[PATCH v2 07/10] gpio: stmpe: rework registers access

From: patrice.chotard
Date: Thu Apr 28 2016 - 08:16:38 EST


From: Patrice Chotard <patrice.chotard@xxxxxx>

This update allows to use registers map as following :
regs[reg_index + offset] instead of
regs[reg_index] + offset

This makes code clearer and will facilitate the addition of STMPE1600
on which LSB and MSB registers are respectively located at addr and addr + 1.
Despite for all others STMPE variant, LSB and MSB registers are respectively
located in reverse order at addr + 1 and addr.

For variant which have 3 registers's bank, we use LSB,CSB and MSB indexes
which contains respectively LSB (or LOW), CSB (or MID) and MSB (or HIGH)
register addresses (STMPE1801/STMPE24xx).
For variant which have 2 registers's bank, we use LSB and CSB indexes only.
In this case the CSB index contains the MSB regs address (STMPE 1601).

Signed-off-by: Patrice Chotard <patrice.chotard@xxxxxx>
---
drivers/gpio/gpio-stmpe.c | 48 ++++++++++++++++++++++++++---------------------
1 file changed, 27 insertions(+), 21 deletions(-)

diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c
index 2789bdc..6d6d76a 100644
--- a/drivers/gpio/gpio-stmpe.c
+++ b/drivers/gpio/gpio-stmpe.c
@@ -21,6 +21,8 @@
*/
enum { REG_RE, REG_FE, REG_IE };

+enum { LSB, CSB, MSB };
+
#define CACHE_NR_REGS 3
/* No variant has more than 24 GPIOs */
#define CACHE_NR_BANKS (24 / 8)
@@ -40,7 +42,7 @@ static int stmpe_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
- u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB] - (offset / 8);
+ u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB + (offset / 8)];
u8 mask = 1 << (offset % 8);
int ret;

@@ -56,7 +58,7 @@ static void stmpe_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
int which = val ? STMPE_IDX_GPSR_LSB : STMPE_IDX_GPCR_LSB;
- u8 reg = stmpe->regs[which] - (offset / 8);
+ u8 reg = stmpe->regs[which + (offset / 8)];
u8 mask = 1 << (offset % 8);

/*
@@ -74,7 +76,7 @@ static int stmpe_gpio_direction_output(struct gpio_chip *chip,
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
- u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+ u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB + (offset / 8)];
u8 mask = 1 << (offset % 8);

stmpe_gpio_set(chip, offset, val);
@@ -87,7 +89,7 @@ static int stmpe_gpio_direction_input(struct gpio_chip *chip,
{
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
struct stmpe *stmpe = stmpe_gpio->stmpe;
- u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+ u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB + (offset / 8)];
u8 mask = 1 << (offset % 8);

return stmpe_set_bits(stmpe, reg, mask, 0);
@@ -157,10 +159,16 @@ static void stmpe_gpio_irq_sync_unlock(struct irq_data *d)
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
struct stmpe *stmpe = stmpe_gpio->stmpe;
int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
- static const u8 regmap[] = {
- [REG_RE] = STMPE_IDX_GPRER_LSB,
- [REG_FE] = STMPE_IDX_GPFER_LSB,
- [REG_IE] = STMPE_IDX_IEGPIOR_LSB,
+ static const u8 regmap[CACHE_NR_REGS][CACHE_NR_BANKS] = {
+ [REG_RE][LSB] = STMPE_IDX_GPRER_LSB,
+ [REG_RE][CSB] = STMPE_IDX_GPRER_CSB,
+ [REG_RE][MSB] = STMPE_IDX_GPRER_MSB,
+ [REG_FE][LSB] = STMPE_IDX_GPFER_LSB,
+ [REG_FE][CSB] = STMPE_IDX_GPFER_CSB,
+ [REG_FE][MSB] = STMPE_IDX_GPFER_MSB,
+ [REG_IE][LSB] = STMPE_IDX_IEGPIOR_LSB,
+ [REG_IE][CSB] = STMPE_IDX_IEGPIOR_CSB,
+ [REG_IE][MSB] = STMPE_IDX_IEGPIOR_MSB,
};
int i, j;

@@ -178,7 +186,7 @@ static void stmpe_gpio_irq_sync_unlock(struct irq_data *d)
continue;

stmpe_gpio->oldregs[i][j] = new;
- stmpe_reg_write(stmpe, stmpe->regs[regmap[i]] - j, new);
+ stmpe_reg_write(stmpe, stmpe->regs[regmap[i][j]], new);
}
}

@@ -214,9 +222,9 @@ static void stmpe_dbg_show_one(struct seq_file *s,
struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
struct stmpe *stmpe = stmpe_gpio->stmpe;
const char *label = gpiochip_is_requested(gc, offset);
- int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
bool val = !!stmpe_gpio_get(gc, offset);
- u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+ u8 bank = offset / 8;
+ u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB + bank];
u8 mask = 1 << (offset % 8);
int ret;
u8 dir;
@@ -257,18 +265,16 @@ static void stmpe_dbg_show_one(struct seq_file *s,
case STMPE1601:
case STMPE2401:
case STMPE2403:
- edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_MSB] +
- num_banks - 1 - (offset / 8);
+ edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_LSB + bank];
ret = stmpe_reg_read(stmpe, edge_det_reg);
if (ret < 0)
return;
edge_det = !!(ret & mask);

case STMPE1801:
- rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB] -
- (offset / 8);
- fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB] -
- (offset / 8);
+ rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB + bank];
+ fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB + bank];
+
ret = stmpe_reg_read(stmpe, rise_reg);
if (ret < 0)
return;
@@ -279,8 +285,7 @@ static void stmpe_dbg_show_one(struct seq_file *s,
fall = !!(ret & mask);

case STMPE801:
- irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB] -
- (offset / 8);
+ irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB + bank];
break;

default:
@@ -362,8 +367,9 @@ static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
*/
if (stmpe->partnum != STMPE801 || stmpe->partnum != STMPE1801) {
stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
- stmpe_reg_write(stmpe, stmpe->regs[STMPE_IDX_GPEDR_MSB]
- + i, status[i]);
+ stmpe_reg_write(stmpe,
+ stmpe->regs[STMPE_IDX_GPEDR_LSB + i],
+ status[i]);
}
}

--
1.9.1