driver: Add LN9310 switchcap driver

Add LN9310 2:1 and 3:1 switchcap driver. It will be used in Trogdor
projects.

BRANCH=None
BUG=b:163867792
TEST=Defined the CONFIG and built correctly.

Change-Id: I14b55c7cd3be06e3811cc58a182b1694e6ad57ff
Signed-off-by: Wai-Hong Tam <waihong@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2386481
Reviewed-by: Stephen Boyd <swboyd@chromium.org>

4 files changed, 325 insertions, 0 deletions

diff --git a/driver/build.mk b/driver/build.mk
index d970bd142b..5645c16094 100644
--- a/driver/build.mk
+++ b/driver/build.mk
@@ -180,6 +180,9 @@ endif
 driver-$(CONFIG_USBC_PPC_SYV682X)+=ppc/syv682x.o
 driver-$(CONFIG_USBC_PPC_NX20P3483)+=ppc/nx20p348x.o
 
+# Switchcap
+driver-$(CONFIG_LN9310)+=ln9310.o
+
 # video converters
 driver-$(CONFIG_MCDP28X0)+=mcdp28x0.o
 
diff --git a/driver/ln9310.c b/driver/ln9310.c
new file mode 100644
index 0000000000..5a82f3fa28
--- /dev/null
+++ b/driver/ln9310.c
@@ -0,0 +1,187 @@
+/* Copyright 2020 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.
+ *
+ * LION Semiconductor LN-9310 switched capacitor converter.
+ */
+
+#include "common.h"
+#include "console.h"
+#include "ln9310.h"
+#include "hooks.h"
+#include "i2c.h"
+#include "util.h"
+
+#define CPUTS(outstr) cputs(CC_CHIPSET, outstr)
+#define CPRINTF(format, args...) cprintf(CC_CHIPSET, format, ## args)
+#define CPRINTS(format, args...) cprints(CC_CHIPSET, format, ## args)
+
+static int power_good;
+
+int ln9310_power_good(void)
+{
+	return power_good;
+}
+
+static inline int raw_read8(int offset, int *value)
+{
+	return i2c_read8(ln9310_config.i2c_port,
+			 ln9310_config.i2c_addr_flags,
+			 offset,
+			 value);
+}
+
+static inline int field_update8(int offset, int mask, int value)
+{
+	/* Clear mask and then set value in i2c reg value */
+	return i2c_field_update8(ln9310_config.i2c_port,
+				 ln9310_config.i2c_addr_flags,
+				 offset,
+				 mask,
+				 value);
+}
+
+static void ln9310_irq_deferred(void)
+{
+	int status, val, pg_2to1, pg_3to1;
+
+	status = raw_read8(LN9310_REG_INT1, &val);
+	if (status) {
+		CPRINTS("LN9310 reading INT1 failed");
+		return;
+	}
+
+	CPRINTS("LN9310 received interrupt: 0x%x", val);
+	/* Don't care other interrupts except mode change */
+	if (!(val & LN9310_INT1_MODE))
+		return;
+
+	/* Check if the device is active in 2:1 or 3:1 switching mode */
+	status = raw_read8(LN9310_REG_SYS_STS, &val);
+	if (status) {
+		CPRINTS("LN9310 reading SYS_STS failed");
+		return;
+	}
+	CPRINTS("LN9310 system status: 0x%x", val);
+
+	/* Either 2:1 or 3:1 mode active is treated as PGOOD */
+	pg_2to1 = !!(val & LN9310_SYS_SWITCHING21_ACTIVE);
+	pg_3to1 = !!(val & LN9310_SYS_SWITCHING31_ACTIVE);
+	power_good = pg_2to1 || pg_3to1;
+}
+DECLARE_DEFERRED(ln9310_irq_deferred);
