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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>
This commit is contained in:
Andy Walls 2008-06-22 01:27:00 -03:00 committed by Mauro Carvalho Chehab
parent 08cf7b2ed1
commit 1f09e8a25c
5 changed files with 47 additions and 2 deletions

View File

@ -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,
};

View File

@ -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;

View File

@ -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;

View File

@ -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);

View File

@ -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]);
}