[2/3] hwmon: Driver for OMAP3 temperature sensor

Message ID	1419597294-21487-3-git-send-email-sre@kernel.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Sebastian Reichel <sre@kernel.org> To: Sebastian Reichel <sre@kernel.org>, Pavel Machek <pavel@ucw.cz>, Pali Rohar <pali.rohar@gmail.com>, Jean Delvare <jdelvare@suse.de>, Guenter Roeck <linux@roeck-us.net>, Tony Lindgren <tony@atomide.com>, =?UTF-8?q?Beno=C3=AEt=20Cousson?= <bcousson@baylibre.com> Subject: [PATCH 2/3] hwmon: Driver for OMAP3 temperature sensor Date: Fri, 26 Dec 2014 13:34:53 +0100 Message-Id: <1419597294-21487-3-git-send-email-sre@kernel.org> In-Reply-To: <1419597294-21487-1-git-send-email-sre@kernel.org> References: <20141226102933.GA28778@amd> <1419597294-21487-1-git-send-email-sre@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com>, devicetree@vger.kernel.org, Pawel Moll <pawel.moll@arm.com>, Ian Campbell <ijc+devicetree@hellion.org.uk>, linux-kernel@vger.kernel.org, lm-sensors@lm-sensors.org, Rob Herring <robh+dt@kernel.org>, Kumar Gala <galak@codeaurora.org>, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 6529c09..749748d 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1135,6 +1135,14 @@ config SENSORS_NCT7802 This driver can also be built as a module. If so, the module will be called nct7802. +config SENSORS_OMAP3_TEMP + tristate "OMAP3 Temperature Sensor" + depends on OF && (ARCH_OMAP3 || COMPILE_TEST) + select MFD_SYSCON + help + If you say yes here you get support for the temperature sensor + built into OMAP3 processors. + config SENSORS_PCF8591 tristate "Philips PCF8591 ADC/DAC" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 6728064..5a69773 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -120,6 +120,7 @@ obj-$(CONFIG_SENSORS_NCT6683) += nct6683.o obj-$(CONFIG_SENSORS_NCT6775) += nct6775.o obj-$(CONFIG_SENSORS_NCT7802) += nct7802.o obj-$(CONFIG_SENSORS_NTC_THERMISTOR) += ntc_thermistor.o +obj-$(CONFIG_SENSORS_OMAP3_TEMP) += omap3-temp.o obj-$(CONFIG_SENSORS_PC87360) += pc87360.o obj-$(CONFIG_SENSORS_PC87427) += pc87427.o obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o diff --git a/drivers/hwmon/omap3-temp.c b/drivers/hwmon/omap3-temp.c new file mode 100644 index 0000000..5c331c5 --- /dev/null +++ b/drivers/hwmon/omap3-temp.c @@ -0,0 +1,307 @@ +/* + * omap3-temp.c - driver for OMAP34xx and OMAP36xx temperature sensor + * + * Copyright (c) 2014 Sebastian Reichel <sre@kernel.org> + * Copyright (C) 2008, 2009, 2010 Nokia Corporation + * + * based on Peter De Schrijver's driver for N9 + * + * 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 <linux/clk.h> +#include <linux/hrtimer.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/sched.h> +#include <linux/stat.h> + +/* 32.768Khz clock speed in nano seconds */ +#define CLOCK_32K_SPEED_NS 30518 + +/* minimum delay for EOCZ rise after SOC rise is + * 11 cycles of the 32.768Khz clock */ +#define EOCZ_MIN_RISING_DELAY (11 * CLOCK_32K_SPEED_NS) + +/* From docs, maximum delay for EOCZ rise after SOC rise is + * 14 cycles of the 32.768Khz clock. But after some experiments, + * 24 cycles as maximum is safer. */ +#define EOCZ_MAX_RISING_DELAY (24 * CLOCK_32K_SPEED_NS) + +/* minimum delay for EOCZ falling is + * 36 cycles of the 32.768Khz clock */ +#define EOCZ_MIN_FALLING_DELAY (36 * CLOCK_32K_SPEED_NS) + +/* maximum delay for EOCZ falling is + * 40 cycles of the 32.768Khz clock */ +#define EOCZ_MAX_FALLING_DELAY (40 * CLOCK_32K_SPEED_NS) + +/* temperature register offset in the syscon register area */ +#define SYSCON_TEMP_REG 