1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Platform driver for OneXPlayer, AOK ZOE, and Aya Neo Handhelds that expose 4 * fan reading and control via hwmon sysfs. 5 * 6 * Old OXP boards have the same DMI strings and they are told apart by 7 * the boot cpu vendor (Intel/AMD). Currently only AMD boards are 8 * supported but the code is made to be simple to add other handheld 9 * boards in the future. 10 * Fan control is provided via pwm interface in the range [0-255]. 11 * Old AMD boards use [0-100] as range in the EC, the written value is 12 * scaled to accommodate for that. Newer boards like the mini PRO and 13 * AOK ZOE are not scaled but have the same EC layout. 14 * 15 * Copyright (C) 2022 Joaquín I. Aramendía <samsagax@gmail.com> 16 */ 17 18 #include <linux/acpi.h> 19 #include <linux/dev_printk.h> 20 #include <linux/dmi.h> 21 #include <linux/hwmon.h> 22 #include <linux/init.h> 23 #include <linux/kernel.h> 24 #include <linux/module.h> 25 #include <linux/platform_device.h> 26 #include <linux/processor.h> 27 28 /* Handle ACPI lock mechanism */ 29 static u32 oxp_mutex; 30 31 #define ACPI_LOCK_DELAY_MS 500 32 33 static bool lock_global_acpi_lock(void) 34 { 35 return ACPI_SUCCESS(acpi_acquire_global_lock(ACPI_LOCK_DELAY_MS, &oxp_mutex)); 36 } 37 38 static bool unlock_global_acpi_lock(void) 39 { 40 return ACPI_SUCCESS(acpi_release_global_lock(oxp_mutex)); 41 } 42 43 enum oxp_board { 44 aok_zoe_a1 = 1, 45 aya_neo_air, 46 aya_neo_air_pro, 47 oxp_mini_amd, 48 oxp_mini_amd_pro, 49 }; 50 51 static enum oxp_board board; 52 53 #define OXP_SENSOR_FAN_REG 0x76 /* Fan reading is 2 registers long */ 54 #define OXP_SENSOR_PWM_ENABLE_REG 0x4A /* PWM enable is 1 register long */ 55 #define OXP_SENSOR_PWM_REG 0x4B /* PWM reading is 1 register long */ 56 57 static const struct dmi_system_id dmi_table[] = { 58 { 59 .matches = { 60 DMI_MATCH(DMI_BOARD_VENDOR, "AOKZOE"), 61 DMI_EXACT_MATCH(DMI_BOARD_NAME, "AOKZOE A1 AR07"), 62 }, 63 .driver_data = (void *) &(enum oxp_board) {aok_zoe_a1}, 64 }, 65 { 66 .matches = { 67 DMI_MATCH(DMI_BOARD_VENDOR, "AYANEO"), 68 DMI_EXACT_MATCH(DMI_BOARD_NAME, "AIR"), 69 }, 70 .driver_data = (void *) &(enum oxp_board) {aya_neo_air}, 71 }, 72 { 73 .matches = { 74 DMI_MATCH(DMI_BOARD_VENDOR, "AYANEO"), 75 DMI_EXACT_MATCH(DMI_BOARD_NAME, "AIR Pro"), 76 }, 77 .driver_data = (void *) &(enum oxp_board) {aya_neo_air_pro}, 78 }, 79 { 80 .matches = { 81 DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"), 82 DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONE XPLAYER"), 83 }, 84 .driver_data = (void *) &(enum oxp_board) {oxp_mini_amd}, 85 }, 86 { 87 .matches = { 88 DMI_MATCH(DMI_BOARD_VENDOR, "ONE-NETBOOK"), 89 DMI_EXACT_MATCH(DMI_BOARD_NAME, "ONEXPLAYER Mini Pro"), 90 }, 91 .driver_data = (void *) &(enum oxp_board) {oxp_mini_amd_pro}, 92 }, 93 {}, 94 }; 95 96 /* Helper functions to handle EC read/write */ 97 static int read_from_ec(u8 reg, int size, long *val) 98 { 99 int i; 100 int ret; 101 u8 buffer; 102 103 if (!lock_global_acpi_lock()) 104 return -EBUSY; 105 106 *val = 0; 107 for (i = 0; i < size; i++) { 108 ret = ec_read(reg + i, &buffer); 109 if (ret) 110 return ret; 111 *val <<= i * 8; 112 *val += buffer; 113 } 114 115 if (!unlock_global_acpi_lock()) 116 return -EBUSY; 117 118 return 0; 119 } 120 121 static int write_to_ec(const struct device *dev, u8 reg, u8 value) 122 { 123 int ret; 124 125 if (!lock_global_acpi_lock()) 126 return -EBUSY; 127 128 ret = ec_write(reg, value); 129 130 if (!unlock_global_acpi_lock()) 131 return -EBUSY; 132 133 return ret; 134 } 135 136 static int oxp_pwm_enable(const struct device *dev) 137 { 138 return write_to_ec(dev, OXP_SENSOR_PWM_ENABLE_REG, 0x01); 139 } 140 141 static int oxp_pwm_disable(const struct device *dev) 142 { 143 return write_to_ec(dev, OXP_SENSOR_PWM_ENABLE_REG, 0x00); 144 } 145 146 /* Callbacks for hwmon interface */ 147 static umode_t oxp_ec_hwmon_is_visible(const void *drvdata, 148 enum hwmon_sensor_types type, u32 attr, int channel) 149 { 150 switch (type) { 151 case hwmon_fan: 152 return 0444; 153 case