diff options
Diffstat (limited to 'drivers/thermal/k3_bandgap.c')
| -rw-r--r-- | drivers/thermal/k3_bandgap.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/thermal/k3_bandgap.c b/drivers/thermal/k3_bandgap.c new file mode 100644 index 000000000000..35f41e8a0b75 --- /dev/null +++ b/drivers/thermal/k3_bandgap.c @@ -0,0 +1,264 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * TI Bandgap temperature sensor driver for K3 SoC Family + * + * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/ + */ + +#include <linux/err.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_platform.h> +#include <linux/pm_runtime.h> +#include <linux/thermal.h> +#include <linux/types.h> + +#define K3_VTM_DEVINFO_PWR0_OFFSET 0x4 +#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK 0xf0 +#define K3_VTM_TMPSENS0_CTRL_OFFSET 0x80 +#define K3_VTM_REGS_PER_TS 0x10 +#define K3_VTM_TS_STAT_DTEMP_MASK 0x3ff +#define K3_VTM_TMPSENS_CTRL_CBIASSEL BIT(0) +#define K3_VTM_TMPSENS_CTRL_SOC BIT(5) +#define K3_VTM_TMPSENS_CTRL_CLRZ BIT(6) +#define K3_VTM_TMPSENS_CTRL_CLKON_REQ BIT(7) + +#define K3_VTM_ADC_BEGIN_VAL 540 +#define K3_VTM_ADC_END_VAL 944 + +static const int k3_adc_to_temp[] = { + -40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600, -38200, + -37800, -37400, -37000, -36600, -36200, -35800, -35300, -34700, -34200, + -33800, -33400, -33000, -32600, -32200, -31800, -31400, -31000, -30600, + -30200, -29800, -29400, -29000, -28600, -28200, -27700, -27100, -26600, + -26200, -25800, -25400, -25000, -24600, -24200, -23800, -23400, -23000, + -22600, -22200, -21800, -21400, -21000, -20500, -19900, -19400, -19000, + -18600, -18200, -17800, -17400, -17000, -16600, -16200, -15800, -15400, + -15000, -14600, -14200, -13800, -13400, -13000, -12500, -11900, -11400, + -11000, -10600, -10200, -9800, -9400, -9000, -8600, -8200, -7800, -7400, + -7000, -6600, -6200, -5800, -5400, -5000, -4500, -3900, -3400, -3000, + -2600, -2200, -1800, -1400, -1000, -600, -200, 200, 600, 1000, 1400, + 1800, 2200, 2600, 3000, 3400, 3900, 4500, 5000, 5400, 5800, 6200, 6600, + 7000, 7400, 7800, 8200, 8600, 9000, 9400, 9800, 10200, 10600, 11000, + 11400, 11800, 12200, 12700, 13300, 13800, 14200, 14600, 15000, 15400, + 15800, 16200, 16600, 17000, 17400, 17800, 18200, 18600, 19000, 19400, + 19800, 20200, 20600, 21000, 21400, 21900, 22500, 23000, 23400, 23800, + 24200, 24600, 25000, 25400, 25800, 26200, 26600, 27000, 27400, 27800, + 28200, 28600, 29000, 29400, 29800, 30200, 30600, 31000, 31400, 31900, + 32500, 33000, 33400, 33800, 34200, 34600, 35000, 35400, 35800, 36200, + 36600, 37000, 37400, 37800, 38200, 38600, 39000, 39400, 39800, 40200, + 40600, 41000, 41400, 41800, 42200, 42600, 43100, 43700, 44200, 44600, + 45000, 45400, 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600, + 49000, 49400, 49800, 50200, 50600, 51000, 51400, 51800, 52200, 52600, + 53000, 53400, 53800, 54200, 54600, 55000, 55400, 55900, 56500, 57000, + 57400, 57800, 58200, 58600, 59000, 59400, 59800, 60200, 60600, 61000, + 61400, 61800, 62200, 62600, 63000, 63400, 63800, 64200, 64600, 65000, + 65400, 65800, 66200, 66600, 67000, 67400, 67800, 68200, 68600, 69000, + 69400, 69800, 70200, 70600, 71000, 71500, 72100, 72600, 73000, 73400, + 73800, 74200, 74600, 75000, 75400, 75800, 76200, 76600, 77000, 77400, + 77800, 78200, 78600, 79000, 79400, 79800, 80200, 80600, 81000, 81400, + 81800, 82200, 82600, 83000, 83400, 83800, 84200, 84600, 85000, 85400, + 85800, 86200, 86600, 87000, 87400, 87800, 88200, 88600, 89000, 89400, + 89800, 90200, 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400, + 93800, 94200, 94600, 95000, 95400, 95800, 96200, 96600, 97000, 97500, + 98100, 98600, 99000, 99400, 99800, 100200, 100600, 101000, 101400, + 101800, 102200, 102600, 103000, 103400, 103800, 104200, 104600, 105000, + 105400, 105800, 106200, 106600, 107000, 107400, 107800, 108200, 108600, + 109000, 109400, 109800, 110200, 110600, 111000, 111400, 111800, 112200, + 112600, 113000, 113400, 113800, 114200, 114600, 115000, 115400, 115800, + 116200, 116600, 117000, 117400, 117800, 118200, 118600, 119000, 119400, + 119800, 120200, 120600, 121000, 121400, 121800, 122200, 122600, 123000, + 123400, 123800, 124200, 124600, 124900, 125000, +}; + +struct k3_bandgap { + void __iomem *base; + const struct k3_bandgap_data *conf; +}; + +/* common data structures */ +struct k3_thermal_data { + struct thermal_zone_device *tzd; + struct k3_bandgap *bgp; + int sensor_id; + u32 ctrl_offset; + u32 stat_offset; +}; + +static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1, + unsigned int s2) +{ + int d01 = abs(s0 - s1); + int d02 = abs(s0 - s2); + int d12 = abs(s1 - s2); + + if (d01 <= d02 && d01 <= d12) + return (s0 + s1) / 2; + + if (d02 <= d01 && d02 <= d12) + return (s0 + s2) / 2; + + return (s1 + s2) / 2; +} + +static int k3_bgp_read_temp(struct k3_thermal_data *devdata, + int *temp) +{ + struct k3_bandgap *bgp; + unsigned int dtemp, s0, s1, s2; + + bgp = devdata->bgp; + + /* + * Errata is applicable for am654 pg 1.0 silicon. There + * is a variation of the order for 8-10 degree centigrade. + * Work around that by getting the average of two closest + * readings out of three readings everytime we want to + * report temperatures. + * + * Errata workaround. + */ + s0 = readl(bgp->base + devdata->stat_offset) & + K3_VTM_TS_STAT_DTEMP_MASK; + s1 = readl(bgp->base + devdata->stat_offset) & + K3_VTM_TS_STAT_DTEMP_MASK; + s2 = readl(bgp->base + devdata->stat_offset) & + K3_VTM_TS_STAT_DTEMP_MASK; + dtemp = vtm_get_best_value(s0, s1, s2); + + if (dtemp < K3_VTM_ADC_BEGIN_VAL || dtemp > K3_VTM_ADC_END_VAL) + return -EINVAL; + + *temp = k3_adc_to_temp[dtemp - K3_VTM_ADC_BEGIN_VAL]; + + return 0; +} + +static int k3_thermal_get_temp(void *devdata, int *temp) +{ + struct k3_thermal_data *data = devdata; + int ret = 0; + + ret = k3_bgp_read_temp(data, temp); + if (ret) + return ret; + + return ret; +} + +static const struct thermal_zone_of_device_ops k3_of_thermal_ops = { + .get_temp = k3_thermal_get_temp, +}; + +static const struct of_device_id of_k3_bandgap_match[]; + +static int k3_bandgap_probe(struct platform_device *pdev) +{ + int ret = 0, cnt, val, id; + struct resource *res; + struct device *dev = &pdev->dev; + struct k3_bandgap *bgp; + struct k3_thermal_data *data; + + if (ARRAY_SIZE(k3_adc_to_temp) != (K3_VTM_ADC_END_VAL + 1 - + K3_VTM_ADC_BEGIN_VAL)) + return -EINVAL; + + bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL); + if (!bgp) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + bgp->base = devm_ioremap_resource(dev, res); + if (IS_ERR(bgp->base)) + return PTR_ERR(bgp->base); + + pm_runtime_enable(dev); + ret = pm_runtime_get_sync(dev); + if (ret < 0) { + pm_runtime_put_noidle(dev); + pm_runtime_disable(dev); + return ret; + } + + /* Get the sensor count in the VTM */ + val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET); + cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK; + cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK); + + data = devm_kcalloc(dev, cnt, sizeof(*data), GFP_KERNEL); + if (!data) { + ret = -ENOMEM; + goto err_alloc; + } + + /* Register the thermal sensors */ + for (id = 0; id < cnt; id++) { + data[id].sensor_id = id; + data[id].bgp = bgp; + data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + + id * K3_VTM_REGS_PER_TS; + data[id].stat_offset = data[id].ctrl_offset + 0x8; + + val = readl(data[id].bgp->base + data[id].ctrl_offset); + val |= (K3_VTM_TMPSENS_CTRL_SOC | + K3_VTM_TMPSENS_CTRL_CLRZ | + K3_VTM_TMPSENS_CTRL_CLKON_REQ); + val &= ~K3_VTM_TMPSENS_CTRL_CBIASSEL; + writel(val, data[id].bgp->base + data[id].ctrl_offset); + + data[id].tzd = + devm_thermal_zone_of_sensor_register(dev, id, + &data[id], + &k3_of_thermal_ops); + if (IS_ERR(data[id].tzd)) { + dev_err(dev, "thermal zone device is NULL\n"); + ret = PTR_ERR(data[id].tzd); + goto err_alloc; + } + } + + platform_set_drvdata(pdev, bgp); + + return 0; + +err_alloc: + pm_runtime_put_sync(dev); + pm_runtime_disable(dev); + + return ret; +} + +static int k3_bandgap_remove(struct platform_device *pdev) +{ + pm_runtime_put_sync(&pdev->dev); + pm_runtime_disable(&pdev->dev); + + return 0; +} + +static const struct of_device_id of_k3_bandgap_match[] = { + { + .compatible = "ti,am654-vtm", + }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, of_k3_bandgap_match); + +static struct platform_driver k3_bandgap_sensor_driver = { + .probe = k3_bandgap_probe, + .remove = k3_bandgap_remove, + .driver = { + .name = "k3-soc-thermal", + .of_match_table = of_k3_bandgap_match, + }, +}; + +module_platform_driver(k3_bandgap_sensor_driver); + +MODULE_DESCRIPTION("K3 bandgap temperature sensor driver"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>"); |