0x02B4 + +/* TRM: Table 7-11. ADC Codes Versus Temperature */ +static const int adc_to_temp_3430[] = { + -400, -400, -400, -400, -400, -390, -380, -360, -340, -320, -310, + -290, -280, -260, -250, -240, -220, -210, -190, -180, -170, -150, + -140, -120, -110, -90, -80, -70, -50, -40, -20, -10, 00, 10, 30, + 40, 50, 70, 80, 100, 110, 130, 140, 150, 170, 180, 200, 210, 220, + 240, 250, 270, 280, 300, 310, 320, 340, 350, 370, 380, 390, 410, 420, + 440, 450, 470, 480, 490, 510, 520, 530, 550, 560, 580, 590, 600, 620, + 630, 650, 660, 670, 690, 700, 720, 730, 740, 760, 770, 790, 800, 810, + 830, 840, 850, 870, 880, 890, 910, 920, 940, 950, 960, 980, 990, 1000, + 1020, 1030, 1050, 1060, 1070, 1090, 1100, 1110, 1130, 1140, 1160, + 1170, 1180, 1200, 1210, 1220, 1240, 1240, 1250, 1250, 1250, 1250, + 1250}; + +/* TRM: Table 13-11. ADC Code Versus Temperature */ +static const int adc_to_temp_3630[] = { + -400, -400, -400, -400, -400, -400, -400, -400, -400, -400, -400, + -400, -400, -400, -380, -350, -340, -320, -300, -280, -260, -240, + -220, -200, -185, -170, -150, -135, -120, -100, -80, -65, -50, -35, + -15, 0, 20, 35, 50, 65, 85, 100, 120, 135, 150, 170, 190, 210, 230, + 250, 270, 285, 300, 320, 335, 350, 370, 385, 400, 420, 435, 450, 470, + 485, 500, 520, 535, 550, 570, 585, 600, 620, 640, 660, 680, 700, 715, + 735, 750, 770, 785, 800, 820, 835, 850, 870, 885, 900, 920, 935, 950, + 970, 985, 1000, 1020, 1035, 1050, 1070, 1090, 1110, 1130, 1150, 1170, + 1185, 1200, 1220, 1235, 1250, 1250, 1250, 1250, 1250, 1250, 1250, + 1250, 1250, 1250, 1250, 1250, 1250, 1250, 1250, 1250, 1250, 1250, + 1250, 1250, 1250}; + +struct omap3_temp_type { + const int *adc_to_temp; + u8 soc_bit; + u8 eocz_bit; +}; + +/* TRM: Table 7-228. CONTROL_TEMP_SENSOR */ +static const struct omap3_temp_type omap34xx_temp_type = { + .eocz_bit = 7, + .soc_bit = 8, + .adc_to_temp = adc_to_temp_3430, +}; + +/* TRM: Table 13-239. CONTROL_TEMP_SENSOR */ +static const struct omap3_temp_type omap36xx_temp_type = { + .eocz_bit = 8, + .soc_bit = 9, + .adc_to_temp = adc_to_temp_3630, +}; + +struct omap3_temp_data { + struct device *hwmon_dev; + struct regmap *syscon; + struct clk *clk_32k; + struct omap3_temp_type *hwdata; + /* mutex to protect the update procedure while reading from sensor */ + struct mutex update_lock; + const char *name; + unsigned long last_updated; + u32 temperature; + bool valid; +}; + +static inline u32 wait_for_eocz(int min_delay, int max_delay, u32 level, + struct omap3_temp_data *data) +{ + ktime_t timeout, expire; + u32 temp_sensor_reg, eocz_mask; + + eocz_mask = BIT(data->hwdata->eocz_bit); + level &= 1; + level *= eocz_mask; + + expire = ktime_add_ns(ktime_get(), max_delay); + timeout = ktime_set(0, min_delay); + __set_current_state(TASK_INTERRUPTIBLE); + schedule_hrtimeout(&timeout, HRTIMER_MODE_REL); + do { + regmap_read(data->syscon, SYSCON_TEMP_REG, &temp_sensor_reg); + if ((temp_sensor_reg & eocz_mask) == level) + break; + } while (ktime_us_delta(expire, ktime_get()) > 0); + + return (temp_sensor_reg & eocz_mask) == level; +} + +static int omap3_temp_update(struct omap3_temp_data *data) +{ + int e = 0; + u32 temp_sensor_reg; + u32 soc_mask = BIT(data->hwdata->soc_bit); + + mutex_lock(&data->update_lock); + + if (!data->valid || time_after(jiffies, data->last_updated + HZ)) { + clk_enable(data->clk_32k); + + regmap_update_bits(data->syscon, SYSCON_TEMP_REG, + soc_mask, soc_mask); + + if (!wait_for_eocz(EOCZ_MIN_RISING_DELAY, + EOCZ_MAX_RISING_DELAY, 1, data)) { + e = -EIO; + goto