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pinctrl: mediatek: support rsel feature
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This patch supports rsel(resistance selection) feature for I2C pins.
It provides more resistance selection solution in different ICs.
It provides rsel define and si unit solution by identifying
"mediatek,rsel_resistance_in_si_unit" property in pio dtsi node.

Signed-off-by: Zhiyong Tao <zhiyong.tao@mediatek.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20210924080632.28410-5-zhiyong.tao@mediatek.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Zhiyong Tao authored and Linus Walleij committed Oct 2, 2021
1 parent 25a74c0 commit fb34a9a
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Showing 3 changed files with 289 additions and 48 deletions.
231 changes: 201 additions & 30 deletions drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -661,6 +661,181 @@ static int mtk_pinconf_bias_set_pupd_r1_r0(struct mtk_pinctrl *hw,
return err;
}

static int mtk_hw_pin_rsel_lookup(struct mtk_pinctrl *hw,
const struct mtk_pin_desc *desc,
u32 pullup, u32 arg, u32 *rsel_val)
{
const struct mtk_pin_rsel *rsel;
int check;
bool found = false;

rsel = hw->soc->pin_rsel;

for (check = 0; check <= hw->soc->npin_rsel - 1; check++) {
if (desc->number >= rsel[check].s_pin &&
desc->number <= rsel[check].e_pin) {
if (pullup) {
if (rsel[check].up_rsel == arg) {
found = true;
*rsel_val = rsel[check].rsel_index;
break;
}
} else {
if (rsel[check].down_rsel == arg) {
found = true;
*rsel_val = rsel[check].rsel_index;
break;
}
}
}
}

if (!found) {
dev_err(hw->dev, "Not support rsel value %d Ohm for pin = %d (%s)\n",
arg, desc->number, desc->name);
return -ENOTSUPP;
}

return 0;
}

static int mtk_pinconf_bias_set_rsel(struct mtk_pinctrl *hw,
const struct mtk_pin_desc *desc,
u32 pullup, u32 arg)
{
int err, rsel_val;

if (hw->rsel_si_unit) {
/* find pin rsel_index from pin_rsel array*/
err = mtk_hw_pin_rsel_lookup(hw, desc, pullup, arg, &rsel_val);
if (err)
goto out;
} else {
if (arg < MTK_PULL_SET_RSEL_000 ||
arg > MTK_PULL_SET_RSEL_111) {
err = -EINVAL;
goto out;
}

rsel_val = arg - MTK_PULL_SET_RSEL_000;
}

err = mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_RSEL, rsel_val);
if (err)
goto out;

err = mtk_pinconf_bias_set_pu_pd(hw, desc, pullup, MTK_ENABLE);

out:
return err;
}

int mtk_pinconf_bias_set_combo(struct mtk_pinctrl *hw,
const struct mtk_pin_desc *desc,
u32 pullup, u32 arg)
{
int err = -ENOTSUPP;
u32 try_all_type;

if (hw->soc->pull_type)
try_all_type = hw->soc->pull_type[desc->number];
else
try_all_type = MTK_PULL_TYPE_MASK;

if (try_all_type & MTK_PULL_RSEL_TYPE) {
err = mtk_pinconf_bias_set_rsel(hw, desc, pullup, arg);
if (!err)
return err;
}

if (try_all_type & MTK_PULL_PU_PD_TYPE) {
err = mtk_pinconf_bias_set_pu_pd(hw, desc, pullup, arg);
if (!err)
return err;
}

if (try_all_type & MTK_PULL_PULLSEL_TYPE) {
err = mtk_pinconf_bias_set_pullsel_pullen(hw, desc,
pullup, arg);
if (!err)
return err;
}

if (try_all_type & MTK_PULL_PUPD_R1R0_TYPE)
err = mtk_pinconf_bias_set_pupd_r1_r0(hw, desc, pullup, arg);

if (err)
dev_err(hw->dev, "Invalid pull argument\n");

return err;
}
EXPORT_SYMBOL_GPL(mtk_pinconf_bias_set_combo);