+
+void ln9310_interrupt(enum gpio_signal signal)
+{
+	hook_call_deferred(&ln9310_irq_deferred_data, 0);
+}
+
+static int is_battery_3s(void)
+{
+	int status, val, batt3s;
+
+	CPRINTS("LN9310 checking input voltage (2S/3S), threshold=10V");
+	/*
+	 * Turn on INFET_OUT_SWITCH_OK comparator;
+	 * configure INFET_OUT_SWITCH_OK to 10V.
+	 */
+	field_update8(LN9310_REG_TRACK_CTRL,
+		      LN9310_TRACK_INFET_OUT_SWITCH_OK_EN_MASK |
+				LN9310_TRACK_INFET_OUT_SWITCH_OK_CFG_MASK,
+		      LN9310_TRACK_INFET_OUT_SWITCH_OK_EN_ON |
+				LN9310_TRACK_INFET_OUT_SWITCH_OK_CFG_10V);
+
+	/* Read INFET_OUT_SWITCH_OK comparator */
+	status = raw_read8(LN9310_REG_BC_STS_B, &val);
+	if (status) {
+		CPRINTS("LN9310 reading BC_STS_B failed");
+		return -1;
+	}
+	CPRINTS("LN9310 BC_STS_B: 0x%x", val);
+
+	/*
+	 * If INFET_OUT_SWITCH_OK=0, VIN < 10V --> 2S battery
+	 * If INFET_OUT_SWITCH_OK=1, VIN > 10V --> 3S battery
+	 */
+	batt3s = !!(val & LN9310_BC_STS_B_INFET_OUT_SWITCH_OK);
+	CPRINTS("LN9310 %s battery detected", batt3s ? "3S" : "2S");
+
+	/* Turn off INFET_OUT_SWITCH_OK comparator */
+	field_update8(LN9310_REG_TRACK_CTRL,
+		      LN9310_TRACK_INFET_OUT_SWITCH_OK_EN_MASK,
+		      LN9310_TRACK_INFET_OUT_SWITCH_OK_EN_OFF);
+
+	return batt3s;
+}
+
+static void ln9310_init_3to1(void)
+{
+	CPRINTS("LN9310 init (3:1 operation)");
+
+	/* Enable track protection and SC_OUT configs for 3:1 switching */
+	field_update8(LN9310_REG_MODE_CHANGE_CFG,
+		      LN9310_MODE_TM_TRACK_MASK |
+				LN9310_MODE_TM_SC_OUT_PRECHG_MASK |
+				LN9310_MODE_TM_VIN_OV_CFG_MASK,
+		      LN9310_MODE_TM_TRACK_SWITCH31 |
+				LN9310_MODE_TM_SC_OUT_PRECHG_SWITCH31 |
+				LN9310_MODE_TM_VIN_OV_CFG_3S);
+
+	/* Enable 3:1 operation mode */
+	field_update8(LN9310_REG_PWR_CTRL,
+		      LN9310_PWR_OP_MODE_MASK,
+		      LN9310_PWR_OP_MODE_SWITCH31);
+
+	/* 3S lower bounde delta configurations */
+	field_update8(LN9310_REG_SYS_CTRL,
+		      LN9310_SYS_CTRL_LB_DELTA_MASK,
+		      LN9310_SYS_CTRL_LB_DELTA_3S);
+}
+
+static void ln9310_init_2to1(void)
+{
+	CPRINTS("LN9310 init (2:1 operation)");
+
+	/* Enable track protection and SC_OUT configs for 2:1 switching */
+	field_update8(LN9310_REG_MODE_CHANGE_CFG,
+		      LN9310_MODE_TM_TRACK_MASK |
+				LN9310_MODE_TM_SC_OUT_PRECHG_MASK,
+		      LN9310_MODE_TM_TRACK_SWITCH21 |
+				LN9310_MODE_TM_SC_OUT_PRECHG_SWITCH21);
+
+	/* Enable 2:1 operation mode */
+	field_update8(LN9310_REG_PWR_CTRL,
+		      LN9310_PWR_OP_MODE_MASK,
+		      LN9310_PWR_OP_MODE_SWITCH21);
+
+	/* 2S lower bounde delta configurations */
+	field_update8(LN9310_REG_SYS_CTRL,
+		      LN9310_SYS_CTRL_LB_DELTA_MASK,
+		      LN9310_SYS_CTRL_LB_DELTA_2S);
+}
+
+void ln9310_init(void)
+{
+	int status, val, batt3s;
+
+	batt3s = is_battery_3s();