err; + } + + regmap_update_bits(data->syscon, SYSCON_TEMP_REG, soc_mask, 0); + + if (!wait_for_eocz(EOCZ_MIN_FALLING_DELAY, + EOCZ_MAX_FALLING_DELAY, 0, data)) { + e = -EIO; + goto err; + } + + regmap_read(data->syscon, SYSCON_TEMP_REG, &temp_sensor_reg); + data->temperature = temp_sensor_reg & ((1<<7) - 1); + data->last_updated = jiffies; + data->valid = true; + +err: + clk_disable(data->clk_32k); + } + + mutex_unlock(&data->update_lock); + return e; +} + +static ssize_t show_temp(struct device *dev, + struct device_attribute *devattr, char *buf) +{ + struct omap3_temp_data *data = dev_get_drvdata(dev); + int temp; + int ret; + + ret = omap3_temp_update(data); + if (ret < 0) + return ret; + + temp = data->hwdata->adc_to_temp[data->temperature]; + + return sprintf(buf, "%d.%d\n", temp / 10, temp % 10); +} + +static ssize_t show_name(struct device *dev, + struct device_attribute *devattr, char *buf) +{ + struct omap3_temp_data *data = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", data->name); +} + +static SENSOR_DEVICE_ATTR_2(temp_input, S_IRUGO, show_temp, NULL, 0, 0); +static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); + +static const struct of_device_id omap3_temp_dt_ids[] = { + { + .compatible = "ti,omap34xx-temperature-sensor", + .data = &omap34xx_temp_type, + }, + { + .compatible = "ti,omap36xx-temperature-sensor", + .data = &omap36xx_temp_type, + }, + { } +}; +MODULE_DEVICE_TABLE(of, omap3_temp_dt_ids); + +static int omap3_temp_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct omap3_temp_data *data; + const struct of_device_id *of_id; + int err; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + of_id = of_match_device(omap3_temp_dt_ids, &pdev->dev); + if (!of_id) { + dev_warn(&pdev->dev, "unsupported device!"); + return -ENODEV; + } + + mutex_init(&data->update_lock); + data->name = "omap3-temperature"; + + data->clk_32k = devm_clk_get(&pdev->dev, "fck"); + if (IS_ERR(data->clk_32k)) + return PTR_ERR(data->clk_32k); + + data->hwdata = (struct omap3_temp_type *)of_id->data; + + data->syscon = syscon_regmap_lookup_by_phandle(np, "syscon"); + if (IS_ERR(data->syscon)) + return PTR_ERR(data->syscon); + + platform_set_drvdata(pdev, data); + + err = device_create_file(&pdev->dev, + &sensor_dev_attr_temp_input.dev_attr); + if (err) + goto fail_temp_file; + + err = device_create_file(&pdev->dev, &dev_attr_name); + if (err) + goto fail_name_file; + + data->hwmon_dev = hwmon_device_register(&pdev->dev); + if (IS_ERR(data->hwmon_dev)) { + err = PTR_ERR(data->hwmon_dev); + goto fail_hwmon_reg; + } + + return 0; + +fail_hwmon_reg: + device_remove_file(&pdev->dev, &dev_attr_name); +fail_name_file: + device_remove_file(&pdev->dev, &sensor_dev_attr_temp_input.dev_attr); +fail_temp_file: + return err; +} + +static int omap3_temp_remove(struct platform_device *pdev) +{ + struct omap3_temp_data *data = platform_get_drvdata(pdev); + + if (!data) + return 0; + + hwmon_device_unregister(data->hwmon_dev); + device_remove_file(&pdev->dev, &dev_attr_name); + device_remove_file(&pdev->dev, &sensor_dev_attr_temp_input.dev_attr); + + return 0; +} + +static struct platform_driver omap3_temp_driver = { + .probe = omap3_temp_probe, + .remove = omap3_temp_remove, + .driver = { + .name = "omap3-temperature", + .of_match_table = omap3_temp_dt_ids, + }, +}; + +module_platform_driver(omap3_temp_driver); + +MODULE_AUTHOR("Sebastian Reichel"); +MODULE_DESCRIPTION("OMAP34xx/OMAP36xx temperature sensor"); +MODULE_LICENSE("GPL");

[2/3] hwmon: Driver for OMAP3 temperature sensor

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