[PATCH v5 0/4] Support ROHM BD9576MUF and BD9573MUF PMICs

[PATCH v5 0/4] Support ROHM BD9576MUF and BD9573MUF PMICs

[Matti Vaittinen]

Initial support for ROHM BD9576MUF and BD9573MUF PMICs.

These PMICs are primarily intended to be used to power the R-Car family
processors. BD9576MUF includes some additional safety features the
BD9573MUF does not have. This initial version of drivers does not
utilize these features and for now the SW behaviour is identical.

This patch series includes MFD and watchdog drivers. Regulator part was
already applied.

- Enabling and pinging the watchdog
- configuring watchog timeout / window from device-tree

This patch series does not bring interrupt support. BD9576MUF and BD9573MUF
are designed to keep the IRQ line low for whole duration of error
condition. IRQ can't be 'acked'. So proper IRQ support would require
some IRQ limiter implementation (delayed unmask?) in order to not hog
the CPU.

Changelog v5:
  - rebased on top of v5.10-rc2
  - few styling fixes in MFD as suggested by Lee

Changelog v4:
  - rebased on top of 5.10-rc1
  - Fix typo (repeated word maximum) from the DT binding doc

Changelog v3:
  - use only one binding to specify watchdog time-out window.

Changelog v2:
  - dropped already applied regulator part
  - dt_bindings: Fix case for regulator-names in the example
  - watchdod: unify probe error check and revise includes

---

Matti Vaittinen (4):
  dt_bindings: mfd: Add ROHM BD9576MUF and BD9573MUF PMICs
  mfd: Support ROHM BD9576MUF and BD9573MUF
  wdt: Support wdt on ROHM BD9576MUF and BD9573MUF
  MAINTAINERS: Add ROHM BD9576MUF and BD9573MUF drivers

 .../bindings/mfd/rohm,bd9576-pmic.yaml        | 123 ++++++++
 MAINTAINERS                                   |   4 +
 drivers/mfd/Kconfig                           |  11 +
 drivers/mfd/Makefile                          |   1 +
 drivers/mfd/rohm-bd9576.c                     | 108 +++++++
 drivers/watchdog/Kconfig                      |  13 +
 drivers/watchdog/Makefile                     |   1 +
 drivers/watchdog/bd9576_wdt.c                 | 290 ++++++++++++++++++
 include/linux/mfd/rohm-bd957x.h               |  59 ++++
 include/linux/mfd/rohm-generic.h              |   2 +
 10 files changed, 612 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/rohm,bd9576-pmic.yaml
 create mode 100644 drivers/mfd/rohm-bd9576.c
 create mode 100644 drivers/watchdog/bd9576_wdt.c
 create mode 100644 include/linux/mfd/rohm-bd957x.h


base-commit: 3cea11cd5e3b00d91caf0b4730194039b45c5891
-- 
2.21.3


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =] 

[PATCH v5 1/4] dt_bindings: mfd: Add ROHM BD9576MUF and BD9573MUF PMICs

[Matti Vaittinen]

Add bindings for ROHM BD9576MUF and BD9573MUF PMICs. These
PMICs are primarily intended to be used to power the R-Car series
processors. They provide 6 power outputs, safety features and a
watchdog with two functional modes.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/mfd/rohm,bd9576-pmic.yaml        | 123 ++++++++++++++++++
 1 file changed, 123 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/rohm,bd9576-pmic.yaml