+	if (batt3s == -1)
+		return;
+	else if (batt3s)
+		ln9310_init_3to1();
+	else
+		ln9310_init_2to1();
+
+	/* Unmask the MODE change interrupt */
+	field_update8(LN9310_REG_INT1_MSK,
+		      LN9310_INT1_MODE,
+		      0);
+
+	/* Dummy clear all interrupts */
+	status = raw_read8(LN9310_REG_INT1, &val);
+	if (status) {
+		CPRINTS("LN9310 reading INT1 failed");
+		return;
+	}
+	CPRINTS("LN9310 cleared interrupts: 0x%x", val);
+}
diff --git a/driver/ln9310.h b/driver/ln9310.h
new file mode 100644
index 0000000000..92aa16e822
--- /dev/null
+++ b/driver/ln9310.h
@@ -0,0 +1,133 @@
+/* Copyright 2020 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.
+ *
+ * LION Semiconductor LN-9310 switched capacitor converter.
+ */
+
+#ifndef __CROS_EC_LN9310_H
+#define __CROS_EC_LN9310_H
+
+/* I2C address */
+#define LN9310_I2C_ADDR_0_FLAGS		0x72
+#define LN9310_I2C_ADDR_1_FLAGS		0x73
+#define LN9310_I2C_ADDR_2_FLAGS		0x53
+#define LN9310_I2C_ADDR_3_FLAGS		0x54
+
+/* Registers */
+#define LN9310_REG_CHIP_ID		0x00
+#define LN9310_CHIP_ID			0x44
+#define LN9310_REG_INT1			0x01
+#define LN9310_REG_INT1_MSK		0x02
+#define LN9310_INT1_TIMER		BIT(0)
+#define LN9310_INT1_INFET		BIT(1)
+#define LN9310_INT1_TEMP		BIT(2)
+#define LN9310_INT1_REV_CURR		BIT(3)
+#define LN9310_INT1_MODE		BIT(4)
+#define LN9310_INT1_ALARM		BIT(5)
+#define LN9310_INT1_OK			BIT(6)
+#define LN9310_INT1_FAULT		BIT(7)
+
+#define LN9310_REG_SYSGPIO_MSK		0x03
+
+#define LN9310_REG_SYS_STS		0x04
+#define LN9310_SYS_STANDBY		BIT(0)
+#define LN9310_SYS_SWITCHING21_ACTIVE	BIT(1)
+#define LN9310_SYS_SWITCHING31_ACTIVE	BIT(2)
+#define LN9310_SYS_BYPASS_ACTIVE	BIT(3)
+#define LN9310_SYS_INFET_OK		BIT(4)
+#define LN9310_SYS_SC_OUT_SWITCH_OK	BIT(5)
+#define LN9310_SYS_INFET_OUT_SWITCH_OK	BIT(6)
+
+#define LN9310_REG_SAFETY_STS		0x05
+#define LN9310_REG_FAULT1_STS		0x06
+#define LN9310_REG_FAULT2_STS		0x07
+
+#define LN9310_REG_PWR_CTRL		0x1d
+#define LN9310_PWR_OP_MODE0		BIT(0)
+#define LN9310_PWR_OP_MODE1		BIT(1)
+#define LN9310_PWR_INFET_EN		BIT(2)
+#define LN9310_PWR_INFET_AUTO_MODE	BIT(3)
+#define LN9310_PWR_REVERSE_MODE		BIT(4)
+#define LN9310_PWR_VIN_OV_IGNORE	BIT(5)
+#define LN9310_PWR_OP_MANUAL_UPDATE	BIT(6)
+#define LN9310_PWR_FORCE_INSNS_EN	BIT(7)
+#define LN9310_PWR_OP_MODE_MASK		0x03
+#define LN9310_PWR_OP_MODE_DISABLED	0x00
+#define LN9310_PWR_OP_MODE_BYPASS	0x01
+#define LN9310_PWR_OP_MODE_SWITCH21	0x02
+#define LN9310_PWR_OP_MODE_SWITCH31	0x03
+
+#define LN9310_REG_SYS_CTRL		0x1e
+#define LN9310_SYS_CTRL_LB_DELTA_MASK	0x38
+#define LN9310_SYS_CTRL_LB_DELTA_2S	0x4
+#define LN9310_SYS_CTRL_LB_DELTA_3S	0x4
+
+#define LN9310_REG_STARTUP_CTRL		0x1f
+#define LN9310_REG_IIN_CTRL		0x20
+#define LN9310_REG_VIN_CTRL		0x21
+
+#define LN9310_REG_TRACK_CTRL		0x22
