V4L/DVB (8068): cx18: Add I2C slave reset via GPIO upon initialization

cx18: Add I2C slave reset via GPIO upon initialization.  One user,
Michael <msd4824@yahoo.com>, 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 <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

diff --git a/drivers/media/video/cx18/cx18-cards.c b/drivers/media/video/cx18/cx18-cards.c
index c18865b..bbf23fa 100644 (file)
--- 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 3c2c0b9..dc2dd94 100644 (file)
--- 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 ceb6365..b302833 100644 (file)
--- 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 41bac88..525c328 100644 (file)
--- 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 1d6c51a..680bc4e 100644 (file)
--- 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]);
 }