diff --git a/Documentation/devicetree/bindings/mfd/rohm,bd9576-pmic.yaml b/Documentation/devicetree/bindings/mfd/rohm,bd9576-pmic.yaml
new file mode 100644
index 000000000000..6483860da955
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/rohm,bd9576-pmic.yaml
@@ -0,0 +1,123 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mfd/rohm,bd9576-pmic.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ROHM BD9576MUF and BD9573MUF Power Management Integrated Circuit bindings
+
+maintainers:
+  - Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
+
+description: |
+  BD9576MUF and BD9573MUF are power management ICs primarily intended for
+  powering the R-Car series processors.
+  The IC provides 6 power outputs with configurable sequencing and safety
+  monitoring. A watchdog logic with slow ping/windowed modes is also included.
+
+properties:
+  compatible:
+    enum:
+      - rohm,bd9576
+      - rohm,bd9573
+
+  reg:
+    description:
+      I2C slave address.
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  rohm,vout1-en-low:
+    description:
+      BD9576 and BD9573 VOUT1 regulator enable state can be individually
+      controlled by a GPIO. This is dictated by state of vout1-en pin during
+      the PMIC startup. If vout1-en is LOW during PMIC startup then the VOUT1
+      enable sate is controlled via this pin. Set this property if vout1-en
+      is wired to be down at PMIC start-up.
+    type: boolean
+
+  rohm,vout1-en-gpios:
+    description:
+      GPIO specifier to specify the GPIO connected to vout1-en for vout1 ON/OFF
+      state control.
+    maxItems: 1
+
+  rohm,ddr-sel-low:
+    description:
+      The BD9576 and BD9573 output voltage for DDR can be selected by setting
+      the ddr-sel pin low or high. Set this property if ddr-sel is grounded.
+    type: boolean
+
+  rohm,watchdog-enable-gpios:
+    description: The GPIO line used to enable the watchdog.
+    maxItems: 1
+
+  rohm,watchdog-ping-gpios:
+    description: The GPIO line used to ping the watchdog.
+    maxItems: 1
+
+  rohm,hw-timeout-ms:
+    maxItems: 2
+    description:
+      Watchog timeout in milliseconds. If single value is given it is
+      the maximum timeout. Eg. if pinging watchdog is not done within this time
+      limit the watchdog will be triggered. If two values are given watchdog
+      is configured in "window mode". Then first value is limit for short-ping
+      Eg. if watchdog is pinged sooner than that the watchdog will trigger.
+      When two values is given the second value is the maximum timeout.
+      # (HW) minimum for short timeout is 2ms, maximum 220 ms.
+      # (HW) minimum for max timeout is 4ms, maximum 4416 ms.
+
+  regulators:
+    $ref: ../regulator/rohm,bd9576-regulator.yaml
+    description:
+      List of child nodes that specify the regulators.
+
+required:
+  - compatible
+  - reg
+  - regulators
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/leds/common.h>
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        pmic: pmic@30 {
+            compatible = "rohm,bd9576";
+            reg = <0x30>;
+            rohm,vout1-en-low;
+            rohm,vout1-en-gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>;
+            rohm,ddr-sel-low;
+            rohm,watchdog-enable-gpios = <&gpio2 6 GPIO_ACTIVE_HIGH>;
+            rohm,watchdog-ping-gpios = <&gpio2 7 GPIO_ACTIVE_HIGH>;
+            rohm,hw-timeout-ms = <150>, <2300>;
+
+            regulators {
+                boost1: regulator-vd50 {
+                    regulator-name = "VD50";
+                };
+                buck1: regulator-vd18 {
+                    regulator-name = "VD18";
+                };
+                buck2: regulator-vdddr {
+                    regulator-name = "VDDDR";
+                };
+                buck3: regulator-vd10 {
+                    regulator-name = "VD10";
+                };
+                ldo: regulator-voutl1 {
+                    regulator-name = "VOUTL1";
+                };
+                sw: regulator-vouts1 {
+                    regulator-name = "VOUTS1";
+                };
+            };
+        };
+    };
-- 
2.21.3


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =] 

[PATCH v5 2/4] mfd: Support ROHM BD9576MUF and BD9573MUF

[Matti Vaittinen]

Add core support for ROHM BD9576MUF and BD9573MUF PMICs which are
mainly used to power the R-Car series processors.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---
 drivers/mfd/Kconfig              |  11 ++++
 drivers/mfd/Makefile             |   1 +
 drivers/mfd/rohm-bd9576.c        | 108 +++++++++++++++++++++++++++++++
 include/linux/mfd/rohm-bd957x.h  |  59 +++++++++++++++++
 include/linux/mfd/rohm-generic.h |   2 +
 5 files changed, 181 insertions(+)
 create mode 100644 drivers/mfd/rohm-bd9576.c
 create mode 100644 include/linux/mfd/rohm-bd957x.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 8b99a13669bf..dcb2b14a570e 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2010,6 +2010,17 @@ config MFD_ROHM_BD71828
 	  Also included is a Coulomb counter, a real-time clock (RTC), and
 	  a 32.768 kHz clock gate.
 
+config MFD_ROHM_BD957XMUF
+	tristate "ROHM BD9576MUF and BD9573MUF Power Management ICs"
+	depends on I2C=y
+	depends on OF
+	select REGMAP_I2C
+	select MFD_CORE
+	help
+	  Select this option to get support for the ROHM BD9576MUF and
+	  BD9573MUF Power Management ICs. BD9576 and BD9573 are primarily
+	  designed to be used to power R-Car series processors.
+
 config MFD_STM32_LPTIMER
 	tristate "Support for STM32 Low-Power Timer"
 	depends on (ARCH_STM32 && OF) || COMPILE_TEST
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 1780019d2474..837f68c9f336 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -261,6 +261,7 @@ obj-$(CONFIG_RAVE_SP_CORE)	+= rave-sp.o
 obj-$(CONFIG_MFD_ROHM_BD70528)	+= rohm-bd70528.o
 obj-$(CONFIG_MFD_ROHM_BD71828)	+= rohm-bd71828.o
 obj-$(CONFIG_MFD_ROHM_BD718XX)	+= rohm-bd718x7.o
+obj-$(CONFIG_MFD_ROHM_BD957XMUF)	+= rohm-bd9576.o
 obj-$(CONFIG_MFD_STMFX) 	+= stmfx.o
 obj-$(CONFIG_MFD_KHADAS_MCU) 	+= khadas-mcu.o
 
