[PATCH 08/14] pinctrl-sx150x: Replace sx150x_*_cfg by means of regmap API

From: Andrey Smirnov
Date: Tue Nov 01 2016 - 12:04:36 EST

The difference between 8 and 16 pin GPIO expanders can be accomodated by
the means of regmap API without resorting to usaing driver-specific
read/write accessors. This change, IMHO, brings the following benefits:

- Replaces driver's idiosyncratic way of dealing with
mult-register fields with regmap API, which, hopefuly,
makes the code a bit easier for a new reader to understand

- Removes various multi-read for-loop register read logic
from various places in the code and puts it in a signle
place

- Removes ad-hoc IRQ register caching code in
sx150x_irq_bus_sync_unlock, since that functionality is
provided by regmap

Besided aforementioned benefits this change also implements necessary
RegSense byte swap necessary for SX1503 and SX1506 variants of the chip.

Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
---
drivers/pinctrl/pinctrl-sx150x.c | 527 +++++++++++++++++++++------------------
1 file changed, 284 insertions(+), 243 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-sx150x.c b/drivers/pinctrl/pinctrl-sx150x.c
index 0e7c5fb..af0fc07 100644
--- a/drivers/pinctrl/pinctrl-sx150x.c
+++ b/drivers/pinctrl/pinctrl-sx150x.c
@@ -105,11 +105,8 @@ struct sx150x_pinctrl {
struct irq_chip irq_chip;
struct regmap *regmap;
struct {
- int update;
u32 sense;
u32 masked;
- u32 dev_sense;
- u32 dev_masked;
} irq;
struct mutex lock;
const struct sx150x_device_data *data;
@@ -170,16 +167,16 @@ static const struct sx150x_device_data sx1508q_device_data = {

static const struct sx150x_device_data sx1509q_device_data = {
.model = SX150X_789,
- .reg_pullup = 0x07,
- .reg_pulldn = 0x09,
- .reg_dir = 0x0f,
- .reg_data = 0x11,
- .reg_irq_mask = 0x13,
- .reg_irq_src = 0x19,
- .reg_sense = 0x17,
+ .reg_pullup = 0x06,
+ .reg_pulldn = 0x08,
+ .reg_dir = 0x0e,
+ .reg_data = 0x10,
+ .reg_irq_mask = 0x12,
+ .reg_irq_src = 0x18,
+ .reg_sense = 0x14,
.pri.x789 = {
- .reg_drain = 0x0b,
- .reg_polarity = 0x0d,
+ .reg_drain = 0x0a,
+ .reg_polarity = 0x0c,
.reg_clock = 0x1e,
.reg_misc = 0x1f,
.reg_reset = 0x7d,
@@ -191,20 +188,20 @@ static const struct sx150x_device_data sx1509q_device_data = {

static const struct sx150x_device_data sx1506q_device_data = {
.model = SX150X_456,
- .reg_pullup = 0x05,
- .reg_pulldn = 0x07,
- .reg_dir = 0x03,
- .reg_data = 0x01,
- .reg_irq_mask = 0x09,
- .reg_irq_src = 0x0f,
- .reg_sense = 0x0d,
+ .reg_pullup = 0x04,
+ .reg_pulldn = 0x06,
+ .reg_dir = 0x02,
+ .reg_data = 0x00,
+ .reg_irq_mask = 0x08,
+ .reg_irq_src = 0x0e,
+ .reg_sense = 0x0a,
.pri.x456 = {
- .reg_pld_mode = 0x21,
- .reg_pld_table0 = 0x23,
- .reg_pld_table1 = 0x25,
- .reg_pld_table2 = 0x27,
- .reg_pld_table3 = 0x29,
- .reg_pld_table4 = 0x2b,
+ .reg_pld_mode = 0x20,
+ .reg_pld_table0 = 0x22,
+ .reg_pld_table1 = 0x24,
+ .reg_pld_table2 = 0x26,
+ .reg_pld_table3 = 0x28,
+ .reg_pld_table4 = 0x2a,
.reg_advance = 0xad,
},
.ngpios = 16,
@@ -237,20 +234,20 @@ static const struct sx150x_device_data sx1502q_device_data = {

