Add a pass-through for TPSchrome LDOs

Allow to send commands to switch on/off the TPSchrome LDOs by using EC commands
when the TPSchrome chip is connected to an I2C bus behind the EC.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=chrome-os-partner:14314
TEST=on Spring, with an updated bootloader, switch on screen FETs from
U-Boot instead of hardcoding them in the EC board code.

Change-Id: Ic6cebf04ba73a7c0ca2c54f532f8cf4c953ac0c1
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/41288
Reviewed-by: Vic Yang <victoryang@chromium.org>

2 files changed, 77 insertions, 0 deletions

diff --git a/common/pmu_tps65090.c b/common/pmu_tps65090.c
index e6e67a1ead..7a587e1b21 100644
--- a/common/pmu_tps65090.c
+++ b/common/pmu_tps65090.c
@@ -8,6 +8,7 @@
 #include "clock.h"
 #include "console.h"
 #include "common.h"
+#include "host_command.h"
 #include "hooks.h"
 #include "i2c.h"
 #include "pmu_tpschrome.h"
@@ -601,3 +602,48 @@ DECLARE_CONSOLE_COMMAND(pmu, command_pmu,
 			"Print PMU info or force a hard reset",
 			NULL);
 #endif
+
+/*****************************************************************************/
+/* TPSchrome LDO pass-through
+ */
+#ifdef CONFIG_I2C_PASSTHROUGH
+static int host_command_ldo_get(struct host_cmd_handler_args *args)
+{
+	int rv;
+	int val;
+	const struct ec_params_ldo_get *p = args->params;
+	struct ec_response_ldo_get *r = args->response;
+
+	/* is this an existing TPSchrome FET ? */
+	if ((p->index < 1) || (p->index > 7))
+		return EC_RES_ERROR;
+
+	rv = pmu_read(FET_CTRL_BASE + p->index, &val);
+	if (rv)
+		return EC_RES_ERROR;
+
+	r->state = !!(val & FET_CTRL_PGFET);
+	args->response_size = sizeof(struct ec_response_ldo_get);
+
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_LDO_GET,
+		     host_command_ldo_get,
+		     EC_VER_MASK(0));
+
+static int host_command_ldo_set(struct host_cmd_handler_args *args)
+{
+	int rv;
+	const struct ec_params_ldo_set *p = args->params;
+
+	/* is this an existing TPSchrome FET ? */
+	if ((p->index < 1) || (p->index > 7))
+		return EC_RES_ERROR;
+	rv = pmu_enable_fet(p->index, p->state & EC_LDO_STATE_ON, NULL);
+
+	return rv ? EC_RES_ERROR : EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_LDO_SET,
+		     host_command_ldo_set,
+		     EC_VER_MASK(0));
+#endif
diff --git a/include/ec_commands.h b/include/ec_commands.h
index 9459800693..02fa46f1bf 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -1211,6 +1211,37 @@ struct ec_params_usb_mux {
 } __packed;
 
 /*****************************************************************************/
+/* LDOs / FETs control. */
+
+enum ec_ldo_state {
+	EC_LDO_STATE_OFF = 0,	/* the LDO / FET is shut down */
+	EC_LDO_STATE_ON = 1,	/* the LDO / FET is ON / providing power */
+};
+
+/*
+ * Switch on/off a LDO.
+ */
+#define EC_CMD_LDO_SET 0x9b
+
+struct ec_params_ldo_set {
+	uint8_t index;
+	uint8_t state;
+} __packed;
+
+/*
+ * Get LDO state.
+ */
+#define EC_CMD_LDO_GET 0x9c
+
+struct ec_params_ldo_get {
+	uint8_t index;
+} __packed;
+
+struct ec_response_ldo_get {
+	uint8_t state;
+} __packed;
+
+/*****************************************************************************/
 /* Temporary debug commands. TODO: remove this crosbug.com/p/13849 */
 
 /*