[RFC 3/4] hwmon: add Gateworks System Controller support

Tim Harvey
2018-02-28T01:21:13Z

The Gateworks System Controller has a hwmon sub-component that exposes
up to 16 ADC's, some of which are temperature sensors, others which are
voltage inputs. The ADC configuration (register mapping and name) is
configured via device-tree and varies board to board.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
drivers/hwmon/Kconfig | 6 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/gsc-hwmon.c | 299 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 306 insertions(+)
create mode 100644 drivers/hwmon/gsc-hwmon.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 7ad0176..9cdc3cb 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -475,6 +475,12 @@ config SENSORS_F75375S
This driver can also be built as a module. If so, the module
will be called f75375s.

+config SENSORS_GSC
+ tristate "Gateworks System Controller ADC"
+ depends on MFD_GSC
+ help
+ Support for the Gateworks System Controller A/D converters.
+
config SENSORS_MC13783_ADC
tristate "Freescale MC13783/MC13892 ADC"
depends on MFD_MC13XXX
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 0fe489f..835a536 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -69,6 +69,7 @@ obj-$(CONFIG_SENSORS_G760A) += g760a.o
obj-$(CONFIG_SENSORS_G762) += g762.o
obj-$(CONFIG_SENSORS_GL518SM) += gl518sm.o
obj-$(CONFIG_SENSORS_GL520SM) += gl520sm.o
+obj-$(CONFIG_SENSORS_GSC) += gsc-hwmon.o
obj-$(CONFIG_SENSORS_GPIO_FAN) += gpio-fan.o
obj-$(CONFIG_SENSORS_HIH6130) += hih6130.o
obj-$(CONFIG_SENSORS_ULTRA45) += ultra45_env.o
diff --git a/drivers/hwmon/gsc-hwmon.c b/drivers/hwmon/gsc-hwmon.c
new file mode 100644
index 0000000..3e14bea
--- /dev/null
+++ b/drivers/hwmon/gsc-hwmon.c
@@ -0,0 +1,299 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Gateworks Corporation
+ */
+#define DEBUG
+
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/mfd/gsc.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+/* map channel to channel info */
+struct gsc_hwmon_ch {
+ u8 reg;
+ char name[32];
+};
+static struct gsc_hwmon_ch gsc_temp_ch[16];
+static struct gsc_hwmon_ch gsc_in_ch[16];
+static struct gsc_hwmon_ch gsc_fan_ch[5];
+
+static int
+gsc_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int ch, long *val)
+{
+ struct gsc_dev *gsc = dev_get_drvdata(dev);
+ int sz, ret;
+ u8 reg;
+ u8 buf[3];
+
+ dev_dbg(dev, "%s type=%d attr=%d ch=%d\n", __func__, type, attr, ch);
+ switch (type) {
+ case hwmon_in:
+ sz = 3;
+ reg = gsc_in_ch[ch].reg;
+ break;
+ case hwmon_temp:
+ sz = 2;
+ reg = gsc_temp_ch[ch].reg;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ ret = regmap_bulk_read(gsc->regmap_hwmon, reg, &buf, sz);
+ if (!ret) {
+ *val = 0;
+ while (sz-- > 0)
+ *val |= (buf[sz] << (8*sz));
+ if ((type == hwmon_temp) && *val > 0x8000)
+ *val -= 0xffff;
+ }
+
+ return ret;
+}
+
+static int
+gsc_hwmon_read_string(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int ch, const char **buf)
+{
+ dev_dbg(dev, "%s type=%d attr=%d ch=%d\n", __func__, type, attr, ch);
+ switch (type) {
+ case hwmon_in:
+ case hwmon_temp:
+ case hwmon_fan:
+ switch (attr) {
+ case hwmon_in_label:
+ *buf = gsc_in_ch[ch].name;
+ return 0;
+ break;
+ case hwmon_temp_label:
+ *buf = gsc_temp_ch[ch].name;
+ return 0;
+ break;
+ case hwmon_fan_label:
+ *buf = gsc_fan_ch[ch].name;
+ return 0;
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return -ENOTSUPP;
+}
+
+static int
+gsc_hwmon_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+ int ch, long val)
+{
+ struct gsc_dev *gsc = dev_get_drvdata(dev);
+ int ret;
+ u8 reg;
+ u8 buf[3];
+
+ dev_dbg(dev, "%s type=%d attr=%d ch=%d\n", __func__, type, attr, ch);
+ switch (type) {
+ case hwmon_fan:
+ buf[0] = val & 0xff;
+ buf[1] = (val >> 8) & 0xff;
+ reg = gsc_fan_ch[ch].reg;