static const struct sx150x_device_data sx1503q_device_data = {
.model = SX150X_123,
- .reg_pullup = 0x05,
- .reg_pulldn = 0x07,
- .reg_dir = 0x03,
- .reg_data = 0x01,
- .reg_irq_mask = 0x09,
- .reg_irq_src = 0x0f,
- .reg_sense = 0x07,
+ .reg_pullup = 0x04,
+ .reg_pulldn = 0x06,
+ .reg_dir = 0x02,
+ .reg_data = 0x00,
+ .reg_irq_mask = 0x08,
+ .reg_irq_src = 0x0e,
+ .reg_sense = 0x0a,
.pri.x123 = {
- .reg_pld_mode = 0x10,
- .reg_pld_table0 = 0x11,
- .reg_pld_table1 = 0x12,
- .reg_pld_table2 = 0x13,
- .reg_pld_table3 = 0x14,
- .reg_pld_table4 = 0x15,
+ .reg_pld_mode = 0x20,
+ .reg_pld_table0 = 0x22,
+ .reg_pld_table1 = 0x24,
+ .reg_pld_table2 = 0x26,
+ .reg_pld_table3 = 0x28,
+ .reg_pld_table4 = 0x2a,
.reg_advance = 0xad,
},
.ngpios = 16,
@@ -258,70 +255,6 @@ static const struct sx150x_device_data sx1503q_device_data = {
.npins = 16, /* oscio not available */
};

-/*
- * These utility functions solve the common problem of locating and setting
- * configuration bits. Configuration bits are grouped into registers
- * whose indexes increase downwards. For example, with eight-bit registers,
- * sixteen gpios would have their config bits grouped in the following order:
- * REGISTER N-1 [ f e d c b a 9 8 ]
- * N [ 7 6 5 4 3 2 1 0 ]
- *
- * For multi-bit configurations, the pattern gets wider:
- * REGISTER N-3 [ f f e e d d c c ]
- * N-2 [ b b a a 9 9 8 8 ]
- * N-1 [ 7 7 6 6 5 5 4 4 ]
- * N [ 3 3 2 2 1 1 0 0 ]
- *
- * Given the address of the starting register 'N', the index of the gpio
- * whose configuration we seek to change, and the width in bits of that
- * configuration, these functions allow us to locate the correct
- * register and mask the correct bits.
- */
-static inline void sx150x_find_cfg(u8 offset, u8 width,
- u8 *reg, u8 *mask, u8 *shift)
-{
- *reg -= offset * width / 8;
- *mask = (1 << width) - 1;
- *shift = (offset * width) % 8;
- *mask <<= *shift;
-}
-
-static int sx150x_write_cfg(struct i2c_client *client,
- u8 offset, u8 width, u8 reg, u8 val)
-{
- u8 mask;
- unsigned int data;
- u8 shift;
- int err;
- struct sx150x_pinctrl *pctl = i2c_get_clientdata(client);
-
- sx150x_find_cfg(offset, width, &reg, &mask, &shift);
- err = regmap_read(pctl->regmap, reg, &data);
- if (err < 0)
- return err;
-
- data &= ~mask;
- data |= (val << shift) & mask;
- return regmap_write(pctl->regmap, reg, data);
-}
-
-static int sx150x_read_cfg(struct i2c_client *client,
- u8 offset, u8 width, u8 reg)
-{
- u8 mask;
- unsigned int data;
- u8 shift;
- int err;
- struct sx150x_pinctrl *pctl = i2c_get_clientdata(client);
-
- sx150x_find_cfg(offset, width, &reg, &mask, &shift);
- err = regmap_read(pctl->regmap, reg, &data);
- if (err < 0)
- return err;
-
- return (data & mask);
-}
-
static int sx150x_pinctrl_get_groups_count(struct pinctrl_dev *pctldev)
{
return 0;
@@ -367,31 +300,33 @@ static int sx150x_gpio_get_direction(struct gpio_chip *chip,
unsigned int offset)
{
struct sx150x_pinctrl *pctl = gpiochip_get_data(chip);
- int status;
+ unsigned int value;
+ int ret;

if (sx150x_pin_is_oscio(pctl, offset))
return false;

- status = sx150x_read_cfg(pctl->client, offset, 1, pctl->data->reg_dir);
- if (status >= 0)
- status = !!status;
+ ret = regmap_read(pctl->regmap, pctl->data->reg_dir, &value);
+ if (ret < 0)
+ return ret;