diff --git a/drivers/mfd/rohm-bd9576.c b/drivers/mfd/rohm-bd9576.c
new file mode 100644
index 000000000000..f4dd9e438427
--- /dev/null
+++ b/drivers/mfd/rohm-bd9576.c
@@ -0,0 +1,108 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Copyright (C) 2020 ROHM Semiconductors
+//
+// ROHM BD9576MUF and BD9573MUF PMIC driver
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/rohm-bd957x.h>
+#include <linux/mfd/rohm-generic.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+static struct mfd_cell bd9573_mfd_cells[] = {
+	{ .name = "bd9573-pmic", },
+	{ .name = "bd9576-wdt", },
+};
+
+static struct mfd_cell bd9576_mfd_cells[] = {
+	{ .name = "bd9576-pmic", },
+	{ .name = "bd9576-wdt", },
+};
+
+static const struct regmap_range volatile_ranges[] = {
+	regmap_reg_range(BD957X_REG_SMRB_ASSERT, BD957X_REG_SMRB_ASSERT),
+	regmap_reg_range(BD957X_REG_PMIC_INTERNAL_STAT,
+			 BD957X_REG_PMIC_INTERNAL_STAT),
+	regmap_reg_range(BD957X_REG_INT_THERM_STAT, BD957X_REG_INT_THERM_STAT),
+	regmap_reg_range(BD957X_REG_INT_OVP_STAT, BD957X_REG_INT_SYS_STAT),
+	regmap_reg_range(BD957X_REG_INT_MAIN_STAT, BD957X_REG_INT_MAIN_STAT),
+};
+
+static const struct regmap_access_table volatile_regs = {
+	.yes_ranges = &volatile_ranges[0],
+	.n_yes_ranges = ARRAY_SIZE(volatile_ranges),
+};
+
+static struct regmap_config bd957x_regmap = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.volatile_table = &volatile_regs,
+	.max_register = BD957X_MAX_REGISTER,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static int bd957x_i2c_probe(struct i2c_client *i2c,
+			     const struct i2c_device_id *id)
+{
+	int ret;
+	struct regmap *regmap;
+	struct mfd_cell *mfd;
+	int cells;
+	unsigned long chip_type;
+
+	chip_type = (unsigned long)of_device_get_match_data(&i2c->dev);
+
+	switch (chip_type) {
+	case ROHM_CHIP_TYPE_BD9576:
+		mfd = bd9576_mfd_cells;
+		cells = ARRAY_SIZE(bd9576_mfd_cells);
+		break;
+	case ROHM_CHIP_TYPE_BD9573:
+		mfd = bd9573_mfd_cells;
+		cells = ARRAY_SIZE(bd9573_mfd_cells);
+		break;
+	default:
+		dev_err(&i2c->dev, "Unknown device type");
+		return -EINVAL;
+	}
+
+	regmap = devm_regmap_init_i2c(i2c, &bd957x_regmap);
+	if (IS_ERR(regmap)) {
+		dev_err(&i2c->dev, "Failed to initialize Regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO, mfd, cells,
+				   NULL, 0, NULL);
+	if (ret)
+		dev_err(&i2c->dev, "Failed to create subdevices\n");
+
+	return ret;
+}
+
+static const struct of_device_id bd957x_of_match[] = {
+	{ .compatible = "rohm,bd9576", .data = (void *)ROHM_CHIP_TYPE_BD9576, },
+	{ .compatible = "rohm,bd9573", .data = (void *)ROHM_CHIP_TYPE_BD9573, },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, bd957x_of_match);
+
+static struct i2c_driver bd957x_drv = {
+	.driver = {
+		.name = "rohm-bd957x",
+		.of_match_table = bd957x_of_match,
+	},
+	.probe = &bd957x_i2c_probe,
+};
+module_i2c_driver(bd957x_drv);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("ROHM BD9576MUF and BD9573MUF Power Management IC driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/rohm-bd957x.h b/include/linux/mfd/rohm-bd957x.h
new file mode 100644
index 000000000000..3e7ca6fe5d4f
--- /dev/null
+++ b/include/linux/mfd/rohm-bd957x.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2020 ROHM Semiconductors */
+
+#ifndef __LINUX_MFD_BD957X_H__
+#define __LINUX_MFD_BD957X_H__
+
+enum {
+	BD957X_VD50,
+	BD957X_VD18,
+	BD957X_VDDDR,
+	BD957X_VD10,
+	BD957X_VOUTL1,
+	BD957X_VOUTS1,
+};
+
+#define BD957X_REG_SMRB_ASSERT		0x15
+#define BD957X_REG_PMIC_INTERNAL_STAT	0x20
+#define BD957X_REG_INT_THERM_STAT	0x23
+#define BD957X_REG_INT_THERM_MASK 0x24
+#define BD957X_REG_INT_OVP_STAT 0x25
+#define BD957X_REG_INT_SCP_STAT 0x26
+#define BD957X_REG_INT_OCP_STAT 0x27
+#define BD957X_REG_INT_OVD_STAT 0x28
+#define BD957X_REG_INT_UVD_STAT 0x29
+#define BD957X_REG_INT_UVP_STAT 0x2a
+#define BD957X_REG_INT_SYS_STAT 0x2b
+#define BD957X_REG_INT_SYS_MASK 0x2c
+#define BD957X_REG_INT_MAIN_STAT 0x30
+#define BD957X_REG_INT_MAIN_MASK 0x31
+
+#define BD957X_REG_WDT_CONF 0x16
+
+#define BD957X_REG_POW_TRIGGER1 0x41
+#define BD957X_REG_POW_TRIGGER2 0x42
+#define BD957X_REG_POW_TRIGGER3 0x43
+#define BD957X_REG_POW_TRIGGER4 0x44
+#define BD957X_REG_POW_TRIGGERL1 0x45
+#define BD957X_REG_POW_TRIGGERS1 0x46
+
+#define BD957X_REGULATOR_EN_MASK 0xff
+#define BD957X_REGULATOR_DIS_VAL 0xff
+
+#define BD957X_VSEL_REG_MASK	0xff
+
+#define BD957X_MASK_VOUT1_TUNE	0x87
+#define BD957X_MASK_VOUT2_TUNE	0x87
+#define BD957X_MASK_VOUT3_TUNE	0x1f
+#define BD957X_MASK_VOUT4_TUNE	0x1f
+#define BD957X_MASK_VOUTL1_TUNE	0x87
+
+#define BD957X_REG_VOUT1_TUNE	0x50
+#define BD957X_REG_VOUT2_TUNE	0x53
+#define BD957X_REG_VOUT3_TUNE	0x56
+#define BD957X_REG_VOUT4_TUNE	0x59
+#define BD957X_REG_VOUTL1_TUNE	0x5c
+
+#define BD957X_MAX_REGISTER 0x61
+
+#endif
diff --git a/include/linux/mfd/rohm-generic.h b/include/linux/mfd/rohm-generic.h
index 4283b5b33e04..58b4f1a0f4af 100644
--- a/include/linux/mfd/rohm-generic.h
+++ b/include/linux/mfd/rohm-generic.h
@@ -12,6 +12,8 @@ enum rohm_chip_type {
 	ROHM_CHIP_TYPE_BD71847,
 	ROHM_CHIP_TYPE_BD70528,
 	ROHM_CHIP_TYPE_BD71828,
+	ROHM_CHIP_TYPE_BD9576,
+	ROHM_CHIP_TYPE_BD9573,
 	ROHM_CHIP_TYPE_AMOUNT
 };
 
