diff options
author | Heiko Stübner <heiko@sntech.de> | 2014-07-20 01:50:11 +0200 |
---|---|---|
committer | Linus Walleij <linus.walleij@linaro.org> | 2014-07-23 16:41:16 +0200 |
commit | b547c8007e83a476b946237d09227668fe286a57 (patch) | |
tree | 88aff7bafb5c9fc363ead99c79d8c72bbf0b859e /drivers/pinctrl/pinctrl-rockchip.c | |
parent | 66d750e1d03875512dec38993b4cac3640a85e54 (diff) | |
download | linux-b547c8007e83a476b946237d09227668fe286a57.tar.bz2 |
pinctrl: rockchip: add drive-strength control for rk3288
The rk3288 is the first Rockchip soc handling the drive strength on a per-pin
basis, while the older ones can set the drive-strength only for specific
pin-groups. Therefore limit setting the drive-strength to this soc for now.
Signed-off-by: Heiko Stübner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/pinctrl/pinctrl-rockchip.c')
-rw-r--r-- | drivers/pinctrl/pinctrl-rockchip.c | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinctrl-rockchip.c b/drivers/pinctrl/pinctrl-rockchip.c index 3e239c75f52c..5e8b2e04cd7a 100644 --- a/drivers/pinctrl/pinctrl-rockchip.c +++ b/drivers/pinctrl/pinctrl-rockchip.c @@ -573,6 +573,98 @@ static void rk3288_calc_pull_reg_and_bit(struct rockchip_pin_bank *bank, } } +#define RK3288_DRV_PMU_OFFSET 0x70 +#define RK3288_DRV_GRF_OFFSET 0x1c0 +#define RK3288_DRV_BITS_PER_PIN 2 +#define RK3288_DRV_PINS_PER_REG 8 +#define RK3288_DRV_BANK_STRIDE 16 +static int rk3288_drv_list[] = { 2, 4, 8, 12 }; + +static void rk3288_calc_drv_reg_and_bit(struct rockchip_pin_bank *bank, + int pin_num, struct regmap **regmap, + int *reg, u8 *bit) +{ + struct rockchip_pinctrl *info = bank->drvdata; + + /* The first 24 pins of the first bank are located in PMU */ + if (bank->bank_num == 0) { + *regmap = info->regmap_pmu; + *reg = RK3288_DRV_PMU_OFFSET; + + *reg += ((pin_num / RK3288_DRV_PINS_PER_REG) * 4); + *bit = pin_num % RK3288_DRV_PINS_PER_REG; + *bit *= RK3288_DRV_BITS_PER_PIN; + } else { + *regmap = info->regmap_base; + *reg = RK3288_DRV_GRF_OFFSET; + + /* correct the offset, as we're starting with the 2nd bank */ + *reg -= 0x10; + *reg += bank->bank_num * RK3288_DRV_BANK_STRIDE; + *reg += ((pin_num / RK3288_DRV_PINS_PER_REG) * 4); + + *bit = (pin_num % RK3288_DRV_PINS_PER_REG); + *bit *= RK3288_DRV_BITS_PER_PIN; + } +} + +static int rk3288_get_drive(struct rockchip_pin_bank *bank, int pin_num) +{ + struct regmap *regmap; + int reg, ret; + u32 data; + u8 bit; + + rk3288_calc_drv_reg_and_bit(bank, pin_num, ®map, ®, &bit); + + ret = regmap_read(regmap, reg, &data); + if (ret) + return ret; + + data >>= bit; + data &= (1 << RK3288_DRV_BITS_PER_PIN) - 1; + + return rk3288_drv_list[data]; +} + +static int rk3288_set_drive(struct rockchip_pin_bank *bank, int pin_num, + int strength) +{ + struct rockchip_pinctrl *info = bank->drvdata; + struct regmap *regmap; + unsigned long flags; + int reg, ret, i; + u32 data; + u8 bit; + + rk3288_calc_drv_reg_and_bit(bank, pin_num, ®map, ®, &bit); + + ret = -EINVAL; + for (i = 0; i < ARRAY_SIZE(rk3288_drv_list); i++) { + if (rk3288_drv_list[i] == strength) { + ret = i; + break; + } + } + + if (ret < 0) { + dev_err(info->dev, "unsupported driver strength %d\n", + strength); + return ret; + } + + spin_lock_irqsave(&bank->slock, flags); + + /* enable the write to the equivalent lower bits */ + data = ((1 << RK3288_DRV_BITS_PER_PIN) - 1) << (bit + 16); + data |= (ret << bit); + + ret = regmap_write(regmap, reg, data); + spin_unlock_irqrestore(&bank->slock, flags); + + return ret; +} + static int rockchip_get_pull(struct rockchip_pin_bank *bank, int pin_num) { struct rockchip_pinctrl *info = bank->drvdata; @@ -870,6 +962,15 @@ static int rockchip_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin, if (rc) return rc; break; + case PIN_CONFIG_DRIVE_STRENGTH: + /* rk3288 is the first with per-pin drive-strength */ + if (info->ctrl->type != RK3288) + return -ENOTSUPP; + + rc = rk3288_set_drive(bank, pin - bank->pin_base, arg); + if (rc < 0) + return rc; + break; default: return -ENOTSUPP; break; @@ -919,6 +1020,17 @@ static int rockchip_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin, arg = rc ? 1 : 0; break; + case PIN_CONFIG_DRIVE_STRENGTH: + /* rk3288 is the first with per-pin drive-strength */ + if (info->ctrl->type != RK3288) + return -ENOTSUPP; + + rc = rk3288_get_drive(bank, pin - bank->pin_base); + if (rc < 0) + return rc; + + arg = rc; + break; default: return -ENOTSUPP; break; |