- return status;
+ return !!(value & BIT(offset));
}

static int sx150x_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct sx150x_pinctrl *pctl = gpiochip_get_data(chip);
- int status;
+ unsigned int value;
+ int ret;

if (sx150x_pin_is_oscio(pctl, offset))
return -EINVAL;

- status = sx150x_read_cfg(pctl->client, offset, 1, pctl->data->reg_data);
- if (status >= 0)
- status = !!status;
+ ret = regmap_read(pctl->regmap, pctl->data->reg_data, &value);
+ if (ret < 0)
+ return ret;

- return status;
+ return !!(value & BIT(offset));
}

static int sx150x_gpio_set_single_ended(struct gpio_chip *chip,
@@ -408,9 +343,9 @@ static int sx150x_gpio_set_single_ended(struct gpio_chip *chip,
return 0;

mutex_lock(&pctl->lock);
- ret = sx150x_write_cfg(pctl->client, offset, 1,
- pctl->data->pri.x789.reg_drain,
- 0);
+ ret = regmap_write_bits(pctl->regmap,
+ pctl->data->pri.x789.reg_drain,
+ BIT(offset), 0);
mutex_unlock(&pctl->lock);
if (ret < 0)
return ret;
@@ -422,9 +357,9 @@ static int sx150x_gpio_set_single_ended(struct gpio_chip *chip,
return -ENOTSUPP;

mutex_lock(&pctl->lock);
- ret = sx150x_write_cfg(pctl->client, offset, 1,
- pctl->data->pri.x789.reg_drain,
- 1);
+ ret = regmap_write_bits(pctl->regmap,
+ pctl->data->pri.x789.reg_drain,
+ BIT(offset), BIT(offset));
mutex_unlock(&pctl->lock);
if (ret < 0)
return ret;
@@ -437,6 +372,13 @@ static int sx150x_gpio_set_single_ended(struct gpio_chip *chip,
return 0;
}

+static int __sx150x_gpio_set(struct sx150x_pinctrl *pctl, unsigned int offset,
+ int value)
+{
+ return regmap_write_bits(pctl->regmap, pctl->data->reg_data,
+ BIT(offset), value ? BIT(offset) : 0);
+}
+
static void sx150x_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
@@ -450,9 +392,7 @@ static void sx150x_gpio_set(struct gpio_chip *chip, unsigned int offset,
mutex_unlock(&pctl->lock);
} else {
mutex_lock(&pctl->lock);
- sx150x_write_cfg(pctl->client, offset, 1,
- pctl->data->reg_data,
- (value ? 1 : 0));
+ __sx150x_gpio_set(pctl, offset, value);
mutex_unlock(&pctl->lock);
}
}
@@ -467,8 +407,9 @@ static int sx150x_gpio_direction_input(struct gpio_chip *chip,
return -EINVAL;

mutex_lock(&pctl->lock);
- ret = sx150x_write_cfg(pctl->client, offset, 1,
- pctl->data->reg_dir, 1);
+ ret = regmap_write_bits(pctl->regmap,
+ pctl->data->reg_dir,
+ BIT(offset), BIT(offset));
mutex_unlock(&pctl->lock);

return ret;
@@ -486,12 +427,11 @@ static int sx150x_gpio_direction_output(struct gpio_chip *chip,
}

mutex_lock(&pctl->lock);
- status = sx150x_write_cfg(pctl->client, offset, 1,
- pctl->data->reg_data,
- (value ? 1 : 0));
+ status = __sx150x_gpio_set(pctl, offset, value);
if (status >= 0)
- status = sx150x_write_cfg(pctl->client, offset, 1,
- pctl->data->reg_dir, 0);
+ status = regmap_write_bits(pctl->regmap,
+ pctl->data->reg_dir,
+ BIT(offset), 0);
mutex_unlock(&pctl->lock);

return status;
@@ -503,8 +443,7 @@ static void sx150x_irq_mask(struct irq_data *d)
gpiochip_get_data(irq_data_get_irq_chip_data(d));
unsigned int n = d->hwirq;

- pctl->irq.masked |= (1 << n);
- pctl->irq.update = n;
+ pctl->irq.masked |= BIT(n);
}

static void sx150x_irq_unmask(struct irq_data *d)
@@ -513,8 +452,7 @@ static void sx150x_irq_unmask(struct irq_data *d)
gpiochip_get_data(irq_data_get_irq_chip_data(d));
unsigned int n = d->hwirq;