-- 
2.21.3


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =] 

[PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF

[Matti Vaittinen]

Add Watchdog support for ROHM BD9576MUF and BD9573MUF PMICs which are
mainly used to power the R-Car series processors. The watchdog is
pinged using a GPIO and enabled using another GPIO. Additionally
watchdog time-out can be configured to HW prior starting the watchdog.
Watchdog timeout can be configured to detect only delayed ping or in
a window mode where also too fast pings are detected.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/watchdog/Kconfig      |  13 ++
 drivers/watchdog/Makefile     |   1 +
 drivers/watchdog/bd9576_wdt.c | 290 ++++++++++++++++++++++++++++++++++
 3 files changed, 304 insertions(+)
 create mode 100644 drivers/watchdog/bd9576_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index fd7968635e6d..d5fec1bdf23e 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -172,6 +172,19 @@ config BD70528_WATCHDOG
 	  Alternatively say M to compile the driver as a module,
 	  which will be called bd70528_wdt.
 
+config BD957XMUF_WATCHDOG
+	tristate "ROHM BD9576MUF and BD9573MUF PMIC Watchdog"
+	depends on MFD_ROHM_BD957XMUF
+	select WATCHDOG_CORE
+	help
+	  Support for the watchdog in the ROHM BD9576 and BD9573 PMICs.
+	  These PMIC ICs contain watchdog block which can be configured
+	  to toggle reset line if SoC fails to ping watchdog via GPIO.
+
+	  Say Y here to include support for the ROHM BD9576 or BD9573
+	  watchdog. Alternatively say M to compile the driver as a module,
+	  which will be called bd9576_wdt.
+
 config DA9052_WATCHDOG
 	tristate "Dialog DA9052 Watchdog"
 	depends on PMIC_DA9052 || COMPILE_TEST
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 071a2e50be98..54f39883f3ac 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -209,6 +209,7 @@ obj-$(CONFIG_XEN_WDT) += xen_wdt.o
 
