platform: sifive_fu740: add platform reset driver

da9063 PMIC can be used to reset/shutdown the
Sifive Unmatched board.

shutdown is done simply by writing SHUTDOWN bit to
DA9063_REG_CONTROL_F register.

reset via setting WAKEUP bit in DA9063_REG_CONTROL_F
register followed by masking POWER and POWER1 domains
and setting STANDBY bit in DA9063_REG_CONTROL_A,
originally discovered by Alexandre Ghiti on linux-riscv
maillists.

Tested-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Tested-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Nikita Shubin <n.shubin@yadro.com>

1 files changed, 194 insertions, 0 deletions

diff --git a/platform/generic/sifive_fu740.c b/platform/generic/sifive_fu740.c
index c8325d3..3152152 100644
--- a/platform/generic/sifive_fu740.c
+++ b/platform/generic/sifive_fu740.c
@@ -2,14 +2,191 @@
  * SPDX-License-Identifier: BSD-2-Clause
  *
  * Copyright (c) 2021 SiFive
+ * Copyright (c) 2021 YADRO
  *
  * Authors:
  *   David Abdurachmanov <david.abdurachmanov@sifive.com>
+ *   Nikita Shubin <n.shubin@yadro.com>
  */
 
 #include <platform_override.h>
+#include <libfdt.h>
+#include <sbi/sbi_error.h>
+#include <sbi/sbi_system.h>
+#include <sbi/sbi_console.h>
 #include <sbi_utils/fdt/fdt_helper.h>
 #include <sbi_utils/fdt/fdt_fixup.h>
+#include <sbi_utils/reset/fdt_reset.h>
+#include <sbi_utils/i2c/fdt_i2c.h>
+
+#define DA9063_REG_PAGE_CON		0x00
+#define DA9063_REG_CONTROL_A		0x0e
+#define DA9063_REG_CONTROL_F		0x13
+#define DA9063_REG_DEVICE_ID		0x81
+
+#define DA9063_CONTROL_A_M_POWER1_EN	(1 << 6)
+#define DA9063_CONTROL_A_M_POWER_EN	(1 << 5)
+#define DA9063_CONTROL_A_STANDBY	(1 << 3)
+
+#define DA9063_CONTROL_F_WAKEUP	(1 << 2)
+#define DA9063_CONTROL_F_SHUTDOWN	(1 << 1)
+
+#define PMIC_CHIP_ID_DA9063		0x61
+
+static struct {
+	struct i2c_adapter *adapter;
+	uint32_t reg;
+} da9063;
+
+static int da9063_system_reset_check(u32 type, u32 reason)
+{
+	switch (type) {
+	case SBI_SRST_RESET_TYPE_SHUTDOWN:
+		return 1;
+	case SBI_SRST_RESET_TYPE_COLD_REBOOT:
+	case SBI_SRST_RESET_TYPE_WARM_REBOOT:
+		return 255;
+	}
+
+	return 0;
+}
+
+static inline int da9063_sanity_check(struct i2c_adapter *adap, uint32_t reg)
+{
+	uint8_t val;
+	int rc = i2c_adapter_reg_write(adap, reg, DA9063_REG_PAGE_CON, 0x02);
+
+	if (rc)
+		return rc;
+
+	/* check set page*/
+	rc = i2c_adapter_reg_read(adap, reg, 0x0, &val);
+	if (rc)
+		return rc;
+
+	if (val != 0x02)
+		return SBI_ENODEV;
+
+	/* read and check device id */
+	rc = i2c_adapter_reg_read(adap, reg, DA9063_REG_DEVICE_ID, &val);
+	if (rc)
+		return rc;
+
+	if (val != PMIC_CHIP_ID_DA9063)
+		return SBI_ENODEV;
+
+	return 0;
+}
+
+static inline int da9063_shutdown(struct i2c_adapter *adap, uint32_t reg)
+{
+	int rc = i2c_adapter_reg_write(adap, da9063.reg,
+					DA9063_REG_PAGE_CON, 0x00);
+
+	if (rc)
+		return rc;
+
+	return i2c_adapter_reg_write(adap, da9063.reg,
+				     DA9063_REG_CONTROL_F,
+				     DA9063_CONTROL_F_SHUTDOWN);
+}
+
+static inline int da9063_reset(struct i2c_adapter *adap, uint32_t reg)