- pctl->irq.masked &= ~(1 << n);
- pctl->irq.update = n;
+ pctl->irq.masked &= ~BIT(n);
}

static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)
@@ -535,7 +473,6 @@ static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type)

pctl->irq.sense &= ~(3UL << (n * 2));
pctl->irq.sense |= val << (n * 2);
- pctl->irq.update = n;
return 0;
}

@@ -547,29 +484,20 @@ static irqreturn_t sx150x_irq_thread_fn(int irq, void *dev_id)
unsigned int n;
s32 err;
unsigned int val;
- int i;

- for (i = (pctl->data->ngpios / 8) - 1; i >= 0; --i) {
- err = regmap_read(pctl->regmap,
- pctl->data->reg_irq_src - i,
- &val);
- if (err < 0)
- continue;
+ err = regmap_read(pctl->regmap, pctl->data->reg_irq_src, &val);
+ if (err < 0)
+ return IRQ_NONE;

- err = regmap_write(pctl->regmap,
- pctl->data->reg_irq_src - i,
- val);
- if (err < 0)
- continue;
-
- for (n = 0; n < 8; ++n) {
- if (val & (1 << n)) {
- sub_irq = irq_find_mapping(
- pctl->gpio.irqdomain,
- (i * 8) + n);
- handle_nested_irq(sub_irq);
- ++nhandled;
- }
+ err = regmap_write(pctl->regmap, pctl->data->reg_irq_src, val);
+ if (err < 0)
+ return IRQ_NONE;
+
+ for (n = 0; n < pctl->data->ngpios; ++n) {
+ if (val & BIT(n)) {
+ sub_irq = irq_find_mapping(pctl->gpio.irqdomain, n);
+ handle_nested_irq(sub_irq);
+ ++nhandled;
}
}

@@ -588,35 +516,9 @@ static void sx150x_irq_bus_sync_unlock(struct irq_data *d)
{
struct sx150x_pinctrl *pctl =
gpiochip_get_data(irq_data_get_irq_chip_data(d));
- unsigned int n;
-
- if (pctl->irq.update < 0)
- goto out;

- n = pctl->irq.update;
- pctl->irq.update = -1;
-
- /* Avoid updates if nothing changed */
- if (pctl->irq.dev_sense == pctl->irq.sense &&
- pctl->irq.dev_masked == pctl->irq.masked)
- goto out;
-
- pctl->irq.dev_sense = pctl->irq.sense;
- pctl->irq.dev_masked = pctl->irq.masked;
-
- if (pctl->irq.masked & (1 << n)) {
- sx150x_write_cfg(pctl->client, n, 1,
- pctl->data->reg_irq_mask, 1);
- sx150x_write_cfg(pctl->client, n, 2,
- pctl->data->reg_sense, 0);
- } else {
- sx150x_write_cfg(pctl->client, n, 1,
- pctl->data->reg_irq_mask, 0);
- sx150x_write_cfg(pctl->client, n, 2,
- pctl->data->reg_sense,
- pctl->irq.sense >> (n * 2));
- }
-out:
+ regmap_write(pctl->regmap, pctl->data->reg_irq_mask, pctl->irq.masked);
+ regmap_write(pctl->regmap, pctl->data->reg_sense, pctl->irq.sense);
mutex_unlock(&pctl->lock);
}

@@ -627,10 +529,9 @@ static int sx150x_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
unsigned int param = pinconf_to_config_param(*config);
int ret;
u32 arg;
+ unsigned int data;

if (sx150x_pin_is_oscio(pctl, pin)) {
- unsigned int data;
-
switch (param) {
case PIN_CONFIG_DRIVE_PUSH_PULL:
case PIN_CONFIG_OUTPUT:
@@ -665,8 +566,10 @@ static int sx150x_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
switch (param) {
case PIN_CONFIG_BIAS_PULL_DOWN:
mutex_lock(&pctl->lock);
- ret = sx150x_read_cfg(pctl->client, pin, 1,
- pctl->data->reg_pulldn);
+ ret = regmap_read(pctl->regmap,
+ pctl->data->reg_pulldn,
+ &data);
+ data &= BIT(pin);
mutex_unlock(&pctl->lock);

if (ret < 0)
@@ -680,8 +583,10 @@ static int sx150x_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,

