diff options
author | Nick Hawkins <nick.hawkins@hpe.com> | 2023-01-03 23:36:50 +0300 |
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committer | Guenter Roeck <linux@roeck-us.net> | 2023-02-03 18:30:09 +0300 |
commit | 90905f7c40910a68677ea452ecf0023f31d6b08f (patch) | |
tree | 608b7ce5e618a89c6d19331196b4d32c80d31691 /drivers/hwmon/gxp-fan-ctrl.c | |
parent | 6d03bbff456befeccdd4d663177c4d6c75d0c4ff (diff) | |
download | linux-90905f7c40910a68677ea452ecf0023f31d6b08f.tar.xz |
hwmon: (gxp-fan-ctrl) Add GXP fan controller
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>
Link: https://lore.kernel.org/r/20230103203654.59322-2-nick.hawkins@hpe.com
[groeck: Improved alignment of defined, added missing include linux/bits.h]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon/gxp-fan-ctrl.c')
-rw-r--r-- | drivers/hwmon/gxp-fan-ctrl.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/drivers/hwmon/gxp-fan-ctrl.c b/drivers/hwmon/gxp-fan-ctrl.c new file mode 100644 index 000000000000..0e9225a8b805 --- /dev/null +++ b/drivers/hwmon/gxp-fan-ctrl.c @@ -0,0 +1,255 @@ +// 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"); |