 # Architecture Independent
 obj-$(CONFIG_BD70528_WATCHDOG) += bd70528_wdt.o
+obj-$(CONFIG_BD957XMUF_WATCHDOG) += bd9576_wdt.o
 obj-$(CONFIG_DA9052_WATCHDOG) += da9052_wdt.o
 obj-$(CONFIG_DA9055_WATCHDOG) += da9055_wdt.o
 obj-$(CONFIG_DA9062_WATCHDOG) += da9062_wdt.o
diff --git a/drivers/watchdog/bd9576_wdt.c b/drivers/watchdog/bd9576_wdt.c
new file mode 100644
index 000000000000..afef19ce01be
--- /dev/null
+++ b/drivers/watchdog/bd9576_wdt.c
@@ -0,0 +1,290 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 ROHM Semiconductors
+ *
+ * ROHM BD9576MUF and BD9573MUF Watchdog driver
+ */
+
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mfd/rohm-bd957x.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/watchdog.h>
+
+static bool nowayout;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout,
+		"Watchdog cannot be stopped once started (default=\"false\")");
+
+#define HW_MARGIN_MIN 2
+#define HW_MARGIN_MAX 4416
+#define BD957X_WDT_DEFAULT_MARGIN 4416
+
+struct bd9576_wdt_priv {
+	struct gpio_desc	*gpiod_ping;
+	struct gpio_desc	*gpiod_en;
+	struct device		*dev;
+	struct regmap		*regmap;
+	bool			always_running;
+	struct watchdog_device	wdd;
+};
+
+static void bd9576_wdt_disable(struct bd9576_wdt_priv *priv)
+{
+	gpiod_set_value_cansleep(priv->gpiod_en, 0);
+}
+
+static int bd9576_wdt_ping(struct watchdog_device *wdd)
+{
+	struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	/* Pulse */
+	gpiod_set_value_cansleep(priv->gpiod_ping, 1);
+	gpiod_set_value_cansleep(priv->gpiod_ping, 0);
+
+	return 0;
+}
+
+static int bd9576_wdt_start(struct watchdog_device *wdd)
+{
+	struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	gpiod_set_value_cansleep(priv->gpiod_en, 1);
+
+	return bd9576_wdt_ping(wdd);
+}
+
+static int bd9576_wdt_stop(struct watchdog_device *wdd)
+{
+	struct bd9576_wdt_priv *priv = watchdog_get_drvdata(wdd);
+
+	if (!priv->always_running)
+		bd9576_wdt_disable(priv);
+	else
+		set_bit(WDOG_HW_RUNNING, &wdd->status);
+
+	return 0;
+}
+
+static const struct watchdog_info bd957x_wdt_ident = {
+	.options	= WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
+			  WDIOF_SETTIMEOUT,
+	.identity	= "BD957x Watchdog",
+};
+
+static const struct watchdog_ops bd957x_wdt_ops = {
+	.owner		= THIS_MODULE,
+	.start		= bd9576_wdt_start,
+	.stop		= bd9576_wdt_stop,
+	.ping		= bd9576_wdt_ping,
+};
+
+/* Unit is hundreds of uS */
+#define FASTNG_MIN 23
+
+static int find_closest_fast(int target, int *sel, int *val)
+{
+	int i;
+	int window = FASTNG_MIN;
+
+	for (i = 0; i < 8 && window < target; i++)
+		window <<= 1;
+
+	*val = window;
+	*sel = i;
+
+	if (i == 8)
+		return -EINVAL;
+
+	return 0;
+
+}
+
+static int find_closest_slow_by_fast(int fast_val, int target, int *slowsel)
+{
+	int sel;
+	static const int multipliers[] = {2, 3, 7, 15};
+
+	for (sel = 0; sel < ARRAY_SIZE(multipliers) &&
+	     multipliers[sel] * fast_val < target; sel++)
+		;
+
+	if (sel == ARRAY_SIZE(multipliers))
+		return -EINVAL;
+
+	*slowsel = sel;
+
+	return 0;
+}
+
+static int find_closest_slow(int target, int *slow_sel, int *fast_sel)
+{
+	static const int multipliers[] = {2, 3, 7, 15};
+	int i, j;
+	int val = 0;
+	int window = FASTNG_MIN;
+
+	for (i = 0; i < 8; i++) {
+		for (j = 0; j < ARRAY_SIZE(multipliers); j++) {
+			int slow;
+
+			slow = window * multipliers[j];
+			if (slow >= target && (!val || slow < val)) {
+				val = slow;
+				*fast_sel = i;
+				*slow_sel = j;
+			}
+		}
+		window <<= 1;
+	}
+	if (!val)
+		return -EINVAL;
+
+	return 0;
+}
+
+#define BD957X_WDG_TYPE_WINDOW BIT(5)
+#define BD957X_WDG_TYPE_SLOW 0
+#define BD957X_WDG_TYPE_MASK BIT(5)
+#define BD957X_WDG_NG_RATIO_MASK 0x18
+#define BD957X_WDG_FASTNG_MASK 0x7
+
+static int bd957x_set_wdt_mode(struct bd9576_wdt_priv *priv, int hw_margin,
+			       int hw_margin_min)
+{
+	int ret, fastng, slowng, type, reg, mask;
+	struct device *dev = priv->dev;
+
+	/* convert to 100uS */
+	hw_margin *= 10;
+	hw_margin_min *= 10;
+	if (hw_margin_min) {
+		int min;
+
+		type = BD957X_WDG_TYPE_WINDOW;
+		dev_dbg(dev, "Setting type WINDOW 0x%x\n", type);
+		ret = find_closest_fast(hw_margin_min, &fastng, &min);
+		if (ret) {
+			dev_err(dev, "bad WDT window for fast timeout\n");
+			return ret;
+		}
+
+		ret = find_closest_slow_by_fast(min, hw_margin, &slowng);
+		if (ret) {
+			dev_err(dev, "bad WDT window\n");
+			return ret;
+		}
+
+	} else {
+		type = BD957X_WDG_TYPE_SLOW;
+		dev_dbg(dev, "Setting type SLOW 0x%x\n", type);
+		ret = find_closest_slow(hw_margin, &slowng, &fastng);
+		if (ret) {
+			dev_err(dev, "bad WDT window\n");
+			return ret;
+		}
+	}
+
+	slowng <<= ffs(BD957X_WDG_NG_RATIO_MASK) - 1;
+	reg = type | slowng | fastng;
+	mask = BD957X_WDG_TYPE_MASK | BD957X_WDG_NG_RATIO_MASK |
+	       BD957X_WDG_FASTNG_MASK;
+	ret = regmap_update_bits(priv->regmap, BD957X_REG_WDT_CONF,
+				 mask, reg);
+
+	return ret;
+}
+
+static int bd9576_wdt_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->parent->of_node;
+	struct bd9576_wdt_priv *priv;
+	u32 hw_margin[2];
+	u32 hw_margin_max = BD957X_WDT_DEFAULT_MARGIN, hw_margin_min = 0;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, priv);
+
+	priv->dev = dev;
+	priv->regmap = dev_get_regmap(dev->parent, NULL);
+	if (!priv->regmap) {
+		dev_err(dev, "No regmap found\n");
+		return -ENODEV;
+	}
+
+	priv->gpiod_en = devm_gpiod_get_from_of_node(dev, dev->parent->of_node,
+						     "rohm,watchdog-enable-gpios",
+						     0, GPIOD_OUT_LOW,
+						     "watchdog-enable");
+	if (IS_ERR(priv->gpiod_en))
+		return dev_err_probe(dev, PTR_ERR(priv->gpiod_en),
+			      "getting watchdog-enable GPIO failed\n");
+
+	priv->gpiod_ping = devm_gpiod_get_from_of_node(dev, dev->parent->of_node,
+						     "rohm,watchdog-ping-gpios",
+						     0, GPIOD_OUT_LOW,
+						     "watchdog-ping");
+	if (IS_ERR(priv->gpiod_ping))
+		return dev_err_probe(dev, PTR_ERR(priv->gpiod_ping),
+				     "getting watchdog-ping GPIO failed\n");
+
+	ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-ms",
+						  &hw_margin[0], 1, 2);
+	if (ret < 0 && ret != -EINVAL)
+		return ret;
+
+	if (ret == 1)
+		hw_margin_max = hw_margin[0];
+
+	if (ret == 2) {
+		hw_margin_max = hw_margin[1];
+		hw_margin_min = hw_margin[0];
+	}
+
+	ret = bd957x_set_wdt_mode(priv, hw_margin_max, hw_margin_min);
+	if (ret)
+		return ret;
+
+	priv->always_running = of_property_read_bool(np, "always-running");
+
+	watchdog_set_drvdata(&priv->wdd, priv);
+
+	priv->wdd.info			= &bd957x_wdt_ident;
+	priv->wdd.ops			= &bd957x_wdt_ops;
+	priv->wdd.min_hw_heartbeat_ms	= hw_margin_min;
+	priv->wdd.max_hw_heartbeat_ms	= hw_margin_max;
+	priv->wdd.parent		= dev;
+	priv->wdd.timeout		= (hw_margin_max / 2) * 1000;
+
+	watchdog_init_timeout(&priv->wdd, 0, dev);
+	watchdog_set_nowayout(&priv->wdd, nowayout);
+
+	watchdog_stop_on_reboot(&priv->wdd);
+
+	if (priv->always_running)
+		bd9576_wdt_start(&priv->wdd);
+
+	return devm_watchdog_register_device(dev, &priv->wdd);
+}
+
+static struct platform_driver bd9576_wdt_driver = {
+	.driver	= {
+		.name = "bd9576-wdt",
+	},
+	.probe	= bd9576_wdt_probe,
+};
+
+module_platform_driver(bd9576_wdt_driver);
+
+MODULE_AUTHOR("Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>");
+MODULE_DESCRIPTION("ROHM BD9576/BD9573 Watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:bd9576-wdt");
-- 
2.21.3