case PIN_CONFIG_BIAS_PULL_UP:
mutex_lock(&pctl->lock);
- ret = sx150x_read_cfg(pctl->client, pin, 1,
- pctl->data->reg_pullup);
+ ret = regmap_read(pctl->regmap,
+ pctl->data->reg_pullup,
+ &data);
+ data &= BIT(pin);
mutex_unlock(&pctl->lock);

if (ret < 0)
@@ -698,14 +603,16 @@ static int sx150x_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
return -ENOTSUPP;

mutex_lock(&pctl->lock);
- ret = sx150x_read_cfg(pctl->client, pin, 1,
- pctl->data->pri.x789.reg_drain);
+ ret = regmap_read(pctl->regmap,
+ pctl->data->pri.x789.reg_drain,
+ &data);
+ data &= BIT(pin);
mutex_unlock(&pctl->lock);

if (ret < 0)
return ret;

- if (!ret)
+ if (!data)
return -EINVAL;

arg = 1;
@@ -716,14 +623,16 @@ static int sx150x_pinconf_get(struct pinctrl_dev *pctldev, unsigned int pin,
arg = true;
else {
mutex_lock(&pctl->lock);
- ret = sx150x_read_cfg(pctl->client, pin, 1,
- pctl->data->pri.x789.reg_drain);
+ ret = regmap_read(pctl->regmap,
+ pctl->data->pri.x789.reg_drain,
+ &data);
+ data &= BIT(pin);
mutex_unlock(&pctl->lock);

if (ret < 0)
return ret;

- if (ret)
+ if (data)
return -EINVAL;

arg = 1;
@@ -784,15 +693,17 @@ static int sx150x_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,
case PIN_CONFIG_BIAS_PULL_PIN_DEFAULT:
case PIN_CONFIG_BIAS_DISABLE:
mutex_lock(&pctl->lock);
- ret = sx150x_write_cfg(pctl->client, pin, 1,
- pctl->data->reg_pulldn, 0);
+ ret = regmap_write_bits(pctl->regmap,
+ pctl->data->reg_pulldn,
+ BIT(pin), 0);
mutex_unlock(&pctl->lock);
if (ret < 0)
return ret;

mutex_lock(&pctl->lock);
- ret = sx150x_write_cfg(pctl->client, pin, 1,
- pctl->data->reg_pullup, 0);
+ ret = regmap_write_bits(pctl->regmap,
+ pctl->data->reg_pullup,
+ BIT(pin), 0);
mutex_unlock(&pctl->lock);
if (ret < 0)
return ret;
@@ -801,9 +712,9 @@ static int sx150x_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,

case PIN_CONFIG_BIAS_PULL_UP:
mutex_lock(&pctl->lock);
- ret = sx150x_write_cfg(pctl->client, pin, 1,
- pctl->data->reg_pullup,
- 1);
+ ret = regmap_write_bits(pctl->regmap,
+ pctl->data->reg_pullup,
+ BIT(pin), BIT(pin));
mutex_unlock(&pctl->lock);
if (ret < 0)
return ret;
@@ -812,9 +723,9 @@ static int sx150x_pinconf_set(struct pinctrl_dev *pctldev, unsigned int pin,

case PIN_CONFIG_BIAS_PULL_DOWN:
mutex_lock(&pctl->lock);
- ret = sx150x_write_cfg(pctl->client, pin, 1,
- pctl->data->reg_pulldn,
- 1);
+ ret = regmap_write_bits(pctl->regmap,
+ pctl->data->reg_pulldn,
+ BIT(pin), BIT(pin));
mutex_unlock(&pctl->lock);
if (ret < 0)
return ret;
@@ -868,16 +779,6 @@ static const struct i2c_device_id sx150x_id[] = {
{}
};

-static int sx150x_init_io(struct sx150x_pinctrl *pctl, u8 base, u16 cfg)
-{
- int err = 0;
- unsigned int n;
-
- for (n = 0; err >= 0 && n < (pctl->data->ngpios / 8); ++n)
- err = regmap_write(pctl->regmap, base - n, cfg >> (n * 8));
- return err;
-}
-
static int sx150x_reset(struct sx150x_pinctrl *pctl)
{
int err;
@@ -923,11 +824,16 @@ static int sx150x_init_misc(struct sx150x_pinctrl *pctl)
return -EINVAL;
}