+{
+	int rc = i2c_adapter_reg_write(adap, da9063.reg,
+					DA9063_REG_PAGE_CON, 0x00);
+
+	if (rc)
+		return rc;
+
+	rc = i2c_adapter_reg_write(adap, da9063.reg,
+				   DA9063_REG_CONTROL_F,
+				   DA9063_CONTROL_F_WAKEUP);
+	if (rc)
+		return rc;
+
+	return i2c_adapter_reg_write(adap, da9063.reg,
+				DA9063_REG_CONTROL_A,
+				DA9063_CONTROL_A_M_POWER1_EN |
+				DA9063_CONTROL_A_M_POWER_EN |
+				DA9063_CONTROL_A_STANDBY);
+}
+
+static void da9063_system_reset(u32 type, u32 reason)
+{
+	struct i2c_adapter *adap = da9063.adapter;
+	uint32_t reg = da9063.reg;
+	int rc;
+
+	if (adap) {
+		/* sanity check */
+		rc = da9063_sanity_check(adap, reg);
+		if (rc) {
+			sbi_printf("%s: chip is not da9063 PMIC\n", __func__);
+			goto skip_reset;
+		}
+
+		switch (type) {
+		case SBI_SRST_RESET_TYPE_SHUTDOWN:
+			da9063_shutdown(adap, reg);
+			break;
+		case SBI_SRST_RESET_TYPE_COLD_REBOOT:
+		case SBI_SRST_RESET_TYPE_WARM_REBOOT:
+			da9063_reset(adap, reg);
+			break;
+		}
+	}
+
+skip_reset:
+	sbi_hart_hang();
+}
+
+static struct sbi_system_reset_device da9063_reset_i2c = {
+	.name = "da9063-reset",
+	.system_reset_check = da9063_system_reset_check,
+	.system_reset = da9063_system_reset
+};
+
+static int da9063_reset_init(void *fdt, int nodeoff,
+			     const struct fdt_match *match)
+{
+	int rc, i2c_bus;
+	struct i2c_adapter *adapter;
+	uint64_t addr;
+
+	/* we are dlg,da9063 node */
+	rc = fdt_get_node_addr_size(fdt, nodeoff, 0, &addr, NULL);
+	if (rc)
+		return rc;
+
+	da9063.reg = addr;
+
+	/* find i2c bus parent node */
+	i2c_bus = fdt_parent_offset(fdt, nodeoff);
+	if (i2c_bus < 0)
+		return i2c_bus;
+
+	/* i2c adapter get */
+	rc = fdt_i2c_adapter_get(fdt, i2c_bus, &adapter);
+	if (rc)
+		return rc;
+
+	da9063.adapter = adapter;
+
+	sbi_system_reset_add_device(&da9063_reset_i2c);
+
+	return 0;
+}
+
+static const struct fdt_match da9063_reset_match[] = {
+	{ .compatible = "dlg,da9063", .data = (void *)TRUE },
+	{ },
+};
+
+struct fdt_reset fdt_reset_da9063 = {
+	.match_table = da9063_reset_match,
+	.init = da9063_reset_init,
+};
 
 static u64 sifive_fu740_tlbr_flush_limit(const struct fdt_match *match)
 {
@@ -23,6 +200,22 @@ static u64 sifive_fu740_tlbr_flush_limit(const struct fdt_match *match)
 	return 0;
 }
 
+static int sifive_fu740_final_init(bool cold_boot,
+				   const struct fdt_match *match)
+{
+	int rc;
+	void *fdt = fdt_get_address();
+
+	if (cold_boot) {
+		rc = fdt_reset_driver_init(fdt, &fdt_reset_da9063);
+		if (rc)
+			sbi_printf("%s: failed to find da9063 for reset\n",
+				   __func__);
+	}
+
+	return 0;
+}
+
 static const struct fdt_match sifive_fu740_match[] = {
 	{ .compatible = "sifive,fu740" },
 	{ .compatible = "sifive,fu740-c000" },
@@ -33,4 +226,5 @@ static const struct fdt_match sifive_fu740_match[] = {
 const struct platform_override sifive_fu740 = {
 	.match_table = sifive_fu740_match,
 	.tlbr_flush_limit = sifive_fu740_tlbr_flush_limit,
+	.final_init = sifive_fu740_final_init,
 };