cros_ec: power: Add a tunnelled version of the tps65090 driver

Unfortunately on Pit the AP has no direct access to the tps65090 but must
talk through the EC (over SPI) to the EC's I2C bus.

When driver model supports PMICs this will be relatively easy. In the
meantime the best approach is to duplicate the driver. It will be refactored
once driver model support is expanded.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Ajay Kumar <ajaykumar.rs@samsung.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>

drivers/power/pmic/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_POWER_MUIC_MAX8997) += muic_max8997.o
 obj-$(CONFIG_POWER_MAX77686) += pmic_max77686.o
 obj-$(CONFIG_POWER_PFUZE100) += pmic_pfuze100.o
 obj-$(CONFIG_POWER_TPS65090) += pmic_tps65090.o
+obj-$(CONFIG_POWER_TPS65090_EC) += pmic_tps65090_ec.o
 obj-$(CONFIG_POWER_TPS65217) += pmic_tps65217.o
 obj-$(CONFIG_POWER_TPS65218) += pmic_tps65218.o
 obj-$(CONFIG_POWER_TPS65910) += pmic_tps65910.o

drivers/power/pmic/pmic_tps65090_ec.c

@@ -0,0 +1,218 @@
+/*
+ * Copyright (c) 2013 The Chromium OS Authors.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <cros_ec.h>
+#include <errno.h>
+#include <power/tps65090_pmic.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define TPS65090_ADDR		0x48
+
+static struct tps65090 {
+	struct cros_ec_dev *dev;		/* The CROS_EC device */
+} config;
+
+/* TPS65090 register addresses */
+enum {
+	REG_IRQ1 = 0,
+	REG_CG_CTRL0 = 4,
+	REG_CG_STATUS1 = 0xa,
+	REG_FET1_CTRL = 0x0f,
+	REG_FET2_CTRL,
+	REG_FET3_CTRL,
+	REG_FET4_CTRL,
+	REG_FET5_CTRL,
+	REG_FET6_CTRL,
+	REG_FET7_CTRL,
+	TPS65090_NUM_REGS,
+};
+
+enum {
+	IRQ1_VBATG = 1 << 3,
+	CG_CTRL0_ENC_MASK	= 0x01,
+
+	MAX_FET_NUM	= 7,
+	MAX_CTRL_READ_TRIES = 5,
+
+	/* TPS65090 FET_CTRL register values */
+	FET_CTRL_TOFET		= 1 << 7,  /* Timeout, startup, overload */
+	FET_CTRL_PGFET		= 1 << 4,  /* Power good for FET status */
+	FET_CTRL_WAIT		= 3 << 2,  /* Overcurrent timeout max */
+	FET_CTRL_ADENFET	= 1 << 1,  /* Enable output auto discharge */
+	FET_CTRL_ENFET		= 1 << 0,  /* Enable FET */
+};
+
+/**
+ * tps65090_read - read a byte from tps6090
+ *
+ * @param reg		The register address to read from.
+ * @param val		We'll return value value read here.
+ * @return 0 if ok; error if EC returns failure.
+ */
+static int tps65090_read(u32 reg, u8 *val)
+{
+	return cros_ec_i2c_xfer(config.dev, TPS65090_ADDR, reg, 1,
+				val, 1, true);
+}
+
+/**
+ * tps65090_write - write a byte to tps6090
+ *
+ * @param reg		The register address to write to.
+ * @param val		The value to write.
+ * @return 0 if ok; error if EC returns failure.
+ */
+static int tps65090_write(u32 reg, u8 val)
+{
+	return cros_ec_i2c_xfer(config.dev, TPS65090_ADDR, reg, 1,
+				&val, 1, false);
+}
+
+/**
+ * Checks for a valid FET number
+ *
+ * @param fet_id	FET number to check
+ * @return 0 if ok, -EINVAL if FET value is out of range
+ */
+static int tps65090_check_fet(unsigned int fet_id)
+{