- return i2c_smbus_write_byte_data(pctl->client, reg, value);
+ return regmap_write(pctl->regmap, reg, value);
}

static int sx150x_init_hw(struct sx150x_pinctrl *pctl)
{
+ const u8 reg[] = {
+ [SX150X_789] = pctl->data->pri.x789.reg_polarity,
+ [SX150X_456] = pctl->data->pri.x456.reg_pld_mode,
+ [SX150X_123] = pctl->data->pri.x123.reg_pld_mode,
+ };
int err;

if (pctl->data->model == SX150X_789 &&
@@ -942,28 +848,165 @@ static int sx150x_init_hw(struct sx150x_pinctrl *pctl)
return err;

/* Set all pins to work in normal mode */
- if (pctl->data->model == SX150X_789) {
- err = sx150x_init_io(pctl,
- pctl->data->pri.x789.reg_polarity,
- 0);
- if (err < 0)
- return err;
- } else if (pctl->data->model == SX150X_456) {
- /* Set all pins to work in normal mode */
- err = sx150x_init_io(pctl,
- pctl->data->pri.x456.reg_pld_mode,
- 0);
- if (err < 0)
- return err;
+ return regmap_write(pctl->regmap, reg[pctl->data->model], 0);
+}
+
+static int sx150x_regmap_reg_width(struct sx150x_pinctrl *pctl,
+ unsigned int reg)
+{
+ const struct sx150x_device_data *data = pctl->data;
+
+ if (reg == data->reg_sense) {
+ /*
+ * RegSense packs two bits of configuration per GPIO,
+ * so we'd need to read twice as many bits as there
+ * are GPIO in our chip
+ */
+ return 2 * data->ngpios;
+ } else if ((data->model == SX150X_789 &&
+ (reg == data->pri.x789.reg_misc ||
+ reg == data->pri.x789.reg_clock ||
+ reg == data->pri.x789.reg_reset))
+ ||
+ (data->model == SX150X_123 &&
+ reg == data->pri.x123.reg_advance)
+ ||
+ (data->model == SX150X_456 &&
+ reg == data->pri.x456.reg_advance)) {
+ return 8;
} else {
- /* Set all pins to work in normal mode */
- err = sx150x_init_io(pctl,
- pctl->data->pri.x123.reg_pld_mode,
- 0);
- if (err < 0)
- return err;
+ return data->ngpios;
+ }
+}
+
+static unsigned int sx150x_maybe_swizzle(struct sx150x_pinctrl *pctl,
+ unsigned int reg, unsigned int val)
+{
+ unsigned int a, b;
+ const struct sx150x_device_data *data = pctl->data;
+
+ /*
+ * Whereas SX1509 presents RegSense in a simple layout as such:
+ * reg [ f f e e d d c c ]
+ * reg + 1 [ b b a a 9 9 8 8 ]
+ * reg + 2 [ 7 7 6 6 5 5 4 4 ]
+ * reg + 3 [ 3 3 2 2 1 1 0 0 ]
+ *
+ * SX1503 and SX1506 deviate from that data layout, instead storing
+ * thier contents as follows:
+ *
+ * reg [ f f e e d d c c ]
+ * reg + 1 [ 7 7 6 6 5 5 4 4 ]
+ * reg + 2 [ b b a a 9 9 8 8 ]
+ * reg + 3 [ 3 3 2 2 1 1 0 0 ]
+ *
+ * so, taking that into account, we swap two
+ * inner bytes of a 4-byte result
+ */
+
+ if (reg == data->reg_sense &&
+ data->ngpios == 16 &&
+ (data->model == SX150X_123 ||
+ data->model == SX150X_456)) {
+ a = val & 0x00ff0000;
+ b = val & 0x0000ff00;
+
+ val &= 0xff0000ff;
+ val |= b << 8;
+ val |= a >> 8;
}

