--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2022 Hewlett-Packard Enterprise Development Company, L.P. */
+
+#include <linux/bits.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#define OFS_FAN_INST 0 /* Is 0 because plreg base will be set at INST */
+#define OFS_FAN_FAIL 2 /* Is 2 bytes after base */
+#define OFS_SEVSTAT 0 /* Is 0 because fn2 base will be set at SEVSTAT */
+#define POWER_BIT 24
+
+struct gxp_fan_ctrl_drvdata {
+ void __iomem *base;
+ void __iomem *plreg;
+ void __iomem *fn2;
+};
+
+static bool fan_installed(struct device *dev, int fan)
+{
+ struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
+ u8 val;
+
+ val = readb(drvdata->plreg + OFS_FAN_INST);
+
+ return !!(val & BIT(fan));
+}
+
+static long fan_failed(struct device *dev, int fan)
+{
+ struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
+ u8 val;
+
+ val = readb(drvdata->plreg + OFS_FAN_FAIL);
+
+ return !!(val & BIT(fan));
+}
+
+static long fan_enabled(struct device *dev, int fan)
+{
+ struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
+ u32 val;
+
+ /*
+ * Check the power status as if the platform is off the value
+ * reported for the PWM will be incorrect. Report fan as
+ * disabled.
+ */
+ val = readl(drvdata->fn2 + OFS_SEVSTAT);
+
+ return !!((val & BIT(POWER_BIT)) && fan_installed(dev, fan));
+}
+
+static int gxp_pwm_write(struct device *dev, u32 attr, int channel, long val)
+{
+ struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
+
+ switch (attr) {
+ case hwmon_pwm_input:
+ if (val > 255 || val < 0)
+ return -EINVAL;
+ writeb(val, drvdata->base + channel);
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int gxp_fan_ctrl_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ switch (type) {
+ case hwmon_pwm:
+ return gxp_pwm_write(dev, attr, channel, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int gxp_fan_read(struct device *dev, u32 attr, int channel, long *val)
+{
+ switch (attr) {
+ case hwmon_fan_enable:
+ *val = fan_enabled(dev, channel);
+ return 0;
+ case hwmon_fan_fault:
+ *val = fan_failed(dev, channel);
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int gxp_pwm_read(struct device *dev, u32 attr, int channel, long *val)
+{
+ struct gxp_fan_ctrl_drvdata *drvdata = dev_get_drvdata(dev);
+ u32 reg;
+
+ /*
+ * Check the power status of the platform. If the platform is off
+ * the value reported for the PWM will be incorrect. In this case
+ * report a PWM of zero.
+ */
+
+ reg = readl(drvdata->fn2 + OFS_SEVSTAT);
+
+ if (reg & BIT(POWER_BIT))
+ *val = fan_installed(dev, channel) ? readb(drvdata->base + channel) : 0;
+ else
+ *val = 0;
+
+ return 0;
+}
+
+static int gxp_fan_ctrl_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ switch (type) {
+ case hwmon_fan:
+ return gxp_fan_read(dev, attr, channel, val);
+ case hwmon_pwm:
+ return gxp_pwm_read(dev, attr, channel, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static umode_t gxp_fan_ctrl_is_visible(const void *_data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ umode_t mode = 0;
+
+ switch (type) {
+ case hwmon_fan:
+ switch (attr) {
+ case hwmon_fan_enable:
+ case hwmon_fan_fault:
+ mode = 0444;
+ break;
+ default:
+ break;
+ }
+ break;
+ case hwmon_pwm:
+ switch (attr) {
+ case hwmon_pwm_input:
+ mode = 0644;
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+
+ return mode;
+}
+
+static const struct hwmon_ops gxp_fan_ctrl_ops = {
+ .is_visible = gxp_fan_ctrl_is_visible,
+ .read = gxp_fan_ctrl_read,
+ .write = gxp_fan_ctrl_write,
+};
+
+static const struct hwmon_channel_info *gxp_fan_ctrl_info[] = {
+ HWMON_CHANNEL_INFO(fan,
+ HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_FAULT | HWMON_F_ENABLE,
+ HWMON_F_FAULT | HWMON_F_ENABLE),
+ HWMON_CHANNEL_INFO(pwm,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT,
+ HWMON_PWM_INPUT),
+ NULL
+};
+
+static const struct hwmon_chip_info gxp_fan_ctrl_chip_info = {
+ .ops = &gxp_fan_ctrl_ops,
+ .info = gxp_fan_ctrl_info,
+
+};
+
+static int gxp_fan_ctrl_probe(struct platform_device *pdev)
+{
+ struct gxp_fan_ctrl_drvdata *drvdata;
+ struct resource *res;
+ struct device *dev = &pdev->dev;
+ struct device *hwmon_dev;
+
+ drvdata = devm_kzalloc(dev, sizeof(struct gxp_fan_ctrl_drvdata),
+ GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ drvdata->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(drvdata->base))
+ return dev_err_probe(dev, PTR_ERR(drvdata->base),
+ "failed to map base\n");
+
+ drvdata->plreg = devm_platform_ioremap_resource_byname(pdev,
+ "pl");
+ if (IS_ERR(drvdata->plreg))
+ return dev_err_probe(dev, PTR_ERR(drvdata->plreg),
+ "failed to map plreg\n");
+
+ drvdata->fn2 = devm_platform_ioremap_resource_byname(pdev,
+ "fn2");
+ if (IS_ERR(drvdata->fn2))
+ return dev_err_probe(dev, PTR_ERR(drvdata->fn2),
+ "failed to map fn2\n");
+
+ hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
+ "hpe_gxp_fan_ctrl",
+ drvdata,
+ &gxp_fan_ctrl_chip_info,
+ NULL);
+
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct of_device_id gxp_fan_ctrl_of_match[] = {
+ { .compatible = "hpe,gxp-fan-ctrl", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, gxp_fan_ctrl_of_match);
+
+static struct platform_driver gxp_fan_ctrl_driver = {
+ .probe = gxp_fan_ctrl_probe,
+ .driver = {
+ .name = "gxp-fan-ctrl",
+ .of_match_table = gxp_fan_ctrl_of_match,
+ },
+};
+module_platform_driver(gxp_fan_ctrl_driver);
+
+MODULE_AUTHOR("Nick Hawkins <nick.hawkins@hpe.com>");
+MODULE_DESCRIPTION("HPE GXP fan controller");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-rpi.git / commitdiff