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i2c: sh_mobile: add errata workaround

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This used to be in platform init code. We want it to do in the driver
now. This is basically a code move and a new compatible added.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Wolfram Sang 2015-06-09 16:14:39 +09:00 committed by Wolfram Sang
parent f30dc5208c
commit 3ded3743a0
1 changed files with 40 additions and 0 deletions
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40
drivers/i2c/busses/i2c-sh_mobile.c
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@ -150,6 +150,7 @@ struct sh_mobile_i2c_data {
struct sh_mobile_dt_config { struct sh_mobile_dt_config {
int clks_per_count; int clks_per_count;
void (*setup)(struct sh_mobile_i2c_data *pd);
}; };
#define IIC_FLAG_HAS_ICIC67 (1 << 0) #define IIC_FLAG_HAS_ICIC67 (1 << 0)
@ -164,6 +165,7 @@ struct sh_mobile_dt_config {
#define ICIC 0x0c #define ICIC 0x0c
#define ICCL 0x10 #define ICCL 0x10
#define ICCH 0x14 #define ICCH 0x14
#define ICSTART 0x70
/* Register bits */ /* Register bits */
#define ICCR_ICE 0x80 #define ICCR_ICE 0x80
@ -190,6 +192,8 @@ struct sh_mobile_dt_config {
#define ICIC_WAITE 0x02 #define ICIC_WAITE 0x02
#define ICIC_DTEE 0x01 #define ICIC_DTEE 0x01
#define ICSTART_ICSTART 0x10
static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data) static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data)
{ {
if (offs == ICIC) if (offs == ICIC)
@ -782,6 +786,33 @@ static struct i2c_algorithm sh_mobile_i2c_algorithm = {
.master_xfer = sh_mobile_i2c_xfer, .master_xfer = sh_mobile_i2c_xfer,
}; };
/*
* r8a7740 chip has lasting errata on I2C I/O pad reset.
* this is work-around for it.
*/
static void sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
{
iic_set_clr(pd, ICCR, ICCR_ICE, 0);
iic_rd(pd, ICCR); /* dummy read */
iic_set_clr(pd, ICSTART, ICSTART_ICSTART, 0);
iic_rd(pd, ICSTART); /* dummy read */
udelay(10);
iic_wr(pd, ICCR, ICCR_SCP);
iic_wr(pd, ICSTART, 0);
udelay(10);
iic_wr(pd, ICCR, ICCR_TRS);
udelay(10);
iic_wr(pd, ICCR, 0);
udelay(10);
iic_wr(pd, ICCR, ICCR_TRS);
udelay(10);
}
static const struct sh_mobile_dt_config default_dt_config = { static const struct sh_mobile_dt_config default_dt_config = {
.clks_per_count = 1, .clks_per_count = 1,
}; };
@ -790,9 +821,15 @@ static const struct sh_mobile_dt_config fast_clock_dt_config = {
.clks_per_count = 2, .clks_per_count = 2,
}; };
static const struct sh_mobile_dt_config r8a7740_dt_config = {
.clks_per_count = 1,
.setup = sh_mobile_i2c_r8a7740_workaround,
};
static const struct of_device_id sh_mobile_i2c_dt_ids[] = { static const struct of_device_id sh_mobile_i2c_dt_ids[] = {
{ .compatible = "renesas,rmobile-iic", .data = &default_dt_config }, { .compatible = "renesas,rmobile-iic", .data = &default_dt_config },
{ .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a73a4", .data = &fast_clock_dt_config },
{ .compatible = "renesas,iic-r8a7740", .data = &r8a7740_dt_config },
{ .compatible = "renesas,iic-r8a7790", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7790", .data = &fast_clock_dt_config },
{ .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7791", .data = &fast_clock_dt_config },
{ .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config }, { .compatible = "renesas,iic-r8a7792", .data = &fast_clock_dt_config },
@ -885,6 +922,9 @@ static int sh_mobile_i2c_probe(struct platform_device *dev)
config = match->data; config = match->data;
pd->clks_per_count = config->clks_per_count; pd->clks_per_count = config->clks_per_count;
if (config->setup)
config->setup(pd);
} }
} else { } else {
if (pdata && pdata->bus_speed) if (pdata && pdata->bus_speed)