diff options
Diffstat (limited to 'drivers/hwmon/lan966x-hwmon.c')
| -rw-r--r-- | drivers/hwmon/lan966x-hwmon.c | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/drivers/hwmon/lan966x-hwmon.c b/drivers/hwmon/lan966x-hwmon.c new file mode 100644 index 000000000..f41df053a --- /dev/null +++ b/drivers/hwmon/lan966x-hwmon.c @@ -0,0 +1,418 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/bitfield.h> +#include <linux/clk.h> +#include <linux/hwmon.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/polynomial.h> +#include <linux/regmap.h> + +/* + * The original translation formulae of the temperature (in degrees of Celsius) + * are as follows: + * + * T = -3.4627e-11*(N^4) + 1.1023e-7*(N^3) + -1.9165e-4*(N^2) + + * 3.0604e-1*(N^1) + -5.6197e1 + * + * where [-56.197, 136.402]C and N = [0, 1023]. + * + * They must be accordingly altered to be suitable for the integer arithmetics. + * The technique is called 'factor redistribution', which just makes sure the + * multiplications and divisions are made so to have a result of the operations + * within the integer numbers limit. In addition we need to translate the + * formulae to accept millidegrees of Celsius. Here what it looks like after + * the alterations: + * + * T = -34627e-12*(N^4) + 110230e-9*(N^3) + -191650e-6*(N^2) + + * 306040e-3*(N^1) + -56197 + * + * where T = [-56197, 136402]mC and N = [0, 1023]. + */ + +static const struct polynomial poly_N_to_temp = { + .terms = { + {4, -34627, 1000, 1}, + {3, 110230, 1000, 1}, + {2, -191650, 1000, 1}, + {1, 306040, 1000, 1}, + {0, -56197, 1, 1} + } +}; + +#define PVT_SENSOR_CTRL 0x0 /* unused */ +#define PVT_SENSOR_CFG 0x4 +#define SENSOR_CFG_CLK_CFG GENMASK(27, 20) +#define SENSOR_CFG_TRIM_VAL GENMASK(13, 9) +#define SENSOR_CFG_SAMPLE_ENA BIT(8) +#define SENSOR_CFG_START_CAPTURE BIT(7) +#define SENSOR_CFG_CONTINIOUS_MODE BIT(6) +#define SENSOR_CFG_PSAMPLE_ENA GENMASK(1, 0) +#define PVT_SENSOR_STAT 0x8 +#define SENSOR_STAT_DATA_VALID BIT(10) +#define SENSOR_STAT_DATA GENMASK(9, 0) + +#define FAN_CFG 0x0 +#define FAN_CFG_DUTY_CYCLE GENMASK(23, 16) +#define INV_POL BIT(3) +#define GATE_ENA BIT(2) +#define PWM_OPEN_COL_ENA BIT(1) +#define FAN_STAT_CFG BIT(0) +#define FAN_PWM_FREQ 0x4 +#define FAN_PWM_CYC_10US GENMASK(25, 15) +#define FAN_PWM_FREQ_FREQ GENMASK(14, 0) +#define FAN_CNT 0xc +#define FAN_CNT_DATA GENMASK(15, 0) + +#define LAN966X_PVT_CLK 1200000 /* 1.2 MHz */ + +struct lan966x_hwmon { + struct regmap *regmap_pvt; + struct regmap *regmap_fan; + struct clk *clk; + unsigned long clk_rate; +}; + +static int lan966x_hwmon_read_temp(struct device *dev, long *val) +{ + struct lan966x_hwmon *hwmon = dev_get_drvdata(dev); + unsigned int data; + int ret; + + ret = regmap_read(hwmon->regmap_pvt, PVT_SENSOR_STAT, &data); + if (ret < 0) + return ret; + + if (!(data & SENSOR_STAT_DATA_VALID)) + return -ENODATA; + + *val = polynomial_calc(&poly_N_to_temp, + FIELD_GET(SENSOR_STAT_DATA, data)); + + return 0; +} + +static int lan966x_hwmon_read_fan(struct device *dev, long *val) +{ + struct lan966x_hwmon *hwmon = dev_get_drvdata(dev); + unsigned int data; + int ret; + + ret = regmap_read(hwmon->regmap_fan, FAN_CNT, &data); + if (ret < 0) + return ret; + + /* + * Data is given in pulses per second. Assume two pulses + * per revolution. + */ + *val = FIELD_GET(FAN_CNT_DATA, data) * 60 / 2; + + return 0; +} + +static int lan966x_hwmon_read_pwm(struct device *dev, long *val) +{ + struct lan966x_hwmon *hwmon = dev_get_drvdata(dev); + unsigned