On Tue, Jan 03, 2023 at 02:36:50PM -0600, nick.hawkins@hpe.com wrote:

From: Nick Hawkins <nick.hawkins@hpe.com>

The GXP SoC can support up to 16 fans through the interface provided by
the CPLD. The current support is limited to 8 fans. The fans speeds are
controlled via 8 different PWMs which can vary in value from  0-255. The
fans are also capable of reporting if they have failed to the CPLD which
in turn reports the status to the GXP SoC.

Signed-off-by: Nick Hawkins <nick.hawkins@hpe.com>

Applied, with two minor changes (see below)

Use of BITS() asks for include of linux/bits.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

Tab-aligned defines

+
+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 [off-list ref]");
+MODULE_DESCRIPTION("HPE GXP fan controller");
+MODULE_LICENSE("GPL");