Thomas Gleixner | af873fc | 2019-05-28 09:57:21 -0700 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Baoyou Xie | 50fdd36 | 2017-02-07 08:56:41 +0800 | [diff] [blame] | 2 | /* |
| 3 | * ZTE's zx2967 family thermal sensor driver |
| 4 | * |
| 5 | * Copyright (C) 2017 ZTE Ltd. |
| 6 | * |
| 7 | * Author: Baoyou Xie <baoyou.xie@linaro.org> |
Baoyou Xie | 50fdd36 | 2017-02-07 08:56:41 +0800 | [diff] [blame] | 8 | */ |
| 9 | |
| 10 | #include <linux/clk.h> |
| 11 | #include <linux/device.h> |
| 12 | #include <linux/err.h> |
| 13 | #include <linux/iopoll.h> |
| 14 | #include <linux/module.h> |
| 15 | #include <linux/platform_device.h> |
| 16 | #include <linux/thermal.h> |
| 17 | |
| 18 | /* Power Mode: 0->low 1->high */ |
| 19 | #define ZX2967_THERMAL_POWER_MODE 0 |
| 20 | #define ZX2967_POWER_MODE_LOW 0 |
| 21 | #define ZX2967_POWER_MODE_HIGH 1 |
| 22 | |
| 23 | /* DCF Control Register */ |
| 24 | #define ZX2967_THERMAL_DCF 0x4 |
| 25 | #define ZX2967_DCF_EN BIT(1) |
| 26 | #define ZX2967_DCF_FREEZE BIT(0) |
| 27 | |
| 28 | /* Selection Register */ |
| 29 | #define ZX2967_THERMAL_SEL 0x8 |
| 30 | |
| 31 | /* Control Register */ |
| 32 | #define ZX2967_THERMAL_CTRL 0x10 |
| 33 | |
| 34 | #define ZX2967_THERMAL_READY BIT(12) |
| 35 | #define ZX2967_THERMAL_TEMP_MASK GENMASK(11, 0) |
| 36 | #define ZX2967_THERMAL_ID_MASK 0x18 |
| 37 | #define ZX2967_THERMAL_ID 0x10 |
| 38 | |
| 39 | #define ZX2967_GET_TEMP_TIMEOUT_US (100 * 1024) |
| 40 | |
| 41 | /** |
| 42 | * struct zx2967_thermal_priv - zx2967 thermal sensor private structure |
| 43 | * @tzd: struct thermal_zone_device where the sensor is registered |
| 44 | * @lock: prevents read sensor in parallel |
| 45 | * @clk_topcrm: topcrm clk structure |
| 46 | * @clk_apb: apb clk structure |
| 47 | * @regs: pointer to base address of the thermal sensor |
| 48 | */ |
| 49 | |
| 50 | struct zx2967_thermal_priv { |
| 51 | struct thermal_zone_device *tzd; |
| 52 | struct mutex lock; |
| 53 | struct clk *clk_topcrm; |
| 54 | struct clk *clk_apb; |
| 55 | void __iomem *regs; |
| 56 | struct device *dev; |
| 57 | }; |
| 58 | |
| 59 | static int zx2967_thermal_get_temp(void *data, int *temp) |
| 60 | { |
| 61 | void __iomem *regs; |
| 62 | struct zx2967_thermal_priv *priv = data; |
| 63 | u32 val; |
| 64 | int ret; |
| 65 | |
| 66 | if (!priv->tzd) |
| 67 | return -EAGAIN; |
| 68 | |
| 69 | regs = priv->regs; |
| 70 | mutex_lock(&priv->lock); |
| 71 | writel_relaxed(ZX2967_POWER_MODE_LOW, |
| 72 | regs + ZX2967_THERMAL_POWER_MODE); |
| 73 | writel_relaxed(ZX2967_DCF_EN, regs + ZX2967_THERMAL_DCF); |
| 74 | |
| 75 | val = readl_relaxed(regs + ZX2967_THERMAL_SEL); |
| 76 | val &= ~ZX2967_THERMAL_ID_MASK; |
| 77 | val |= ZX2967_THERMAL_ID; |
| 78 | writel_relaxed(val, regs + ZX2967_THERMAL_SEL); |
| 79 | |
| 80 | /* |
| 81 | * Must wait for a while, surely it's a bit odd. |
| 82 | * otherwise temperature value we got has a few deviation, even if |
| 83 | * the THERMAL_READY bit is set. |
| 84 | */ |
| 85 | usleep_range(100, 300); |
