diff options
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-sh_mobile.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index 007818b3e174..7193bcfdd940 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -150,6 +150,7 @@ struct sh_mobile_i2c_data { struct sh_mobile_dt_config { int clks_per_count; + void (*setup)(struct sh_mobile_i2c_data *pd); }; #define IIC_FLAG_HAS_ICIC67 (1 << 0) @@ -164,6 +165,7 @@ struct sh_mobile_dt_config { #define ICIC 0x0c #define ICCL 0x10 #define ICCH 0x14 +#define ICSTART 0x70 /* Register bits */ #define ICCR_ICE 0x80 @@ -190,6 +192,8 @@ struct sh_mobile_dt_config { #define ICIC_WAITE 0x02 #define ICIC_DTEE 0x01 +#define ICSTART_ICSTART 0x10 + static void iic_wr(struct sh_mobile_i2c_data *pd, int offs, unsigned char data) { if (offs == ICIC) @@ -782,6 +786,33 @@ static struct i2c_algorithm sh_mobile_i2c_algorithm = { .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 = { .clks_per_count = 1, }; @@ -790,9 +821,15 @@ static const struct sh_mobile_dt_config fast_clock_dt_config = { .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[] = { { .compatible = "renesas,rmobile-iic", .data = &default_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-r8a7791", .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; pd->clks_per_count = config->clks_per_count; + + if (config->setup) + config->setup(pd); } } else { if (pdata && pdata->bus_speed) |