+	if (fet_id == 0 || fet_id > MAX_FET_NUM) {
+		debug("parameter fet_id is out of range, %u not in 1 ~ %u\n",
+		      fet_id, MAX_FET_NUM);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * Set the power state for a FET
+ *
+ * @param fet_id	Fet number to set (1..MAX_FET_NUM)
+ * @param set		1 to power on FET, 0 to power off
+ * @return -EIO if we got a comms error, -EAGAIN if the FET failed to
+ * change state. If all is ok, returns 0.
+ */
+static int tps65090_fet_set(int fet_id, bool set)
+{
+	int retry;
+	u8 reg, value;
+
+	value = FET_CTRL_ADENFET | FET_CTRL_WAIT;
+	if (set)
+		value |= FET_CTRL_ENFET;
+
+	if (tps65090_write(REG_FET1_CTRL + fet_id - 1, value))
+		return -EIO;
+
+	/* Try reading until we get a result */
+	for (retry = 0; retry < MAX_CTRL_READ_TRIES; retry++) {
+		if (tps65090_read(REG_FET1_CTRL + fet_id - 1, &reg))
+			return -EIO;
+
+		/* Check that the fet went into the expected state */
+		if (!!(reg & FET_CTRL_PGFET) == set)
+			return 0;
+
+		/* If we got a timeout, there is no point in waiting longer */
+		if (reg & FET_CTRL_TOFET)
+			break;
+
+		mdelay(1);
+	}
+
+	debug("FET %d: Power good should have set to %d but reg=%#02x\n",
+	      fet_id, set, reg);
+	return -EAGAIN;
+}
+
+int tps65090_fet_enable(unsigned int fet_id)
+{
+	ulong start;
+	int loops;
+	int ret;
+
+	ret = tps65090_check_fet(fet_id);
+	if (ret)
+		return ret;
+
+	start = get_timer(0);
+	for (loops = 0;; loops++) {
+		ret = tps65090_fet_set(fet_id, true);
+		if (!ret)
+			break;
+
+		if (get_timer(start) > 100)
+			break;
+
+		/* Turn it off and try again until we time out */
+		tps65090_fet_set(fet_id, false);
+	}
+
+	if (ret) {
+		debug("%s: FET%d failed to power on: time=%lums, loops=%d\n",
+		      __func__, fet_id, get_timer(start), loops);
+	} else if (loops) {
+		debug("%s: FET%d powered on after %lums, loops=%d\n",
+		      __func__, fet_id, get_timer(start), loops);
+	}
+	/*
+	 * Unfortunately, there are some conditions where the power
+	 * good bit will be 0, but the fet still comes up. One such
+	 * case occurs with the lcd backlight. We'll just return 0 here
+	 * and assume that the fet will eventually come up.
+	 */
+	if (ret == -EAGAIN)
+		ret = 0;
+
+	return ret;
+}
+
+int tps65090_fet_disable(unsigned int fet_id)
+{
+	int ret;
+
+	ret = tps65090_check_fet(fet_id);
+	if (ret)
+		return ret;
+
+	ret = tps65090_fet_set(fet_id, false);
+
+	return ret;
+}
+
+int tps65090_fet_is_enabled(unsigned int fet_id)
+{
+	u8 reg = 0;
+	int ret;
+
+	ret = tps65090_check_fet(fet_id);
+	if (ret)
+		return ret;
+	ret = tps65090_read(REG_FET1_CTRL + fet_id - 1, &reg);
+	if (ret) {
+		debug("fail to read FET%u_CTRL register over I2C", fet_id);
+		return -EIO;
+	}
+
+	return reg & FET_CTRL_ENFET;
+}
+
+int tps65090_init(void)
+{
+	puts("TPS65090 PMIC EC init\n");
+
+	config.dev = board_get_cros_ec_dev();
+	if (!config.dev) {
+		debug("%s: no cros_ec device: cannot init tps65090\n",
+		      __func__);
+		return -ENODEV;
+	}
+
+	return 0;
+}