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_EN		BIT(7)
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_CFG2		BIT(6)
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_CFG1		BIT(5)
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_CFG0		BIT(4)
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_EN_MASK	0x80
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_EN_ON		0x80
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_EN_OFF		0x00
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_CFG_MASK	0x70
+#define LN9310_TRACK_INFET_OUT_SWITCH_OK_CFG_10V	0x10
+
+#define LN9310_REG_OCP_CTRL		0x23
+#define LN9310_REG_TIMER_CTRL		0x24
+#define LN9310_REG_RECOVERY_CTRL	0x25
+#define LN9310_REG_LB_CTRL		0x26
+#define LN9310_REG_SC_OUT_OV_CTRL	0x29
+#define LN9310_REG_STS_CTRL		0x2d
+
+#define LN9310_REG_MODE_CHANGE_CFG	0x2e
+#define LN9310_MODE_TM_VIN_OV_CFG0		BIT(0)
+#define LN9310_MODE_TM_VIN_OV_CFG1		BIT(1)
+#define LN9310_MODE_TM_VIN_OV_CFG2		BIT(2)
+#define LN9310_MODE_TM_SC_OUT_PRECHG_CFG0	BIT(3)
+#define LN9310_MODE_TM_SC_OUT_PRECHG_CFG1	BIT(4)
+#define LN9310_MODE_TM_TRACK_CFG0		BIT(5)
+#define LN9310_MODE_TM_TRACK_CFG1		BIT(6)
+#define LN9310_MODE_FORCE_MODE_CFG		BIT(7)
+#define LN9310_MODE_TM_TRACK_MASK		0x60
+#define LN9310_MODE_TM_TRACK_BYPASS		0x00
+#define LN9310_MODE_TM_TRACK_SWITCH21		0x20
+#define LN9310_MODE_TM_TRACK_SWITCH31		0x60
+#define LN9310_MODE_TM_SC_OUT_PRECHG_MASK	0x18
+#define LN9310_MODE_TM_SC_OUT_PRECHG_BYPASS	0x0
+#define LN9310_MODE_TM_SC_OUT_PRECHG_SWITCH21	0x08
+#define LN9310_MODE_TM_SC_OUT_PRECHG_SWITCH31	0x18
+#define LN9310_MODE_TM_VIN_OV_CFG_MASK		0x07
+#define LN9310_MODE_TM_VIN_OV_CFG_2S		0x0  /* 14V */
+#define LN9310_MODE_TM_VIN_OV_CFG_3S		0x2  /* 20V */
+
+#define LN9310_REG_SC_DITHER_CTRL	0x2f
+
+#define LN9310_REG_BC_STS_B		0x51
+#define LN9310_BC_STS_B_INFET_OUT_SWITCH_OK		BIT(5)
+#define LN9310_BC_STS_B_INFET_OUT_SWITCH_OK_MASK	0x20
+
+/* Define configuration of LN9310 part */
+struct ln9310_config_t {
+	const int i2c_port;
+	const int i2c_addr_flags;
+};
+
+/* Configuration struct defined at board level */
+extern const struct ln9310_config_t ln9310_config;
+
+/* Init the driver */
+void ln9310_init(void);
+
+/* Interrupt handler */
+void ln9310_interrupt(enum gpio_signal signal);
+
+/* Return the POWER_GOOD status */
+int ln9310_power_good(void);
+
+#endif /* __CROS_EC_LN9310_H */
diff --git a/include/config.h b/include/config.h
index ea17b81bb7..50b0a12e75 100644
--- a/include/config.h
+++ b/include/config.h
@@ -3739,6 +3739,8 @@
 #undef CONFIG_UART_TX_REQ_CH
 #undef CONFIG_UART_RX_REQ_CH
 
+/* Driver of LN9310 switchcap */
+#undef CONFIG_LN9310
 
 /*****************************************************************************/
 /* USB PD config */