X-Git-Url: http://www.pilppa.org/gitweb/gitweb.cgi?p=linux-2.6-omap-h63xx.git;a=blobdiff_plain;f=drivers%2Fhwmon%2Fomap34xx_temp.c;fp=drivers%2Fhwmon%2Fomap34xx_temp.c;h=18e07643165fef430b7631ad053a9011b44efb5f;hp=0000000000000000000000000000000000000000;hb=b934c987ee1764eb09b8843a3ee00eabc24bd52c;hpb=14fc69723d3442ef46f8f82b3f481e82f06a346d diff --git a/drivers/hwmon/omap34xx_temp.c b/drivers/hwmon/omap34xx_temp.c new file mode 100644 index 00000000000..18e07643165 --- /dev/null +++ b/drivers/hwmon/omap34xx_temp.c @@ -0,0 +1,268 @@ +/* + * 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) +