 & 40 msec) and need testing/tuning on boards with I2C problems to find the right values. Signed-off-by: Andy Walls Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/video/cx18/cx18-cards.c b/drivers/media/video/cx18/cx18-cards.c index c18865b0d6..bbf23fa459 100644 --- a/drivers/media/video/cx18/cx18-cards.c +++ b/drivers/media/video/cx18/cx18-cards.c @@ -82,6 +82,11 @@ static const struct cx18_card cx18_card_hvr1600_esmt = { }, .gpio_init.initial_value = 0x3001, .gpio_init.direction = 0x3001, + .gpio_i2c_slave_reset = { + .active_lo_mask = 0x3001, + .msecs_asserted = 10, + .msecs_recovery = 40, + }, .i2c = &cx18_i2c_std, }; @@ -122,6 +127,11 @@ static const struct cx18_card cx18_card_hvr1600_samsung = { }, .gpio_init.initial_value = 0x3001, .gpio_init.direction = 0x3001, + .gpio_i2c_slave_reset = { + .active_lo_mask = 0x3001, + .msecs_asserted = 10, + .msecs_recovery = 40, + }, .i2c = &cx18_i2c_std, }; diff --git a/drivers/media/video/cx18/cx18-cards.h b/drivers/media/video/cx18/cx18-cards.h index 3c2c0b9295..dc2dd945d4 100644 --- a/drivers/media/video/cx18/cx18-cards.h +++ b/drivers/media/video/cx18/cx18-cards.h @@ -78,6 +78,13 @@ struct cx18_gpio_init { /* set initial GPIO DIR and OUT values */ u32 initial_value; }; +struct cx18_gpio_i2c_slave_reset { + u32 active_lo_mask; /* GPIO outputs that reset i2c chips when low */ + u32 active_hi_mask; /* GPIO outputs that reset i2c chips when high */ + int msecs_asserted; /* time period reset must remain asserted */ + int msecs_recovery; /* time after deassert for chips to be ready */ +}; + struct cx18_card_tuner { v4l2_std_id std; /* standard for which the tuner is suitable */ int tuner; /* tuner ID (from tuner.h) */ @@ -114,7 +121,8 @@ struct cx18_card { /* GPIO card-specific settings */ u8 xceive_pin; /* XCeive tuner GPIO reset pin */ - struct cx18_gpio_init gpio_init; + struct cx18_gpio_init gpio_init; + struct cx18_gpio_i2c_slave_reset gpio_i2c_slave_reset; struct cx18_card_tuner tuners[CX18_CARD_MAX_TUNERS]; struct cx18_card_tuner_i2c *i2c; diff --git a/drivers/media/video/cx18/cx18-gpio.c b/drivers/media/video/cx18/cx18-gpio.c index ceb63653c9..b302833f6f 100644 --- a/drivers/media/video/cx18/cx18-gpio.c +++ b/drivers/media/video/cx18/cx18-gpio.c @@ -53,10 +53,34 @@ static void gpio_write(struct cx18 *cx) write_reg(((dir & 0xffff) << 16) | (val & 0xffff), CX18_REG_GPIO_OUT1); write_reg(dir & 0xffff0000, CX18_REG_GPIO_DIR2); - write_reg((dir & 0xffff0000) | ((val & 0xffff0000) >> 16), + write_reg_sync((dir & 0xffff0000) | ((val & 0xffff0000) >> 16), CX18_REG_GPIO_OUT2); } +void cx18_reset_i2c_slaves_gpio(struct cx18 *cx) +{ + const struct cx18_gpio_i2c_slave_reset *p; + + p = &cx->card->gpio_i2c_slave_reset; + + if ((p->active_lo_mask | p->active_hi_mask) == 0) + return; + + /* Assuming that the masks are a subset of the bits in gpio_dir */ + + /* Assert */ + cx->gpio_val = + (cx->gpio_val | p->active_hi_mask) & ~(p->active_lo_mask); + gpio_write(cx); + schedule_timeout_uninterruptible(msecs_to_jiffies(p->msecs_asserted)); + + /* Deassert */ + cx->gpio_val = + (cx->gpio_val | p->active_lo_mask) & ~(p->active_hi_mask); + gpio_write(cx); + schedule_timeout_uninterruptible(msecs_to_jiffies(p->msecs_recovery)); +} + void cx18_gpio_init(struct cx18 *cx) { cx->gpio_dir = cx->card->gpio_init.direction; diff --git a/drivers/media/video/cx18/cx18-gpio.h b/drivers/media/video/cx18/cx18-gpio.h index 41bac8856b..525c328f74 100644 --- a/drivers/media/video/cx18/cx18-gpio.h +++ b/drivers/media/video/cx18/cx18-gpio.h @@ -21,4 +21,5 @@ */ void cx18_gpio_init(struct cx18 *cx); +void cx18_reset_i2c_slaves_gpio(struct cx18 *cx); int cx18_reset_tuner_gpio(void *dev, int cmd, int value); diff --git a/drivers/media/video/cx18/cx18-i2c.c b/drivers/media/video/cx18/cx18-i2c.c index 1d6c51a753..680bc4e35b 100644 --- a/drivers/media/video/cx18/cx18-i2c.c +++ b/drivers/media/video/cx18/cx18-i2c.c @@ -405,6 +405,8 @@ int init_cx18_i2c(struct cx18 *cx) cx18_setscl(&cx->i2c_algo_cb_data[1], 1); cx18_setsda(&cx->i2c_algo_cb_data[1], 1); + cx18_reset_i2c_slaves_gpio(cx); + return i2c_bit_add_bus(&cx->i2c_adap[0]) || i2c_bit_add_bus(&cx->i2c_adap[1]); }