int data; + int ret; + + ret = regmap_read(hwmon->regmap_fan, FAN_CFG, &data); + if (ret < 0) + return ret; + + *val = FIELD_GET(FAN_CFG_DUTY_CYCLE, data); + + return 0; +} + +static int lan966x_hwmon_read_pwm_freq(struct device *dev, long *val) +{ + struct lan966x_hwmon *hwmon = dev_get_drvdata(dev); + unsigned long tmp; + unsigned int data; + int ret; + + ret = regmap_read(hwmon->regmap_fan, FAN_PWM_FREQ, &data); + if (ret < 0) + return ret; + + /* + * Datasheet says it is sys_clk / 256 / pwm_freq. But in reality + * it is sys_clk / 256 / (pwm_freq + 1). + */ + data = FIELD_GET(FAN_PWM_FREQ_FREQ, data) + 1; + tmp = DIV_ROUND_CLOSEST(hwmon->clk_rate, 256); + *val = DIV_ROUND_CLOSEST(tmp, data); + + return 0; +} + +static int lan966x_hwmon_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + switch (type) { + case hwmon_temp: + return lan966x_hwmon_read_temp(dev, val); + case hwmon_fan: + return lan966x_hwmon_read_fan(dev, val); + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + return lan966x_hwmon_read_pwm(dev, val); + case hwmon_pwm_freq: + return lan966x_hwmon_read_pwm_freq(dev, val); + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } +} + +static int lan966x_hwmon_write_pwm(struct device *dev, long val) +{ + struct lan966x_hwmon *hwmon = dev_get_drvdata(dev); + + if (val < 0 || val > 255) + return -EINVAL; + + return regmap_update_bits(hwmon->regmap_fan, FAN_CFG, + FAN_CFG_DUTY_CYCLE, + FIELD_PREP(FAN_CFG_DUTY_CYCLE, val)); +} + +static int lan966x_hwmon_write_pwm_freq(struct device *dev, long val) +{ + struct lan966x_hwmon *hwmon = dev_get_drvdata(dev); + + if (val <= 0) + return -EINVAL; + + val = DIV_ROUND_CLOSEST(hwmon->clk_rate, val); + val = DIV_ROUND_CLOSEST(val, 256) - 1; + val = clamp_val(val, 0, FAN_PWM_FREQ_FREQ); + + return regmap_update_bits(hwmon->regmap_fan, FAN_PWM_FREQ, + FAN_PWM_FREQ_FREQ, + FIELD_PREP(FAN_PWM_FREQ_FREQ, val)); +} + +static int lan966x_hwmon_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + switch (type) { + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + return lan966x_hwmon_write_pwm(dev, val); + case hwmon_pwm_freq: + return lan966x_hwmon_write_pwm_freq(dev, val); + default: + return -EOPNOTSUPP; + } + default: + return -EOPNOTSUPP; + } +} + +static umode_t lan966x_hwmon_is_visible(const void *data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + umode_t mode = 0; + + switch (type) { + case hwmon_temp: + switch (attr) { + case hwmon_temp_input: + mode = 0444; + break; + default: + break; + } + break; + case hwmon_fan: + switch (attr) { + case hwmon_fan_input: + mode = 0444; + break; + default: + break; + } + break; + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + case hwmon_pwm_freq: + mode = 0644; + break; + default: + break; + } + break; + default: + break; + } + + return mode; +} + +static const struct hwmon_channel_info *lan966x_hwmon_info[] = { + HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ), + HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT), + HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT), + HWMON_CHANNEL_INFO(pwm, HWMON_PWM_INPUT | HWMON_PWM_FREQ), + NULL +}; + +static const struct hwmon_ops lan966x_hwmon_ops = { + .is_visible = lan966x_hwmon_is_visible, + .read = lan966x_hwmon_read, + .write = lan966x_hwmon_write, +}; + +static const struct hwmon_chip_info lan966x_hwmon_chip_info = { + .ops = &lan966x_hwmon_ops, + .info = lan966x_hwmon_info, +}; + +static void lan966x_hwmon_disable(void *data) +{ + struct