misc: pmic_esm: Add support for PMIC ESM driver

The ESM (Error Signal Monitor) is used on certain PMIC versions to
handle error signals propagating from rest of the system. If these
reach the PMIC, it is typically a last resort fatal error which
requires a system reset. The ESM driver does the proper configuration
for the ESM module to reach this end goal. Initially, only TPS65941
PMIC is supported for this.

Signed-off-by: Tero Kristo <t-kristo@ti.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/drivers/misc/esm_pmic.c b/drivers/misc/esm_pmic.c
new file mode 100644
index 0000000000..92c8d68f7c
--- /dev/null
+++ b/drivers/misc/esm_pmic.c
@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PMIC Error Signal Monitor driver
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+ *      Tero Kristo <t-kristo@ti.com>
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <power/pmic.h>
+#include <dm/device_compat.h>
+
+#define INT_ESM_REG		0x6c
+#define INT_ESM_MASK		0x3f
+
+#define ESM_MCU_START_REG	0x8f
+
+#define ESM_MCU_START		BIT(0)
+
+#define ESM_MCU_MODE_CFG_REG	0x92
+
+#define ESM_MCU_EN		BIT(6)
+#define ESM_MCU_ENDRV		BIT(5)
+
+/**
+ * pmic_esm_probe: configures and enables PMIC ESM functionality
+ *
+ * Configures ESM PMIC support and enables it.
+ */
+static int pmic_esm_probe(struct udevice *dev)
+{
+	int ret;
+
+	ret = pmic_reg_write(dev->parent, INT_ESM_REG, INT_ESM_MASK);
+	if (ret) {
+		dev_err(dev, "clearing ESM irqs failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = pmic_reg_write(dev->parent, ESM_MCU_MODE_CFG_REG,
+			     ESM_MCU_EN | ESM_MCU_ENDRV);
+	if (ret) {
+		dev_err(dev, "setting ESM mode failed: %d\n", ret);
+		return ret;
+	}
+
+	ret = pmic_reg_write(dev->parent, ESM_MCU_START_REG, ESM_MCU_START);
+	if (ret) {
+		dev_err(dev, "starting ESM failed: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id pmic_esm_ids[] = {
+	{ .compatible = "ti,tps659413-esm" },
+	{}
+};
+
+U_BOOT_DRIVER(pmic_esm) = {
+	.name = "esm_pmic",
+	.of_match = pmic_esm_ids,
+	.id = UCLASS_MISC,
+	.probe = pmic_esm_probe,
+};