hwmon_pwm: 154 return 0644; 155 default: 156 return 0; 157 } 158 } 159 160 static int oxp_platform_read(struct device *dev, enum hwmon_sensor_types type, 161 u32 attr, int channel, long *val) 162 { 163 int ret; 164 165 switch (type) { 166 case hwmon_fan: 167 switch (attr) { 168 case hwmon_fan_input: 169 return read_from_ec(OXP_SENSOR_FAN_REG, 2, val); 170 default: 171 break; 172 } 173 break; 174 case hwmon_pwm: 175 switch (attr) { 176 case hwmon_pwm_input: 177 ret = read_from_ec(OXP_SENSOR_PWM_REG, 1, val); 178 if (ret) 179 return ret; 180 switch (board) { 181 case aya_neo_air: 182 case aya_neo_air_pro: 183 case oxp_mini_amd: 184 *val = (*val * 255) / 100; 185 break; 186 case oxp_mini_amd_pro: 187 case aok_zoe_a1: 188 default: 189 break; 190 } 191 return 0; 192 case hwmon_pwm_enable: 193 return read_from_ec(OXP_SENSOR_PWM_ENABLE_REG, 1, val); 194 default: 195 break; 196 } 197 break; 198 default: 199 break; 200 } 201 return -EOPNOTSUPP; 202 } 203 204 static int oxp_platform_write(struct device *dev, enum hwmon_sensor_types type, 205 u32 attr, int channel, long val) 206 { 207 switch (type) { 208 case hwmon_pwm: 209 switch (attr) { 210 case hwmon_pwm_enable: 211 if (val == 1) 212 return oxp_pwm_enable(dev); 213 else if (val == 0) 214 return oxp_pwm_disable(dev); 215 return -EINVAL; 216 case hwmon_pwm_input: 217 if (val < 0 || val > 255) 218 return -EINVAL; 219 switch (board) { 220 case aya_neo_air: 221 case aya_neo_air_pro: 222 case oxp_mini_amd: 223 val = (val * 100) / 255; 224 break; 225 case aok_zoe_a1: 226 case oxp_mini_amd_pro: 227 default: 228 break; 229 } 230 return write_to_ec(dev, OXP_SENSOR_PWM_REG, val); 231 default: 232 break; 233 } 234 break; 235 default: 236 break; 237 } 238 return -EOPNOTSUPP; 239 } 240 241 /* Known sensors in the OXP EC controllers */ 242 static const struct hwmon_channel_info *oxp_platform_sensors[] = { 243 HWMON_CHANNEL_INFO(fan, 244 HWMON_F_INPUT), 245 HWMON_CHANNEL_INFO(pwm, 246 HWMON_PWM_INPUT | HWMON_PWM_ENABLE), 247 NULL, 248 }; 249 250 static const struct hwmon_ops oxp_ec_hwmon_ops = { 251 .is_visible = oxp_ec_hwmon_is_visible, 252 .read = oxp_platform_read, 253 .write = oxp_platform_write, 254 }; 255 256 static const struct hwmon_chip_info oxp_ec_chip_info = { 257 .ops = &oxp_ec_hwmon_ops, 258 .info = oxp_platform_sensors, 259 }; 260 261 /* Initialization logic */ 262 static int oxp_platform_probe(struct platform_device *pdev) 263 { 264 const struct dmi_system_id *dmi_entry; 265 struct device *dev = &pdev->dev; 266 struct device *hwdev; 267 268 /* 269 * Have to check for AMD processor here because DMI strings are the 270 * same between Intel and AMD boards, the only way to tell them apart 271 * is the CPU. 272 * Intel boards seem to have different EC registers and values to 273 * read/write. 274 */ 275 dmi_entry = dmi_first_match(dmi_table); 276 if (!dmi_entry || boot_cpu_data.x86_vendor != X86_VENDOR_AMD) 277 return -ENODEV; 278 279 board = *((enum oxp_board *) dmi_entry->driver_data); 280 281 hwdev = devm_hwmon_device_register_with_info(dev, "oxpec", NULL, 282 &oxp_ec_chip_info, NULL); 283 284 return PTR_ERR_OR_ZERO(hwdev); 285 } 286 287 static struct platform_driver oxp_platform_driver = { 288 .driver = { 289 .name = "oxp-platform", 290 }, 291 .probe = oxp_platform_probe, 292 }; 293 294 static struct platform_device *oxp_platform_device; 295 296 static int __init oxp_platform_init(void) 297 { 298 oxp_platform_device = 299 platform_create_bundle(&oxp_platform_driver, 300 oxp_platform_probe, NULL, 0, NULL, 0); 301 302 return PTR_ERR_OR_ZERO(oxp_platform_device); 303 } 304 305 static void __exit oxp_platform_exit(void) 306 { 307 platform_device_unregister(oxp_platform_device); 308 platform_driver_unregister(&oxp_platform_driver); 309 } 310 311 MODULE_DEVICE_TABLE(dmi, dmi_table); 312 313 module_init(oxp_platform_init); 314 module_exit(oxp_platform_exit); 315 316 MODULE_AUTHOR("Joaquín Ignacio Aramendía <samsagax@gmail.com>"); 317 MODULE_DESCRIPTION("Platform driver that handles EC sensors of OneXPlayer devices"); 318 MODULE_LICENSE("GPL"); 319