lan966x_hwmon *hwmon = data; + + regmap_update_bits(hwmon->regmap_pvt, PVT_SENSOR_CFG, + SENSOR_CFG_SAMPLE_ENA | SENSOR_CFG_CONTINIOUS_MODE, + 0); +} + +static int lan966x_hwmon_enable(struct device *dev, + struct lan966x_hwmon *hwmon) +{ + unsigned int mask = SENSOR_CFG_CLK_CFG | + SENSOR_CFG_SAMPLE_ENA | + SENSOR_CFG_START_CAPTURE | + SENSOR_CFG_CONTINIOUS_MODE | + SENSOR_CFG_PSAMPLE_ENA; + unsigned int val; + unsigned int div; + int ret; + + /* enable continuous mode */ + val = SENSOR_CFG_SAMPLE_ENA | SENSOR_CFG_CONTINIOUS_MODE; + + /* set PVT clock to be between 1.15 and 1.25 MHz */ + div = DIV_ROUND_CLOSEST(hwmon->clk_rate, LAN966X_PVT_CLK); + val |= FIELD_PREP(SENSOR_CFG_CLK_CFG, div); + + ret = regmap_update_bits(hwmon->regmap_pvt, PVT_SENSOR_CFG, + mask, val); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, lan966x_hwmon_disable, hwmon); +} + +static struct regmap *lan966x_init_regmap(struct platform_device *pdev, + const char *name) +{ + struct regmap_config regmap_config = { + .reg_bits = 32, + .reg_stride = 4, + .val_bits = 32, + }; + void __iomem *base; + + base = devm_platform_ioremap_resource_byname(pdev, name); + if (IS_ERR(base)) + return ERR_CAST(base); + + regmap_config.name = name; + + return devm_regmap_init_mmio(&pdev->dev, base, ®map_config); +} + +static void lan966x_clk_disable(void *data) +{ + struct lan966x_hwmon *hwmon = data; + + clk_disable_unprepare(hwmon->clk); +} + +static int lan966x_clk_enable(struct device *dev, struct lan966x_hwmon *hwmon) +{ + int ret; + + ret = clk_prepare_enable(hwmon->clk); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, lan966x_clk_disable, hwmon); +} + +static int lan966x_hwmon_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct lan966x_hwmon *hwmon; + struct device *hwmon_dev; + int ret; + + hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL); + if (!hwmon) + return -ENOMEM; + + hwmon->clk = devm_clk_get(dev, NULL); + if (IS_ERR(hwmon->clk)) + return dev_err_probe(dev, PTR_ERR(hwmon->clk), + "failed to get clock\n"); + + ret = lan966x_clk_enable(dev, hwmon); + if (ret) + return dev_err_probe(dev, ret, "failed to enable clock\n"); + + hwmon->clk_rate = clk_get_rate(hwmon->clk); + + hwmon->regmap_pvt = lan966x_init_regmap(pdev, "pvt"); + if (IS_ERR(hwmon->regmap_pvt)) + return dev_err_probe(dev, PTR_ERR(hwmon->regmap_pvt), + "failed to get regmap for PVT registers\n"); + + hwmon->regmap_fan = lan966x_init_regmap(pdev, "fan"); + if (IS_ERR(hwmon->regmap_fan)) + return dev_err_probe(dev, PTR_ERR(hwmon->regmap_fan), + "failed to get regmap for fan registers\n"); + + ret = lan966x_hwmon_enable(dev, hwmon); + if (ret) + return dev_err_probe(dev, ret, "failed to enable sensor\n"); + + hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, + "lan966x_hwmon", hwmon, + &lan966x_hwmon_chip_info, NULL); + if (IS_ERR(hwmon_dev)) + return dev_err_probe(dev, PTR_ERR(hwmon_dev), + "failed to register hwmon device\n"); + + return 0; +} + +static const struct of_device_id lan966x_hwmon_of_match[] = { + { .compatible = "microchip,lan9668-hwmon" }, + {} +}; +MODULE_DEVICE_TABLE(of, lan966x_hwmon_of_match); + +static struct platform_driver lan966x_hwmon_driver = { + .probe = lan966x_hwmon_probe, + .driver = { + .name = "lan966x-hwmon", + .of_match_table = lan966x_hwmon_of_match, + }, +}; +module_platform_driver(lan966x_hwmon_driver); + +MODULE_DESCRIPTION("LAN966x Hardware Monitoring Driver"); +MODULE_AUTHOR("Michael Walle <michael@walle.cc>"); +MODULE_LICENSE("GPL"); |