| 86 | ret = readx_poll_timeout(readl, regs + ZX2967_THERMAL_CTRL, |
| 87 | val, val & ZX2967_THERMAL_READY, 300, |
| 88 | ZX2967_GET_TEMP_TIMEOUT_US); |
| 89 | if (ret) { |
| 90 | dev_err(priv->dev, "Thermal sensor data timeout\n"); |
| 91 | goto unlock; |
| 92 | } |
| 93 | |
| 94 | writel_relaxed(ZX2967_DCF_FREEZE | ZX2967_DCF_EN, |
| 95 | regs + ZX2967_THERMAL_DCF); |
| 96 | val = readl_relaxed(regs + ZX2967_THERMAL_CTRL) |
| 97 | & ZX2967_THERMAL_TEMP_MASK; |
| 98 | writel_relaxed(ZX2967_POWER_MODE_HIGH, |
| 99 | regs + ZX2967_THERMAL_POWER_MODE); |
| 100 | |
| 101 | /* |
| 102 | * Calculate temperature |
| 103 | * In dts, slope is multiplied by 1000. |
| 104 | */ |
| 105 | *temp = DIV_ROUND_CLOSEST(((s32)val + priv->tzd->tzp->offset) * 1000, |
| 106 | priv->tzd->tzp->slope); |
| 107 | |
| 108 | unlock: |
| 109 | mutex_unlock(&priv->lock); |
| 110 | return ret; |
| 111 | } |
| 112 | |
Julia Lawall | e85c995 | 2017-08-08 17:08:58 +0200 | [diff] [blame] | 113 | static const struct thermal_zone_of_device_ops zx2967_of_thermal_ops = { |
Baoyou Xie | 50fdd36 | 2017-02-07 08:56:41 +0800 | [diff] [blame] | 114 | .get_temp = zx2967_thermal_get_temp, |
| 115 | }; |
| 116 | |
| 117 | static int zx2967_thermal_probe(struct platform_device *pdev) |
| 118 | { |
| 119 | struct zx2967_thermal_priv *priv; |
| 120 | struct resource *res; |
| 121 | int ret; |
| 122 | |
| 123 | priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); |
| 124 | if (!priv) |
| 125 | return -ENOMEM; |
| 126 | |
| 127 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 128 | priv->regs = devm_ioremap_resource(&pdev->dev, res); |
| 129 | if (IS_ERR(priv->regs)) |
| 130 | return PTR_ERR(priv->regs); |
| 131 | |
| 132 | priv->clk_topcrm = devm_clk_get(&pdev->dev, "topcrm"); |
| 133 | if (IS_ERR(priv->clk_topcrm)) { |
| 134 | ret = PTR_ERR(priv->clk_topcrm); |
| 135 | dev_err(&pdev->dev, "failed to get topcrm clock: %d\n", ret); |
| 136 | return ret; |
| 137 | } |
| 138 | |
| 139 | ret = clk_prepare_enable(priv->clk_topcrm); |
| 140 | if (ret) { |
| 141 | dev_err(&pdev->dev, "failed to enable topcrm clock: %d\n", |
| 142 | ret); |
| 143 | return ret; |
| 144 | } |
| 145 | |
| 146 | priv->clk_apb = devm_clk_get(&pdev->dev, "apb"); |
| 147 | if (IS_ERR(priv->clk_apb)) { |
| 148 | ret = PTR_ERR(priv->clk_apb); |
| 149 | dev_err(&pdev->dev, "failed to get apb clock: %d\n", ret); |
| 150 | goto disable_clk_topcrm; |
| 151 | } |
| 152 | |
| 153 | ret = clk_prepare_enable(priv->clk_apb); |
| 154 | if (ret) { |
| 155 | dev_err(&pdev->dev, "failed to enable apb clock: %d\n", |
| 156 | ret); |
| 157 | goto disable_clk_topcrm; |
| 158 | } |
| 159 | |
| 160 | mutex_init(&priv->lock); |
| 161 | priv->tzd = thermal_zone_of_sensor_register(&pdev->dev, |
| 162 | 0, priv, &zx2967_of_thermal_ops); |
| 163 | |
| 164 | if (IS_ERR(priv->tzd)) { |
| 165 | ret = PTR_ERR(priv->tzd); |
| 166 | dev_err(&pdev->dev, "failed to register sensor: %d\n", ret); |
| 167 | goto disable_clk_all; |
| 168 | } |
| 169 | |
| 170 | if (priv->tzd->tzp->slope == 0) { |
