Commit 3ded3743 authored by Wolfram Sang's avatar Wolfram Sang Committed by Wolfram Sang

i2c: sh_mobile: add errata workaround

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: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: default avatarKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: default avatarSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent f30dc520
......@@ -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)
......
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