+ ret = regmap_bulk_write(gsc->regmap_hwmon, reg, &buf, 2);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ break;
+ }
+
+ return ret;
+}
+
+static umode_t
+gsc_hwmon_is_visible(const void *_data, enum hwmon_sensor_types type, u32 attr,
+ int ch)
+{
+ const struct gsc_dev *gsc = _data;
+ struct device *dev = gsc->dev;
+ umode_t mode = 0;
+
+ switch (type) {
+ case hwmon_fan:
+ if (attr == hwmon_fan_input)
+ mode = (S_IRUGO | S_IWUSR);
+ break;
+ case hwmon_temp:
+ case hwmon_in:
+ mode = S_IRUGO;
+ break;
+ default:
+ break;
+ }
+ dev_dbg(dev, "%s type=%d attr=%d ch=%d mode=0x%x\n", __func__, type,
+ attr, ch, mode);
+
+ return mode;
+}
+
+static u32 gsc_in_config[] = {
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ HWMON_I_INPUT,
+ 0
+};
+static const struct hwmon_channel_info gsc_in = {
+ .type = hwmon_in,
+ .config = gsc_in_config,
+};
+
+static u32 gsc_temp_config[] = {
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ HWMON_T_INPUT,
+ 0
+};
+static const struct hwmon_channel_info gsc_temp = {
+ .type = hwmon_temp,
+ .config = gsc_temp_config,
+};
+
+static u32 gsc_fan_config[] = {
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ HWMON_F_INPUT,
+ 0,
+};
+static const struct hwmon_channel_info gsc_fan = {
+ .type = hwmon_fan,
+ .config = gsc_fan_config,
+};
+
+static const struct hwmon_channel_info *gsc_info[] = {
+ &gsc_temp,
+ &gsc_in,
+ &gsc_fan,
+ NULL
+};
+
+static const struct hwmon_ops gsc_hwmon_ops = {
+ .is_visible = gsc_hwmon_is_visible,
+ .read = gsc_hwmon_read,
+ .read_string = gsc_hwmon_read_string,
+ .write = gsc_hwmon_write,
+};
+
+static const struct hwmon_chip_info gsc_chip_info = {
+ .ops = &gsc_hwmon_ops,
+ .info = gsc_info,
+};
+
+static int gsc_hwmon_probe(struct platform_device *pdev)
+{
+ struct gsc_dev *gsc = dev_get_drvdata(pdev->dev.parent);
+ struct device_node *np;
+ struct device *hwmon;
+ int temp_count = 0;
+ int in_count = 0;
+ int fan_count = 0;
+ int ret;
+
+ dev_dbg(&pdev->dev, "%s\n", __func__);
+ np = of_get_next_child(pdev->dev.of_node, NULL);
+ while (np) {
+ u32 reg, type;
+ const char *label;
+
+ of_property_read_u32(np, "reg", &reg);
+ of_property_read_u32(np, "type", &type);
+ label = of_get_property(np, "label", NULL);
+ switch(type) {
+ case 0: /* temperature sensor */
+ gsc_temp_config[temp_count] = HWMON_T_INPUT |
+ HWMON_T_LABEL;
+ gsc_temp_ch[temp_count].reg = reg;
+ strncpy(gsc_temp_ch[temp_count].name, label, 32);
+ if (temp_count < ARRAY_SIZE(gsc_temp_config))
+ temp_count++;
+ break;
+ case 1: /* voltage sensor */
+ gsc_in_config[in_count] = HWMON_I_INPUT |
+ HWMON_I_LABEL;
+ gsc_in_ch[in_count].reg = reg;
+ strncpy(gsc_in_ch[in_count].name, label, 32);
+ if (in_count < ARRAY_SIZE(gsc_in_config))
+ in_count++;
+ break;
+ case 2: /* fan controller setpoint */
+ gsc_fan_config[fan_count] = HWMON_F_INPUT |
+ HWMON_F_LABEL;
+ gsc_fan_ch[fan_count].reg = reg;
+ strncpy(gsc_fan_ch[fan_count].name, label, 32);
+ if (fan_count < ARRAY_SIZE(gsc_fan_config))
+ fan_count++;
+ break;
+ }
+ np = of_get_next_child(pdev->dev.of_node, np);
+ }
+ /* terminate list */
+ gsc_in_config[in_count] = 0;
+ gsc_temp_config[temp_count] = 0;
+ gsc_fan_config[fan_count] = 0;
+
+ hwmon = devm_hwmon_device_register_with_info(&pdev->dev,
+ KBUILD_MODNAME, gsc,
+ &gsc_chip_info, NULL);
+ if (IS_ERR(hwmon)) {
+ ret = PTR_ERR(hwmon);
+ dev_err(&pdev->dev, "Unable to register hwmon device: %d\n",
+ ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id gsc_hwmon_of_match[] = {
+ { .compatible = "gw,gsc-hwmon", },
+ {}
+};
+
+static struct platform_driver gsc_hwmon_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = gsc_hwmon_of_match,
+ },
+ .probe = gsc_hwmon_probe,
+};
+
+module_platform_driver(gsc_hwmon_driver);
+
+MODULE_AUTHOR("Tim Harvey <tharvey@gateworks.com>");
+MODULE_DESCRIPTION("GSC hardware monitor driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4