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =] 

[PATCH v5 4/4] MAINTAINERS: Add ROHM BD9576MUF and BD9573MUF drivers

[Matti Vaittinen]

Add maintainer entries for ROHM BD9576MUF and ROHM BD9573MUF drivers.
MFD, regulator and watchdog drivers were introduced for these PMICs.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
---
 MAINTAINERS | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index b516bb34a8d5..0bd788a94376 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15088,16 +15088,20 @@ F:	drivers/gpio/gpio-bd71828.c
 F:	drivers/mfd/rohm-bd70528.c
 F:	drivers/mfd/rohm-bd71828.c
 F:	drivers/mfd/rohm-bd718x7.c
+F:	drivers/mfd/rohm-bd9576.c
 F:	drivers/power/supply/bd70528-charger.c
 F:	drivers/regulator/bd70528-regulator.c
 F:	drivers/regulator/bd71828-regulator.c
 F:	drivers/regulator/bd718x7-regulator.c
+F:	drivers/regulator/bd9576-regulator.c
 F:	drivers/regulator/rohm-regulator.c
 F:	drivers/rtc/rtc-bd70528.c
 F:	drivers/watchdog/bd70528_wdt.c
+F:	drivers/watchdog/bd9576_wdt.c
 F:	include/linux/mfd/rohm-bd70528.h
 F:	include/linux/mfd/rohm-bd71828.h
 F:	include/linux/mfd/rohm-bd718x7.h
+F:	include/linux/mfd/rohm-bd957x.h
 F:	include/linux/mfd/rohm-generic.h
 F:	include/linux/mfd/rohm-shared.h
 
-- 
2.21.3


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =] 

Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF

[Vaittinen, Matti]

On Thu, 2020-11-05 at 13:38 +0200, Matti Vaittinen wrote:
> Add Watchdog support for ROHM BD9576MUF and BD9573MUF PMICs which are
> mainly used to power the R-Car series processors. The watchdog is
> pinged using a GPIO and enabled using another GPIO. Additionally
> watchdog time-out can be configured to HW prior starting the
> watchdog.
> Watchdog timeout can be configured to detect only delayed ping or in
> a window mode where also too fast pings are detected.
> 
> Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> ---
> 