static int mtk_rsel_get_si_unit(struct mtk_pinctrl *hw,
const struct mtk_pin_desc *desc,
u32 pullup, u32 rsel_val, u32 *si_unit)
{
const struct mtk_pin_rsel *rsel;
int check;

rsel = hw->soc->pin_rsel;

for (check = 0; check <= hw->soc->npin_rsel - 1; check++) {
if (desc->number >= rsel[check].s_pin &&
desc->number <= rsel[check].e_pin) {
if (rsel_val == rsel[check].rsel_index) {
if (pullup)
*si_unit = rsel[check].up_rsel;
else
*si_unit = rsel[check].down_rsel;
break;
}
}
}

return 0;
}

static int mtk_pinconf_bias_get_rsel(struct mtk_pinctrl *hw,
const struct mtk_pin_desc *desc,
u32 *pullup, u32 *enable)
{
int pu, pd, rsel, err;

err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_RSEL, &rsel);
if (err)
goto out;

err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PU, &pu);
if (err)
goto out;

err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_PD, &pd);

if (pu == 0 && pd == 0) {
*pullup = 0;
*enable = MTK_DISABLE;
} else if (pu == 1 && pd == 0) {
*pullup = 1;
if (hw->rsel_si_unit)
mtk_rsel_get_si_unit(hw, desc, *pullup, rsel, enable);
else
*enable = rsel + MTK_PULL_SET_RSEL_000;
} else if (pu == 0 && pd == 1) {
*pullup = 0;
if (hw->rsel_si_unit)
mtk_rsel_get_si_unit(hw, desc, *pullup, rsel, enable);
else
*enable = rsel + MTK_PULL_SET_RSEL_000;
} else {
err = -EINVAL;
goto out;
}

out:
return err;
}

static int mtk_pinconf_bias_get_pu_pd(struct mtk_pinctrl *hw,
const struct mtk_pin_desc *desc,
u32 *pullup, u32 *enable)
Expand Down Expand Up @@ -742,44 +917,40 @@ static int mtk_pinconf_bias_get_pupd_r1_r0(struct mtk_pinctrl *hw,
return err;
}

int mtk_pinconf_bias_set_combo(struct mtk_pinctrl *hw,
const struct mtk_pin_desc *desc,
u32 pullup, u32 arg)
{
int err;

err = mtk_pinconf_bias_set_pu_pd(hw, desc, pullup, arg);
if (!err)
goto out;

err = mtk_pinconf_bias_set_pullsel_pullen(hw, desc, pullup, arg);
if (!err)
goto out;

err = mtk_pinconf_bias_set_pupd_r1_r0(hw, desc, pullup, arg);

out:
return err;
}
EXPORT_SYMBOL_GPL(mtk_pinconf_bias_set_combo);

int mtk_pinconf_bias_get_combo(struct mtk_pinctrl *hw,
const struct mtk_pin_desc *desc,
u32 *pullup, u32 *enable)
{
int err;
int err = -ENOTSUPP;
u32 try_all_type;

err = mtk_pinconf_bias_get_pu_pd(hw, desc, pullup, enable);
if (!err)
goto out;
if (hw->soc->pull_type)
try_all_type = hw->soc->pull_type[desc->number];
else
try_all_type = MTK_PULL_TYPE_MASK;

err = mtk_pinconf_bias_get_pullsel_pullen(hw, desc, pullup, enable);
if (!err)
goto out;
if (try_all_type & MTK_PULL_RSEL_TYPE) {
err = mtk_pinconf_bias_get_rsel(hw, desc, pullup, enable);
if (!err)
return err;
}

err = mtk_pinconf_bias_get_pupd_r1_r0(hw, desc, pullup, enable);
if (try_all_type & MTK_PULL_PU_PD_TYPE) {
err = mtk_pinconf_bias_get_pu_pd(hw, desc, pullup, enable);
if (!err)
return err;
}

if (try_all_type & MTK_PULL_PULLSEL_TYPE) {
err = mtk_pinconf_bias_get_pullsel_pullen(hw, desc,
pullup, enable);
if (!err)
return err;
}