| 171 | thermal_zone_of_sensor_unregister(&pdev->dev, priv->tzd); |
| 172 | dev_err(&pdev->dev, "coefficients of sensor is invalid\n"); |
| 173 | ret = -EINVAL; |
| 174 | goto disable_clk_all; |
| 175 | } |
| 176 | |
| 177 | priv->dev = &pdev->dev; |
| 178 | platform_set_drvdata(pdev, priv); |
| 179 | |
| 180 | return 0; |
| 181 | |
| 182 | disable_clk_all: |
| 183 | clk_disable_unprepare(priv->clk_apb); |
| 184 | disable_clk_topcrm: |
| 185 | clk_disable_unprepare(priv->clk_topcrm); |
| 186 | return ret; |
| 187 | } |
| 188 | |
| 189 | static int zx2967_thermal_exit(struct platform_device *pdev) |
| 190 | { |
| 191 | struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev); |
| 192 | |
| 193 | thermal_zone_of_sensor_unregister(&pdev->dev, priv->tzd); |
| 194 | clk_disable_unprepare(priv->clk_topcrm); |
| 195 | clk_disable_unprepare(priv->clk_apb); |
| 196 | |
| 197 | return 0; |
| 198 | } |
| 199 | |
| 200 | static const struct of_device_id zx2967_thermal_id_table[] = { |
| 201 | { .compatible = "zte,zx296718-thermal" }, |
| 202 | {} |
| 203 | }; |
| 204 | MODULE_DEVICE_TABLE(of, zx2967_thermal_id_table); |
| 205 | |
| 206 | #ifdef CONFIG_PM_SLEEP |
| 207 | static int zx2967_thermal_suspend(struct device *dev) |
| 208 | { |
Wolfram Sang | 209d07e | 2018-10-21 22:00:52 +0200 | [diff] [blame] | 209 | struct zx2967_thermal_priv *priv = dev_get_drvdata(dev); |
Baoyou Xie | 50fdd36 | 2017-02-07 08:56:41 +0800 | [diff] [blame] | 210 | |
| 211 | if (priv && priv->clk_topcrm) |
| 212 | clk_disable_unprepare(priv->clk_topcrm); |
| 213 | |
| 214 | if (priv && priv->clk_apb) |
| 215 | clk_disable_unprepare(priv->clk_apb); |
| 216 | |
| 217 | return 0; |
| 218 | } |
| 219 | |
| 220 | static int zx2967_thermal_resume(struct device *dev) |
| 221 | { |
Wolfram Sang | 209d07e | 2018-10-21 22:00:52 +0200 | [diff] [blame] | 222 | struct zx2967_thermal_priv *priv = dev_get_drvdata(dev); |
Baoyou Xie | 50fdd36 | 2017-02-07 08:56:41 +0800 | [diff] [blame] | 223 | int error; |
| 224 | |
| 225 | error = clk_prepare_enable(priv->clk_topcrm); |
| 226 | if (error) |
| 227 | return error; |
| 228 | |
| 229 | error = clk_prepare_enable(priv->clk_apb); |
| 230 | if (error) { |
| 231 | clk_disable_unprepare(priv->clk_topcrm); |
| 232 | return error; |
| 233 | } |
| 234 | |
| 235 | return 0; |
| 236 | } |
| 237 | #endif |
| 238 | |
| 239 | static SIMPLE_DEV_PM_OPS(zx2967_thermal_pm_ops, |
| 240 | zx2967_thermal_suspend, zx2967_thermal_resume); |
| 241 | |
| 242 | static struct platform_driver zx2967_thermal_driver = { |
| 243 | .probe = zx2967_thermal_probe, |
| 244 | .remove = zx2967_thermal_exit, |
| 245 | .driver = { |
| 246 | .name = "zx2967_thermal", |
| 247 | .of_match_table = zx2967_thermal_id_table, |
| 248 | .pm = &zx2967_thermal_pm_ops, |
| 249 | }, |
| 250 | }; |
| 251 | module_platform_driver(zx2967_thermal_driver); |
| 252 | |
| 253 | MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>"); |
| 254 | MODULE_DESCRIPTION("ZTE zx2967 thermal driver"); |
| 255 | MODULE_LICENSE("GPL v2"); |