IO_Expander: introduce the common interface of IO expander

Implement the common code to provide a friendly interface to control the
IOs of IO expander. It adopts a similar concept to GPIO.

1. Define the IO expander IO in gpio.inc by the format:
    IOEX(name, EXPIN(ioex, port, offset), flags)
    - name: the name of this IO pin
    - EXPIN(ioex, port, offset)
        - ioex: the IO expander port (defined in board.c) this IO
                     pin belongs to.
        - port: the port number in the IO expander chip.
	- offset: the bit offset in the port above.
    - flags: the same as the flags of GPIO.

2. The following APIs are supported:
    1. ioex_get_flags_by_mask
    2. ioex_set_flags_by_mask
    3. ioex_get_flags
    4. ioex_set_flags
    5. ioex_get_level
    6. ioex_set_level
    7. ioex_init

3. The following console commands are supported:
    1. ioexget [IO_EXPANDER_PIN_NAME]
    2. ioexset IO_EXPANDER_PIN_NAME 0/1

BRANCH=none
BUG=none
TEST=No error for "make buildall"
TEST=Apply this and related CLs, manually test each API, make sure each
function works correctly with IO expander chip (NCT3807/NCT3808.)

Change-Id: I79c9813abccc67d5554e2ceb5c119dcf549b7dce
Signed-off-by: CHLin <CHLIN56@nuvoton.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1657858
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Commit-Queue: CH Lin <chlin56@nuvoton.com>
Commit-Queue: Aseda Aboagye <aaboagye@chromium.org>
Tested-by: CH Lin <chlin56@nuvoton.com>

