driver/ioexpander_it8801: add I/O expander driver for GPIO

IT8801 is an I/O expander with the gpio. Add api compatible with
ioexpander_drv so the main io expander framework can make use
of the pins on the it8801.

BUG=b/138352732, b/146996723
BRANCH=none
TEST=Use gpio.inc to declare the gpio state.
The console command #ioexget can get as follows:
  0  O L IT8801_G0_00
  1  O H IT8801_G0_03
  1  O H IT8801_G0_04
  0  O L IT8801_G0_06
  0  O L IT8801_G0_07
  1  O H ODR IT8801_G1_10
  1  O H ODR IT8801_G1_11
  1  O H ODR IT8801_G1_12
  1  I H IT8801_G1_13
  1  I H IT8801_G1_14
  1  I H IT8801_G1_15
  1  O H ODR IT8801_G2_20
  1  O H ODR IT8801_G2_21
  0  O L ODR IT8801_G2_22
  0  O L ODR IT8801_G2_23
TEST=jacuzzi, juniper and kappa still compile
TEST=keyboard scanning still works
TEST=keyboard scanning now uses fewer i2c packets due to caching of GPIO23

Change-Id: I7ad89058ccd43b073d648e93877b86d6f187b5df
Signed-off-by: tim <tim2.lin@ite.corp-partner.google.com>
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1712887
Reviewed-by: David Huang <David.Huang@quantatw.com>
Reviewed-by: Ting Shen <phoenixshen@chromium.org>
Tested-by: David Huang <David.Huang@quantatw.com>

1 files changed, 205 insertions, 16 deletions

diff --git a/driver/ioexpander/it8801.c b/driver/ioexpander/it8801.c
index 00e40e12ed..1226378c9a 100644
--- a/driver/ioexpander/it8801.c
+++ b/driver/ioexpander/it8801.c
@@ -7,6 +7,7 @@
 #include "console.h"
 #include "gpio.h"
 #include "i2c.h"
+#include "ioexpander.h"
 #include "it8801.h"
 #include "keyboard_raw.h"
 #include "keyboard_scan.h"
@@ -16,6 +17,8 @@
 
 #define CPRINTS(format, args...) cprints(CC_KEYSCAN, format, ## args)
 
+static int it8801_ioex_set_level(int ioex, int port, int mask, int value);
+
 static int it8801_read(int reg, int *data)
 {
 	return i2c_read8(I2C_PORT_IO_EXPANDER_IT8801, IT8801_I2C_ADDR,
@@ -58,7 +61,7 @@ static int it8801_check_vendor_id(void)
 
 void keyboard_raw_init(void)
 {
-	int ret, val;
+	int ret;
 
 	/*  Verify Vendor ID registers. */
 	ret = it8801_check_vendor_id();
@@ -84,8 +87,7 @@ void keyboard_raw_init(void)
 		it8801_write(IT8801_REG_GPIO23_KSO20, IT8801_REG_MASK_GPIODIR);
 
 		/* Start with KEYBOARD_COLUMN_ALL, output high(so selected). */
-		it8801_read(IT8801_REG_GPIOG2SOVR, &val);
-		it8801_write(IT8801_REG_GPIOG2SOVR, val | IT8801_REG_GPIO23SOV);
+		it8801_ioex_set_level(0, 2, IT8801_REG_GPIO23SOV, 1);
 	}
 
 	/* Keyboard scan in interrupt enable register */
@@ -113,7 +115,7 @@ BUILD_ASSERT(ARRAY_SIZE(kso_mapping) == KEYBOARD_COLS_MAX);
 
 test_mockable void keyboard_raw_drive_column(int col)
 {
-	int kso_val, val;
+	int kso_val;
 
 	/* Tri-state all outputs */
 	if (col == KEYBOARD_COLUMN_NONE) {
@@ -122,9 +124,7 @@ test_mockable void keyboard_raw_drive_column(int col)
 
 		if (IS_ENABLED(CONFIG_KEYBOARD_COL2_INVERTED)) {
 			/* Output low(so not selected). */
-			it8801_read(IT8801_REG_GPIOG2SOVR, &val);
-			it8801_write(IT8801_REG_GPIOG2SOVR, val &
-				~IT8801_REG_GPIO23SOV);
+			it8801_ioex_set_level(0, 2, IT8801_REG_GPIO23SOV, 0);
 		}
 	}
 	/* Assert all outputs */
@@ -134,9 +134,7 @@ test_mockable void keyboard_raw_drive_column(int col)
 