+ return val;
+}
+
+/*
+ * In order to mask the differences between 16 and 8 bit expander
+ * devices we set up a sligthly ficticious regmap that pretends to be
+ * a set of 32-bit (to accomodate RegSenseLow/RegSenseHigh
+ * pair/quartet) registers and transparently reconstructs those
+ * registers via multiple I2C/SMBus reads
+ *
+ * This way the rest of the driver code, interfacing with the chip via
+ * regmap API, can work assuming that each GPIO pin is represented by
+ * a group of bits at an offset proportioan to GPIO number within a
+ * given register.
+ *
+ */
+static int sx150x_regmap_reg_read(void *context, unsigned int reg,
+ unsigned int *result)
+{
+ int ret, n;
+ struct sx150x_pinctrl *pctl = context;
+ struct i2c_client *i2c = pctl->client;
+ const int width = sx150x_regmap_reg_width(pctl, reg);
+ unsigned int idx, val;
+
+ /*
+ * There are four potential cases coverd by this function:
+ *
+ * 1) 8-pin chip, single configuration bit register
+ *
+ * This is trivial the code below just needs to read:
+ * reg [ 7 6 5 4 3 2 1 0 ]
+ *
+ * 2) 8-pin chip, double configuration bit register (RegSense)
+ *
+ * The read will be done as follows:
+ * reg [ 7 7 6 6 5 5 4 4 ]
+ * reg + 1 [ 3 3 2 2 1 1 0 0 ]
+ *
+ * 3) 16-pin chip, single configuration bit register
+ *
+ * The read will be done as follows:
+ * reg [ f e d c b a 9 8 ]
+ * reg + 1 [ 7 6 5 4 3 2 1 0 ]
+ *
+ * 4) 16-pin chip, double configuration bit register (RegSense)
+ *
+ * The read will be done as follows:
+ * reg [ f f e e d d c c ]
+ * reg + 1 [ b b a a 9 9 8 8 ]
+ * reg + 2 [ 7 7 6 6 5 5 4 4 ]
+ * reg + 3 [ 3 3 2 2 1 1 0 0 ]
+ */
+
+ for (n = width, val = 0, idx = reg; n > 0; n -= 8, idx++) {
+ val <<= 8;
+
+ ret = i2c_smbus_read_byte_data(i2c, idx);
+ if (ret < 0)
+ return ret;
+
+ val |= ret;
+ }
+
+ *result = sx150x_maybe_swizzle(pctl, reg, val);
+
+ return 0;
+}
+
+static int sx150x_regmap_reg_write(void *context, unsigned int reg,
+ unsigned int val)
+{
+ int ret, n;
+ struct sx150x_pinctrl *pctl = context;
+ struct i2c_client *i2c = pctl->client;
+ const int width = sx150x_regmap_reg_width(pctl, reg);
+
+ val = sx150x_maybe_swizzle(pctl, reg, val);
+
+ n = width - 8;
+ do {
+ const u8 byte = (val >> n) & 0xff;
+
+ ret = i2c_smbus_write_byte_data(i2c, reg, byte);
+ if (ret < 0)
+ return ret;
+
+ reg++;
+ n -= 8;
+ } while (n >= 0);
+
return 0;
}

@@ -971,18 +1014,18 @@ static bool sx150x_reg_volatile(struct device *dev, unsigned int reg)
{
struct sx150x_pinctrl *pctl = i2c_get_clientdata(to_i2c_client(dev));

- return reg == pctl->data->reg_irq_src ||
- reg == pctl->data->reg_irq_src - 1 ||
- reg == pctl->data->reg_data ||
- reg == pctl->data->reg_data - 1;
+ return reg == pctl->data->reg_irq_src || reg == pctl->data->reg_data;
}

const struct regmap_config sx150x_regmap_config = {
.reg_bits = 8,
- .val_bits = 8,
+ .val_bits = 32,

.cache_type = REGCACHE_RBTREE,

+ .reg_read = sx150x_regmap_reg_read,
+ .reg_write = sx150x_regmap_reg_write,
+
.max_register = SX150X_MAX_REGISTER,
.volatile_reg = sx150x_reg_volatile,
};
@@ -1012,7 +1055,8 @@ static int sx150x_probe(struct i2c_client *client,
pctl->client = client;
pctl->data = (void *)id->driver_data;

- pctl->regmap = devm_regmap_init_i2c(client, &sx150x_regmap_config);
+ pctl->regmap = devm_regmap_init(dev, NULL, pctl,
+ &sx150x_regmap_config);
if (IS_ERR(pctl->regmap)) {
ret = PTR_ERR(pctl->regmap);
dev_err(dev, "Failed to allocate register map: %d\n",
@@ -1058,9 +1102,6 @@ static int sx150x_probe(struct i2c_client *client,

pctl->irq.masked = ~0;
pctl->irq.sense = 0;
- pctl->irq.dev_masked = ~0;
- pctl->irq.dev_sense = 0;
- pctl->irq.update = -1;

ret = gpiochip_irqchip_add(&pctl->gpio,
&pctl->irq_chip, 0,
--
2.5.5