//snip

> +	ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-
> ms",
> +						  &hw_margin[0], 1, 2);
> +	if (ret < 0 && ret != -EINVAL)
> +		return ret;
> +
> +	if (ret == 1)
> +		hw_margin_max = hw_margin[0];
> +
> +	if (ret == 2) {
> +		hw_margin_max = hw_margin[1];
> +		hw_margin_min = hw_margin[0];
> +	}
> +
> +	ret = bd957x_set_wdt_mode(priv, hw_margin_max, hw_margin_min);
> +	if (ret)
> +		return ret;
> +
> +	priv->always_running = of_property_read_bool(np, "always-
> running");
> +
> +	watchdog_set_drvdata(&priv->wdd, priv);
> +
> +	priv->wdd.info			= &bd957x_wdt_ident;
> +	priv->wdd.ops			= &bd957x_wdt_ops;
> +	priv->wdd.min_hw_heartbeat_ms	= hw_margin_min;
> +	priv->wdd.max_hw_heartbeat_ms	= hw_margin_max;
> +	priv->wdd.parent		= dev;
> +	priv->wdd.timeout		= (hw_margin_max / 2) * 1000;

Hmm. Just noticed this value does not make sense, right?
Maximum hw_margin is 4416 ms. If I read this correctly timeout should
be in seconds -  so result is around 2 000 000 seconds here. I think it
is useless value...

Perhaps
	priv->wdd.timeout		= (hw_margin_max / 2) / 1000;
	if (!priv->wdd.timeout)
		priv->wdd.timeout = 1;
would be more appropriate.

I need to do some testing when I get the HW at my hands - please don't
apply this patch just yet. I will respin this after some testing - or
if other patches are applied then I will just send this one alone.

Sorry for the hassle...

--Matti

--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~

Simon says - in Latin please.
"non cogito me" dixit Rene Descarte, deinde evanescavit

(Thanks for the translation Simon)

Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF

[Guenter Roeck]

On 11/11/20 6:01 AM, Vaittinen, Matti wrote:
> On Thu, 2020-11-05 at 13:38 +0200, Matti Vaittinen wrote:
>> Add Watchdog support for ROHM BD9576MUF and BD9573MUF PMICs which are
>> mainly used to power the R-Car series processors. The watchdog is
>> pinged using a GPIO and enabled using another GPIO. Additionally
>> watchdog time-out can be configured to HW prior starting the
>> watchdog.
>> Watchdog timeout can be configured to detect only delayed ping or in
>> a window mode where also too fast pings are detected.
>>
>> Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
>> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>> ---
>>
> 
> //snip
> 
>> +	ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-
>> ms",
>> +						  &hw_margin[0], 1, 2);
>> +	if (ret < 0 && ret != -EINVAL)
>> +		return ret;
>> +
>> +	if (ret == 1)
>> +		hw_margin_max = hw_margin[0];
>> +
>> +	if (ret == 2) {
>> +		hw_margin_max = hw_margin[1];
>> +		hw_margin_min = hw_margin[0];
>> +	}
>> +
>> +	ret = bd957x_set_wdt_mode(priv, hw_margin_max, hw_margin_min);
>> +	if (ret)
>> +		return ret;
>> +
>> +	priv->always_running = of_property_read_bool(np, "always-
>> running");
>> +
>> +	watchdog_set_drvdata(&priv->wdd, priv);
>> +
>> +	priv->wdd.info			= &bd957x_wdt_ident;
>> +	priv->wdd.ops			= &bd957x_wdt_ops;
>> +	priv->wdd.min_hw_heartbeat_ms	= hw_margin_min;
>> +	priv->wdd.max_hw_heartbeat_ms	= hw_margin_max;
>> +	priv->wdd.parent		= dev;
>> +	priv->wdd.timeout		= (hw_margin_max / 2) * 1000;
> 
> Hmm. Just noticed this value does not make sense, right?
> Maximum hw_margin is 4416 ms. If I read this correctly timeout should
> be in seconds -  so result is around 2 000 000 seconds here. I think it
> is useless value...
> 
> Perhaps
> 	priv->wdd.timeout		= (hw_margin_max / 2) / 1000;
> 	if (!priv->wdd.timeout)
> 		priv->wdd.timeout = 1;
> would be more appropriate.
> 

Yes. Good catch. Actually, since max_hw_heartbeat_ms is specified,
it can and should be a reasonable constant (like the usual 30 seconds).
It does not and should not be bound by max_hw_heartbeat_ms.

> I need to do some testing when I get the HW at my hands - please don't
> apply this patch just yet. I will respin this after some testing - or
> if other patches are applied then I will just send this one alone.
> 
> Sorry for the hassle...
> 
No worries. Thanks for noticing.

Guenter

> --Matti
> 
> --
> Matti Vaittinen, Linux device drivers
> ROHM Semiconductors, Finland SWDC
> Kiviharjunlenkki 1E
> 90220 OULU
> FINLAND
> 
> ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
> 
> Simon says - in Latin please.
> "non cogito me" dixit Rene Descarte, deinde evanescavit
> 
> (Thanks for the translation Simon)
> 

Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF

[Vaittinen, Matti]

