gpio: tc35894: Disable Direct KBD interrupts to enable gpio irq

On tc35894, have to disable direct keypad interrupts to make
it as general purpose interrupts functionality work.
if not, after chip reset, IRQST(0x91) will always 0x20,
IRQN always low level, can't be clear.

Configure DIRECTx to enable general purpose gpio mode,
else read GPIOMISx register always zero in irq routine.

verified on tc35894, need more test on other tc3589x.
Signed-off-by: dillon min <dillon.minfei@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpio-tc3589x.c

@@ -19,9 +19,9 @@
  * These registers are modified under the irq bus lock and cached to avoid
  * unnecessary writes in bus_sync_unlock.
  */
-enum { REG_IBE, REG_IEV, REG_IS, REG_IE };
+enum { REG_IBE, REG_IEV, REG_IS, REG_IE, REG_DIRECT };
 
-#define CACHE_NR_REGS	4
+#define CACHE_NR_REGS	5
 #define CACHE_NR_BANKS	3
 
 struct tc3589x_gpio {
@@ -200,6 +200,7 @@ static void tc3589x_gpio_irq_sync_unlock(struct irq_data *d)
 		[REG_IEV]	= TC3589x_GPIOIEV0,
 		[REG_IS]	= TC3589x_GPIOIS0,
 		[REG_IE]	= TC3589x_GPIOIE0,
+		[REG_DIRECT]	= TC3589x_DIRECT0,
 	};
 	int i, j;
 
@@ -228,6 +229,7 @@ static void tc3589x_gpio_irq_mask(struct irq_data *d)
 	int mask = BIT(offset % 8);
 
 	tc3589x_gpio->regs[REG_IE][regoffset] &= ~mask;
+	tc3589x_gpio->regs[REG_DIRECT][regoffset] |= mask;
 }
 
 static void tc3589x_gpio_irq_unmask(struct irq_data *d)
@@ -239,6 +241,7 @@ static void tc3589x_gpio_irq_unmask(struct irq_data *d)
 	int mask = BIT(offset % 8);
 
 	tc3589x_gpio->regs[REG_IE][regoffset] |= mask;
+	tc3589x_gpio->regs[REG_DIRECT][regoffset] &= ~mask;
 }
 
 static struct irq_chip tc3589x_gpio_irq_chip = {
@@ -334,6 +337,17 @@ static int tc3589x_gpio_probe(struct platform_device *pdev)
 	if (ret < 0)
 		return ret;
 
+	 /* For tc35894, have to disable Direct KBD interrupts,
+	  * else IRQST will always be 0x20, IRQN low level, can't
+	  * clear the irq status.
+	  * TODO: need more test on other tc3589x chip.
+	  *
+	  */
+	ret = tc3589x_reg_write(tc3589x, TC3589x_DKBDMSK,
+			TC3589x_DKBDMSK_ELINT | TC3589x_DKBDMSK_EINT);
+	if (ret < 0)
+		return ret;
+
 	ret = devm_request_threaded_irq(&pdev->dev,
 					irq, NULL, tc3589x_gpio_irq,
 					IRQF_ONESHOT, "tc3589x-gpio",

include/linux/mfd/tc3589x.h

@@ -19,6 +19,9 @@ enum tx3589x_block {
 #define TC3589x_RSTCTRL_KBDRST	(1 << 1)
 #define TC3589x_RSTCTRL_GPIRST	(1 << 0)
 
+#define TC3589x_DKBDMSK_ELINT	(1 << 1)
+#define TC3589x_DKBDMSK_EINT	(1 << 0)
+
 /* Keyboard Configuration Registers */
 #define TC3589x_KBDSETTLE_REG   0x01
 #define TC3589x_KBDBOUNCE       0x02
@@ -101,6 +104,9 @@ enum tx3589x_block {
 #define TC3589x_GPIOODM2	0xE4
 #define TC3589x_GPIOODE2	0xE5
 
+#define TC3589x_DIRECT0		0xEC
+#define TC3589x_DKBDMSK		0xF3
+
 #define TC3589x_INT_GPIIRQ	0
 #define TC3589x_INT_TI0IRQ	1
 #define TC3589x_INT_TI1IRQ	2