 		if (IS_ENABLED(CONFIG_KEYBOARD_COL2_INVERTED)) {
 			/* Output high(so selected). */
-			it8801_read(IT8801_REG_GPIOG2SOVR, &val);
-			it8801_write(IT8801_REG_GPIOG2SOVR, val |
-				IT8801_REG_GPIO23SOV);
+			it8801_ioex_set_level(0, 2, IT8801_REG_GPIO23SOV, 1);
 		}
 	} else {
 		/* To check if column is valid or not. */
@@ -152,14 +150,12 @@ test_mockable void keyboard_raw_drive_column(int col)
 			/* GPIO23 is inverted. */
 			if (col == IT8801_REG_MASK_SELKSO2) {
 				/* Output high(so selected). */
-				it8801_read(IT8801_REG_GPIOG2SOVR, &val);
-				it8801_write(IT8801_REG_GPIOG2SOVR, val |
-					IT8801_REG_GPIO23SOV);
+				it8801_ioex_set_level(0, 2,
+						IT8801_REG_GPIO23SOV, 1);
 			} else {
 				/* Output low(so not selected). */
-				it8801_read(IT8801_REG_GPIOG2SOVR, &val);
-				it8801_write(IT8801_REG_GPIOG2SOVR, val &
-					~IT8801_REG_GPIO23SOV);
+				it8801_ioex_set_level(0, 2,
+						IT8801_REG_GPIO23SOV, 0);
 			}
 		}
 	}
@@ -199,6 +195,199 @@ void io_expander_it8801_interrupt(enum gpio_signal signal)
 	task_wake(TASK_ID_KEYSCAN);
 }
 