On Wed, 2020-11-11 at 06:41 -0800, Guenter Roeck wrote:
> On 11/11/20 6:01 AM, Vaittinen, Matti wrote:
> > On Thu, 2020-11-05 at 13:38 +0200, Matti Vaittinen wrote:
> > > Add Watchdog support for ROHM BD9576MUF and BD9573MUF PMICs which
> > > are
> > > mainly used to power the R-Car series processors. The watchdog is
> > > pinged using a GPIO and enabled using another GPIO. Additionally
> > > watchdog time-out can be configured to HW prior starting the
> > > watchdog.
> > > Watchdog timeout can be configured to detect only delayed ping or
> > > in
> > > a window mode where also too fast pings are detected.
> > > 
> > > Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com
> > > >
> > > Reviewed-by: Guenter Roeck <linux@roeck-us.net>
> > > ---
> > > 
> > 
> > //snip
> > 
> > > +	ret = of_property_read_variable_u32_array(np, "rohm,hw-timeout-
> > > ms",
> > > +						  &hw_margin[0], 1, 2);
> > > +	if (ret < 0 && ret != -EINVAL)
> > > +		return ret;
> > > +
> > > +	if (ret == 1)
> > > +		hw_margin_max = hw_margin[0];
> > > +
> > > +	if (ret == 2) {
> > > +		hw_margin_max = hw_margin[1];
> > > +		hw_margin_min = hw_margin[0];
> > > +	}
> > > +
> > > +	ret = bd957x_set_wdt_mode(priv, hw_margin_max, hw_margin_min);
> > > +	if (ret)
> > > +		return ret;
> > > +
> > > +	priv->always_running = of_property_read_bool(np, "always-
> > > running");
> > > +
> > > +	watchdog_set_drvdata(&priv->wdd, priv);
> > > +
> > > +	priv->wdd.info			= &bd957x_wdt_ident;
> > > +	priv->wdd.ops			= &bd957x_wdt_ops;
> > > +	priv->wdd.min_hw_heartbeat_ms	= hw_margin_min;
> > > +	priv->wdd.max_hw_heartbeat_ms	= hw_margin_max;
> > > +	priv->wdd.parent		= dev;
> > > +	priv->wdd.timeout		= (hw_margin_max / 2) * 1000;
> > 
> > Hmm. Just noticed this value does not make sense, right?
> > Maximum hw_margin is 4416 ms. If I read this correctly timeout
> > should
> > be in seconds -  so result is around 2 000 000 seconds here. I
> > think it
> > is useless value...
> > 
> > Perhaps
> > 	priv->wdd.timeout		= (hw_margin_max / 2) / 1000;
> > 	if (!priv->wdd.timeout)
> > 		priv->wdd.timeout = 1;
> > would be more appropriate.
> > 
> 
> Yes. Good catch. Actually, since max_hw_heartbeat_ms is specified,
> it can and should be a reasonable constant (like the usual 30
> seconds).
> It does not and should not be bound by max_hw_heartbeat_ms.

Thanks for confirming this Guenter. I'd better admit I didn't
understand how the max_hw_heartbeat_ms works.

If I now read the code correctly, the "watchdog worker" takes care of
feeding for shorter periods than the "timeout" - and only stops
feeding max_hw_heartbeat_ms before timeout expires if userland has not
been feedin wdg. This is really cool approach for short(ish)
max_hw_heartbeat_ms configurations as user-space does not need to meet
"RT requirements". WDG framework is much more advanced that I knew :)
It's nice to learn!


--Matti

Re: [PATCH v5 3/4] wdt: Support wdt on ROHM BD9576MUF and BD9573MUF

[Guenter Roeck]

On Wed, Nov 11, 2020 at 03:15:17PM +0000, Vaittinen, Matti wrote:
[ ... ]
> > > > +
> > > > +	priv->wdd.info			= &bd957x_wdt_ident;
> > > > +	priv->wdd.ops			= &bd957x_wdt_ops;
> > > > +	priv->wdd.min_hw_heartbeat_ms	= hw_margin_min;
> > > > +	priv->wdd.max_hw_heartbeat_ms	= hw_margin_max;
> > > > +	priv->wdd.parent		= dev;
> > > > +	priv->wdd.timeout		= (hw_margin_max / 2) * 1000;
> > > 
> > > Hmm. Just noticed this value does not make sense, right?
> > > Maximum hw_margin is 4416 ms. If I read this correctly timeout
> > > should
> > > be in seconds -  so result is around 2 000 000 seconds here. I
> > > think it
> > > is useless value...
> > > 
> > > Perhaps
> > > 	priv->wdd.timeout		= (hw_margin_max / 2) / 1000;
> > > 	if (!priv->wdd.timeout)
> > > 		priv->wdd.timeout = 1;
> > > would be more appropriate.
> > > 
> > 
> > Yes. Good catch. Actually, since max_hw_heartbeat_ms is specified,
> > it can and should be a reasonable constant (like the usual 30
> > seconds).
> > It does not and should not be bound by max_hw_heartbeat_ms.
> 
> Thanks for confirming this Guenter. I'd better admit I didn't
> understand how the max_hw_heartbeat_ms works.
> 
> If I now read the code correctly, the "watchdog worker" takes care of
> feeding for shorter periods than the "timeout" - and only stops
> feeding max_hw_heartbeat_ms before timeout expires if userland has not
> been feedin wdg. This is really cool approach for short(ish)
> max_hw_heartbeat_ms configurations as user-space does not need to meet
> "RT requirements". WDG framework is much more advanced that I knew :)

Yes, exactly, that is the idea. Various drivers used to implement this
within the driver, so it just made sense to pull the functionality into
the watchdog core.

Thanks,
Guenter