1 files changed, 221 insertions, 0 deletions

diff --git a/common/ioexpander.c b/common/ioexpander.c
new file mode 100644
index 0000000000..8e00f9337a
--- /dev/null
+++ b/common/ioexpander.c
@@ -0,0 +1,221 @@
+/* Copyright 2019 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* IO Expander Controller Common Code */
+
+#include "console.h"
+#include "gpio.h"
+#include "hooks.h"
+#include "ioexpander.h"
+#include "util.h"
+
+#define CPRINTF(format, args...) cprintf(CC_GPIO, format, ## args)
+#define CPRINTS(format, args...) cprints(CC_GPIO, format, ## args)
+
+static uint8_t last_val[(IOEX_COUNT + 7) / 8];
+
+static int last_val_changed(int i, int v)
+{
+	if (v && !(last_val[i / 8] & (BIT(i % 8)))) {
+		last_val[i / 8] |= BIT(i % 8);
+		return 1;
+	} else if (!v && last_val[i / 8] & (BIT(i % 8))) {
+		last_val[i / 8] &= ~(BIT(i % 8));
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+int ioex_get_flags_by_mask(int ioex, int port, int mask, int *flags)
+{
+	return ioex_config[ioex].drv->get_flags_by_mask(ioex, port, mask,
+							flags);
+}
+
+int ioex_set_flags_by_mask(int ioex, int port, int mask, int flags)
+{
+	return ioex_config[ioex].drv->set_flags_by_mask(ioex, port, mask,
+							flags);
+}
+
+int ioex_get_flags(enum ioex_signal signal, int *flags)
+{
+	const struct ioex_info *g = ioex_list + signal;
+
+	return ioex_config[g->ioex].drv->get_flags_by_mask(g->ioex,
+						g->port, g->mask, flags);
+}
+
+int ioex_set_flags(enum ioex_signal signal, int flags)
+{
+	const struct ioex_info *g = ioex_list + signal;
+
+	return ioex_config[g->ioex].drv->set_flags_by_mask(g->ioex,
+						g->port, g->mask, flags);
+}
+
+int ioex_get_level(enum ioex_signal signal, int *val)
+{
+	const struct ioex_info *g = ioex_list + signal;
+
+	return ioex_config[g->ioex].drv->get_level(g->ioex, g->port,
+							g->mask, val);
+}
+
+int ioex_set_level(enum ioex_signal signal, int value)
+{
+	const struct ioex_info *g = ioex_list + signal;
+
+	return ioex_config[g->ioex].drv->set_level(g->ioex, g->port,
+							g->mask, value);
+}
+
+int ioex_init(int ioex)
+{
+	const struct ioexpander_drv *drv = ioex_config[ioex].drv;
+
+	if (drv->init == NULL)
+		return EC_SUCCESS;
+
+	return  drv->init(ioex);
+}
+
+static void ioex_init_default(void)
+{
+	const struct ioex_info *g = ioex_list;
+	int i;
+
+	for (i = 0; i < CONFIG_IO_EXPANDER_PORT_COUNT; i++)
+		ioex_init(i);
+	/*
+	 * Set all IO expander GPIOs to default flags according to the setting
+	 * in gpio.inc
+	 */
+	for (i = 0; i < IOEX_COUNT; i++, g++) {
+		if (g->mask && !(g->flags & GPIO_DEFAULT)) {
+			ioex_set_flags_by_mask(g->ioex, g->port,
+						g->mask, g->flags);
+		}
+	}
+
+}
+DECLARE_HOOK(HOOK_INIT, ioex_init_default, HOOK_PRIO_INIT_I2C + 1);
+
+const char *ioex_get_name(enum ioex_signal signal)
+{
+	return ioex_list[signal].name;
+}
+
+static void print_ioex_info(int io)
+{
+	int changed, v, val;
+	int flags = 0;
+
+	v = ioex_get_level(io, &val);
+	if (v) {
+		ccprintf("Fail to get %s level\n", ioex_get_name(io));
+		return;
+	}
+	v = ioex_get_flags(io, &flags);
+	if (v) {
+		ccprintf("Fail to get %s flags\n", ioex_get_name(io));
+		return;
+	}
+
+	changed = last_val_changed(io, val);
+
+	ccprintf("  %d%c %s%s%s%s%s%s\n", val,
+		 (changed ? '*' : ' '),
+		 (flags & GPIO_INPUT ? "I " : ""),
+		 (flags & GPIO_OUTPUT ? "O " : ""),
+		 (flags & GPIO_LOW ? "L " : ""),
+		 (flags & GPIO_HIGH ? "H " : ""),
+		 (flags & GPIO_OPEN_DRAIN ? "ODR " : ""),
+		ioex_get_name(io));
+
+	/* Flush console to avoid truncating output */
+	cflush();
+}
+
+int ioex_get_default_flags(enum ioex_signal signal)
+{
+	return ioex_list[signal].flags;
+}
+
+/* IO expander commands */
+static enum ioex_signal find_ioex_by_name(const char *name)
+{
+	int i;
+
+	if (!name)
+		return IOEX_COUNT;
+
+	for (i = 0; i < IOEX_COUNT; i++) {
+		if (!strcasecmp(name, ioex_get_name(i)))
+			return i;
+	}
+
+	return IOEX_COUNT;
+}
+
+static enum ec_error_list ioex_set(const char *name, int value)
+{
+	enum ioex_signal signal = find_ioex_by_name(name);
+
+	if (signal == IOEX_COUNT)
+		return EC_ERROR_INVAL;
+
+	if (!(ioex_get_default_flags(signal) & GPIO_OUTPUT))
+		return EC_ERROR_INVAL;
+
+	return ioex_set_level(signal, value);
+}
+
+static int command_ioex_set(int argc, char **argv)
+{
+	char *e;
+	int v;
+
+	if (argc < 3)
+		return EC_ERROR_PARAM_COUNT;
+
+	v = strtoi(argv[2], &e, 0);
+	if (*e)
+		return EC_ERROR_PARAM2;
+
+	if (ioex_set(argv[1], v) != EC_SUCCESS)
+		return EC_ERROR_PARAM1;
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(ioexset, command_ioex_set,
+			"name <0 | 1>",
+			"Set level of a IO expander IO");
+
+static int command_ioex_get(int argc, char **argv)
+{
+	int i;
+
+	/* If a signal is specified, print only that one */
+	if (argc == 2) {
+		i = find_ioex_by_name(argv[1]);
+		if (i == IOEX_COUNT)
+			return EC_ERROR_PARAM1;
+		print_ioex_info(i);
+
+		return EC_SUCCESS;
+	}
+
+	/* Otherwise print them all */
+	for (i = 0; i < IOEX_COUNT; i++)
+		print_ioex_info(i);
+
+	return EC_SUCCESS;
+}
+DECLARE_SAFE_CONSOLE_COMMAND(ioexget, command_ioex_get,
+			     "[name]",
+			     "Read level of IO expander pin(s)");
+