if (try_all_type & MTK_PULL_PUPD_R1R0_TYPE)
err = mtk_pinconf_bias_get_pupd_r1_r0(hw, desc, pullup, enable);

out:
return err;
}
EXPORT_SYMBOL_GPL(mtk_pinconf_bias_get_combo);
Expand Down
46 changes: 46 additions & 0 deletions drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -17,6 +17,22 @@
#define MTK_ENABLE 1
#define MTK_PULLDOWN 0
#define MTK_PULLUP 1
#define MTK_PULL_PU_PD_TYPE BIT(0)
#define MTK_PULL_PULLSEL_TYPE BIT(1)
#define MTK_PULL_PUPD_R1R0_TYPE BIT(2)
/* MTK_PULL_RSEL_TYPE can select resistance and can be
* turned on/off itself. But it can't be selected pull up/down
*/
#define MTK_PULL_RSEL_TYPE BIT(3)
/* MTK_PULL_PU_PD_RSEL_TYPE is a type which is controlled by
* MTK_PULL_PU_PD_TYPE and MTK_PULL_RSEL_TYPE.
*/
#define MTK_PULL_PU_PD_RSEL_TYPE (MTK_PULL_PU_PD_TYPE \
| MTK_PULL_RSEL_TYPE)
#define MTK_PULL_TYPE_MASK (MTK_PULL_PU_PD_TYPE |\
MTK_PULL_PULLSEL_TYPE |\
MTK_PULL_PUPD_R1R0_TYPE |\
MTK_PULL_RSEL_TYPE)

#define EINT_NA U16_MAX
#define NO_EINT_SUPPORT EINT_NA
Expand All @@ -42,6 +58,14 @@
PIN_FIELD_CALC(_s_pin, _e_pin, 0, _s_addr, _x_addrs, _s_bit, \
_x_bits, 32, 1)

#define PIN_RSEL(_s_pin, _e_pin, _rsel_index, _up_resl, _down_rsel) { \
.s_pin = _s_pin, \
.e_pin = _e_pin, \
.rsel_index = _rsel_index, \
.up_rsel = _up_resl, \
.down_rsel = _down_rsel, \
}

/* List these attributes which could be modified for the pin */
enum {
PINCTRL_PIN_REG_MODE,
Expand All @@ -67,6 +91,7 @@ enum {
PINCTRL_PIN_REG_DRV_E0,
PINCTRL_PIN_REG_DRV_E1,
PINCTRL_PIN_REG_DRV_ADV,
PINCTRL_PIN_REG_RSEL,
PINCTRL_PIN_REG_MAX,
};

Expand Down Expand Up @@ -129,6 +154,22 @@ struct mtk_pin_field_calc {
u8 fixed;
};

/**
* struct mtk_pin_rsel - the structure that provides bias resistance selection.
* @s_pin: the start pin within the rsel range
* @e_pin: the end pin within the rsel range
* @rsel_index: the rsel bias resistance index
* @up_rsel: the pullup rsel bias resistance value
* @down_rsel: the pulldown rsel bias resistance value
*/
struct mtk_pin_rsel {
u16 s_pin;
u16 e_pin;
u16 rsel_index;
u32 up_rsel;
u32 down_rsel;
};

/* struct mtk_pin_reg_calc - the structure that holds all ranges used to
* determine which register the pin would make use of
* for certain pin attribute.
Expand Down Expand Up @@ -206,6 +247,9 @@ struct mtk_pin_soc {
bool ies_present;
const char * const *base_names;
unsigned int nbase_names;
const unsigned int *pull_type;
const struct mtk_pin_rsel *pin_rsel;
unsigned int npin_rsel;

/* Specific pinconfig operations */
int (*bias_disable_set)(struct mtk_pinctrl *hw,
Expand Down Expand Up @@ -254,6 +298,8 @@ struct mtk_pinctrl {
const char **grp_names;
/* lock pin's register resource to avoid multiple threads issue*/
spinlock_t lock;
/* identify rsel setting by si unit or rsel define in dts node */
bool rsel_si_unit;
};

void mtk_rmw(struct mtk_pinctrl *pctl, u8 i, u32 reg, u32 mask, u32 set);
Expand Down
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