+static int it8801_ioex_read(int ioex, int reg, int *data)
+{
+	struct ioexpander_config_t *ioex_p = &ioex_config[ioex];
+
+	return i2c_read8(ioex_p->i2c_host_port, ioex_p->i2c_slave_addr,
+			 reg, data);
+}
+
+static int it8801_ioex_write(int ioex, int reg, int data)
+{
+	struct ioexpander_config_t *ioex_p = &ioex_config[ioex];
+
+	return i2c_write8(ioex_p->i2c_host_port, ioex_p->i2c_slave_addr,
+			  reg, data);
+}
+
+/*
+ * Initialize the general purpose I/O port(GPIO)
+ */
+static int it8801_ioex_init(int ioex)
+{
+	int ret;
+
+	/*  Verify Vendor ID registers. */
+	ret = it8801_check_vendor_id();
+	if (ret) {
+		CPRINTS("Failed to read IT8801 vendor id %x", ret);
+		return ret;
+	}
+
+	return EC_SUCCESS;
+}
+
+static const int it8801_valid_gpio_group[] = {
+	IT8801_VALID_GPIO_G0_MASK,
+	IT8801_VALID_GPIO_G1_MASK,
+	IT8801_VALID_GPIO_G2_MASK,
+};
+
+/* Mutexes */
+static struct mutex ioex_mutex;
+
+static uint8_t it8801_gpio_sov[ARRAY_SIZE(it8801_valid_gpio_group)];
+
+static int ioex_check_is_not_valid(int port, int mask)
+{
+	if (port >= ARRAY_SIZE(it8801_valid_gpio_group)) {
+		CPRINTS("Port%d is not support in IT8801", port);
+		return EC_ERROR_INVAL;
+	}
+
+	if (mask & ~it8801_valid_gpio_group[port]) {
+		CPRINTS("GPIO%d-%d is not support in IT8801", port,
+			__fls(mask & ~it8801_valid_gpio_group[port]));
+		return EC_ERROR_INVAL;
+	}
+
+	return EC_SUCCESS;
+}
+
+static int it8801_ioex_get_level(int ioex, int port, int mask, int *val)
+{
+	int rv;
+
+	if (ioex_check_is_not_valid(port, mask))
+		return EC_ERROR_INVAL;
+
+	rv = it8801_ioex_read(ioex, IT8801_REG_GPIO_IPSR(port), val);
+
+	*val = !!(*val & mask);
+
+	return rv;
+}
+
+static int it8801_ioex_set_level(int ioex, int port, int mask, int value)
+{
+	int rv = EC_SUCCESS;
+
+	if (ioex_check_is_not_valid(port, mask))
+		return EC_ERROR_INVAL;
+
+	mutex_lock(&ioex_mutex);
+	/*
+	 * The bit of output value in SOV is different than
+	 * the one we were about to set it to.
+	 */
+	if (!!(it8801_gpio_sov[port] & mask) ^ value) {
+		if (value)
+			it8801_gpio_sov[port] |= mask;
+		else
+			it8801_gpio_sov[port] &= ~mask;
+
+		rv = it8801_ioex_write(ioex, IT8801_REG_GPIO_SOVR(port),
+						it8801_gpio_sov[port]);
+	}
+	mutex_unlock(&ioex_mutex);
+
+	return rv;
+}
+
+static int it8801_ioex_get_flags_by_mask(int ioex, int port,
+		int mask, int *flags)
+{
+	int rv, val;
+
+	if (ioex_check_is_not_valid(port, mask))
+		return EC_ERROR_INVAL;
+
+	rv = it8801_ioex_read(ioex, IT8801_REG_GPIO_CR(port, mask), &val);
+	if (rv)
+		return rv;
+
+	*flags = 0;
+
+	/* Get GPIO direction */
+	*flags |= (val & IT8801_GPIODIR) ? GPIO_OUTPUT : GPIO_INPUT;
+
+	/* Get GPIO type, 0:push-pull 1:open-drain */
+	if (val & IT8801_GPIOIOT)
+		*flags |= GPIO_OPEN_DRAIN;
+
+	rv = it8801_ioex_read(ioex, IT8801_REG_GPIO_IPSR(port), &val);
+	if (rv)
+		return rv;
+
+	/* Get GPIO output level */
+	*flags |= (val & mask) ? GPIO_HIGH : GPIO_LOW;
+
+	return EC_SUCCESS;
+}
+
+static int it8801_ioex_set_flags_by_mask(int ioex, int port,
+		int mask, int flags)
+{
+	int rv, val;
+
+	if (ioex_check_is_not_valid(port, mask))
+		return EC_ERROR_INVAL;
+
+	if (flags & ~IT8801_SUPPORT_GPIO_FLAGS) {
+		CPRINTS("Flag 0x%08x is not supported at port %d, mask %d",
+					flags, port, mask);
+		return EC_ERROR_INVAL;
+	}
+
+	/* GPIO alternate function switching(GPIO[00, 12:15, 20:23]). */
+	it8801_ioex_write(ioex, IT8801_REG_GPIO_CR(port, mask),
+					IT8801_REG_MASK_GPIOAFS_FUNC1);
+
+	mutex_lock(&ioex_mutex);
+	rv = it8801_ioex_read(ioex, IT8801_REG_GPIO_CR(port, mask), &val);
+	if (rv) {
+		mutex_unlock(&ioex_mutex);
+		return rv;
+	}
+	/* Select open drain 0:push-pull 1:open-drain */
+	if (flags & GPIO_OPEN_DRAIN)
+		val |= IT8801_GPIOIOT;
+	else
+		val &= ~IT8801_GPIOIOT;
+
+	/* Select GPIO direction */
+	if (flags & GPIO_OUTPUT) {
+		/* Configure the output level */
+		if (flags & GPIO_HIGH)
+			it8801_gpio_sov[port] |= mask;
+		else
+			it8801_gpio_sov[port] &= ~mask;
+
+		rv = it8801_ioex_write(ioex, IT8801_REG_GPIO_SOVR(port),
+						it8801_gpio_sov[port]);
+		if (rv) {
+			mutex_unlock(&ioex_mutex);
+			return rv;
+		}
+		val |= IT8801_GPIODIR;
+	} else
+		val &= ~IT8801_GPIODIR;
+
+	rv = it8801_ioex_write(ioex, IT8801_REG_GPIO_CR(port, mask), val);
+	mutex_unlock(&ioex_mutex);
+
+	return rv;
+}
+
+const struct ioexpander_drv it8801_ioexpander_drv = {
+	.init              = &it8801_ioex_init,
+	.get_level         = &it8801_ioex_get_level,
+	.set_level         = &it8801_ioex_set_level,
+	.get_flags_by_mask = &it8801_ioex_get_flags_by_mask,
+	.set_flags_by_mask = &it8801_ioex_set_flags_by_mask,
+};
+
 static void dump_register(int reg)
 {
 	int rv;