/* * omap34xx_temp.c - Linux kernel module for OMAP34xx hardware monitoring * * Copyright (C) 2008 Nokia Corporation * * Written by Peter De Schrijver * * Inspired by k8temp.c * * This file is subject to the terms and conditions of the GNU General * Public License. See the file "COPYING" in the main directory of this * archive for more details. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include #include #include #include #include #include #include #define TEMP_SENSOR_SOC BIT(8) #define TEMP_SENSOR_EOCZ BIT(7) /* minimum delay for EOCZ rise after SOC rise is * 11 cycles of the 32.768Khz clock */ #define EOCZ_MIN_RISING_DELAY (11 * 30518) /* maximum delay for EOCZ rise after SOC rise is * 14 cycles of the 32.768Khz clock */ #define EOCZ_MAX_RISING_DELAY (14 * 30518) /* minimum delay for EOCZ falling is * 36 cycles of the 32.768Khz clock */ #define EOCZ_MIN_FALLING_DELAY (36 * 30518) /* maximum delay for EOCZ falling is * 40 cycles of the 32.768Khz clock */ #define EOCZ_MAX_FALLING_DELAY (40 * 30518) struct omap34xx_data { struct device *hwmon_dev; struct clk *clk_32k; struct mutex update_lock; const char *name; char valid; unsigned long last_updated; u32 temp; }; static struct platform_device omap34xx_temp_device = { .name = "omap34xx_temp", .id = -1, }; static int adc_to_temp[] = { -40, -40, -40, -40, -40, -39, -38, -36, -34, -32, -31, -29, -28, -26, -25, -24, -22, -21, -19, -18, -17, -15, -14, -12, -11, -9, -8, -7, -5, -4, -2, -1, 0, 1, 3, 4, 5, 7, 8, 10, 11, 13, 14, 15, 17, 18, 20, 21, 22, 24, 25, 27, 28, 30, 31, 32, 34, 35, 37, 38, 39, 41, 42, 44, 45, 47, 48, 49, 51, 52, 53, 55, 56, 58, 59, 60, 62, 63, 65, 66, 67, 69, 70, 72, 73, 74, 76, 77, 79, 80, 81, 83, 84, 85, 87, 88, 89, 91, 92, 94, 95, 96, 98, 99, 100, 102, 103, 105, 106, 107, 109, 110, 111, 113, 114, 116, 117, 118, 120, 121, 122, 124, 124, 125, 125, 125, 125, 125}; static inline u32 wait_for_eocz(int min_delay, int max_delay, u32 level) { struct timespec timeout; ktime_t expire; u32 temp_sensor_reg; level &= 1; level *= TEMP_SENSOR_EOCZ; expire = ktime_add_ns(ktime_get(), max_delay); timeout = ns_to_timespec(min_delay); hrtimer_nanosleep(&timeout, NULL, HRTIMER_MODE_REL, CLOCK_MONOTONIC); do { temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR); if ((temp_sensor_reg & TEMP_SENSOR_EOCZ) == level) break; } while (ktime_us_delta(expire, ktime_get()) > 0); return (temp_sensor_reg & TEMP_SENSOR_EOCZ) == level; } static void omap34xx_update(struct omap34xx_data *data) { u32 temp_sensor_reg; mutex_lock(&data->update_lock); if (!data->valid || time_after(jiffies, data->last_updated + HZ)) { clk_enable(data->clk_32k); temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR); temp_sensor_reg |= TEMP_SENSOR_SOC; omap_ctrl_writel(temp_sensor_reg, OMAP343X_CONTROL_TEMP_SENSOR); if (!wait_for_eocz(EOCZ_MIN_RISING_DELAY, EOCZ_MAX_RISING_DELAY, 1)) goto err; temp_sensor_reg = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR); temp_sensor_reg &= ~TEMP_SENSOR_SOC; omap_ctrl_writel(temp_sensor_reg, OMAP343X_CONTROL_TEMP_SENSOR); if (!wait_for_eocz(EOCZ_MIN_FALLING_DELAY, EOCZ_MAX_FALLING_DELAY, 0)) goto err; data->temp = omap_ctrl_readl(OMAP343X_CONTROL_TEMP_SENSOR) & ((1<<7) - 1); data->last_updated = jiffies; data->valid = 1; err: clk_disable(data->clk_32k); } mutex_unlock(&data->update_lock); } static ssize_t show_name(struct device *dev, struct device_attribute *devattr, char *buf) { struct omap34xx_data *data = dev_get_drvdata(dev); return sprintf(buf, "%s\n", data->name); } static ssize_t show_temp_raw(struct device *dev, struct device_attribute *devattr, char *buf) { struct omap34xx_data *data = dev_get_drvdata(dev); omap34xx_update(data); return sprintf(buf, "%d\n", data->temp); } static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, char *buf) { struct omap34xx_data *data = dev_get_drvdata(dev); omap34xx_update(data); return sprintf(buf, "%d\n", adc_to_temp[data->temp]); } static SENSOR_DEVICE_ATTR_2(temp1_input, S_IRUGO, show_temp, NULL, 0, 0); static SENSOR_DEVICE_ATTR_2(temp1_input_raw, S_IRUGO, show_temp_raw, NULL, 0, 0); static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); static int __devinit omap34xx_temp_probe(void) { int err; struct omap34xx_data *data; err = platform_device_register(&omap34xx_temp_device); if (err) { printk(KERN_ERR "Unable to register omap34xx temperature device\n"); goto exit; } data = kzalloc(sizeof(struct omap34xx_data), GFP_KERNEL); if (!data) { err = -ENOMEM; goto exit_platform; } dev_set_drvdata(&omap34xx_temp_device.dev, data); mutex_init(&data->update_lock); data->name = "omap34xx_temp"; data->clk_32k = clk_get(&omap34xx_temp_device.dev, "ts_fck"); if (IS_ERR(data->clk_32k)) { err = PTR_ERR(data->clk_32k); goto exit_free; } err = device_create_file(&omap34xx_temp_device.dev, &sensor_dev_attr_temp1_input.dev_attr); if (err) goto clock_free; err = device_create_file(&omap34xx_temp_device.dev, &sensor_dev_attr_temp1_input_raw.dev_attr); if (err) goto exit_remove; err = device_create_file(&omap34xx_temp_device.dev, &dev_attr_name); if (err) goto exit_remove_raw; data->hwmon_dev = hwmon_device_register(&omap34xx_temp_device.dev); if (IS_ERR(data->hwmon_dev)) { err = PTR_ERR(data->hwmon_dev); goto exit_remove_all; } return 0; exit_remove_all: device_remove_file(&omap34xx_temp_device.dev, &dev_attr_name); exit_remove_raw: device_remove_file(&omap34xx_temp_device.dev, &sensor_dev_attr_temp1_input_raw.dev_attr); exit_remove: device_remove_file(&omap34xx_temp_device.dev, &sensor_dev_attr_temp1_input.dev_attr); clock_free: clk_put(data->clk_32k); exit_free: kfree(data); exit_platform: platform_device_unregister(&omap34xx_temp_device); exit: return err; } static int __init omap34xx_temp_init(void) { return omap34xx_temp_probe(); } static void __exit omap34xx_temp_exit(void) { struct omap34xx_data *data = dev_get_drvdata(&omap34xx_temp_device.dev); clk_put(data->clk_32k); hwmon_device_unregister(data->hwmon_dev); device_remove_file(&omap34xx_temp_device.dev, &sensor_dev_attr_temp1_input.dev_attr); device_remove_file(&omap34xx_temp_device.dev, &dev_attr_name); kfree(data); platform_device_unregister(&omap34xx_temp_device); } MODULE_AUTHOR("Peter De Schrijver"); MODULE_DESCRIPTION("Omap34xx temperature sensor"); MODULE_LICENSE("GPL"); module_init(omap34xx_temp_init) module_exit(omap34xx_temp_exit)