--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Emil Renner Berthing <kernel@esmil.dk>
+ * Copyright (C) 2021 Samin Guo <samin.guo@starfivetech.com>
+ */
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/hwmon.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+/*
+ * TempSensor reset. The RSTN can be de-asserted once the analog core has
+ * powered up. Trst(min 100ns)
+ * 0:reset 1:de-assert
+ */
+#define SFCTEMP_RSTN BIT(0)
+
+/*
+ * TempSensor analog core power down. The analog core will be powered up
+ * Tpu(min 50us) after PD is de-asserted. RSTN should be held low until the
+ * analog core is powered up.
+ * 0:power up 1:power down
+ */
+#define SFCTEMP_PD BIT(1)
+
+/*
+ * TempSensor start conversion enable.
+ * 0:disable 1:enable
+ */
+#define SFCTEMP_RUN BIT(2)
+
+/*
+ * TempSensor conversion value output.
+ * Temp(C)=DOUT*Y/4094 - K
+ */
+#define SFCTEMP_DOUT_POS 16
+#define SFCTEMP_DOUT_MSK GENMASK(27, 16)
+
+/* DOUT to Celcius conversion constants */
+#define SFCTEMP_Y1000 237500L
+#define SFCTEMP_Z 4094L
+#define SFCTEMP_K1000 81100L
+
+struct sfctemp {
+ /* serialize access to hardware register and enabled below */
+ struct mutex lock;
+ struct completion conversion_done;
+ void __iomem *regs;
+ struct clk *clk_sense;
+ struct clk *clk_bus;
+ struct reset_control *rst_sense;
+ struct reset_control *rst_bus;
+ bool enabled;
+};
+
+static irqreturn_t sfctemp_isr(int irq, void *data)
+{
+ struct sfctemp *sfctemp = data;
+
+ complete(&sfctemp->conversion_done);
+ return IRQ_HANDLED;
+}
+
+static void sfctemp_power_up(struct sfctemp *sfctemp)
+{
+ /* make sure we're powered down first */
+ writel(SFCTEMP_PD, sfctemp->regs);
+ udelay(1);
+
+ writel(0, sfctemp->regs);
+ /* wait t_pu(50us) + t_rst(100ns) */
+ usleep_range(60, 200);
+
+ /* de-assert reset */
+ writel(SFCTEMP_RSTN, sfctemp->regs);
+ udelay(1); /* wait t_su(500ps) */
+}
+
+static void sfctemp_power_down(struct sfctemp *sfctemp)
+{
+ writel(SFCTEMP_PD, sfctemp->regs);
+}
+
+static void sfctemp_run_single(struct sfctemp *sfctemp)
+{
+ writel(SFCTEMP_RSTN | SFCTEMP_RUN, sfctemp->regs);
+ udelay(1);
+ writel(SFCTEMP_RSTN, sfctemp->regs);
+}
+
+static int sfctemp_enable(struct sfctemp *sfctemp)
+{
+ int ret = 0;
+
+ mutex_lock(&sfctemp->lock);
+ if (sfctemp->enabled)
+ goto done;
+
+ ret = clk_prepare_enable(sfctemp->clk_bus);
+ if (ret)
+ goto err;
+ ret = reset_control_deassert(sfctemp->rst_bus);
+ if (ret)
+ goto err_disable_bus;
+
+ ret = clk_prepare_enable(sfctemp->clk_sense);
+ if (ret)
+ goto err_assert_bus;
+ ret = reset_control_deassert(sfctemp->rst_sense);
+ if (ret)
+ goto err_disable_sense;
+
+ sfctemp_power_up(sfctemp);
+ sfctemp->enabled = true;
+done:
+ mutex_unlock(&sfctemp->lock);
+ return ret;
+
+err_disable_sense:
+ clk_disable_unprepare(sfctemp->clk_sense);
+err_assert_bus:
+ reset_control_assert(sfctemp->rst_bus);
+err_disable_bus:
+ clk_disable_unprepare(sfctemp->clk_bus);
+err:
+ mutex_unlock(&sfctemp->lock);
+ return ret;
+}
+
+static int sfctemp_disable(struct sfctemp *sfctemp)
+{
+ mutex_lock(&sfctemp->lock);
+ if (!sfctemp->enabled)
+ goto done;
+
+ sfctemp_power_down(sfctemp);
+ reset_control_assert(sfctemp->rst_sense);
+ clk_disable_unprepare(sfctemp->clk_sense);
+ reset_control_assert(sfctemp->rst_bus);
+ clk_disable_unprepare(sfctemp->clk_bus);
+ sfctemp->enabled = false;
+done:
+ mutex_unlock(&sfctemp->lock);
+ return 0;
+}
+
+static void sfctemp_disable_action(void *data)
+{
+ sfctemp_disable(data);
+}
+
+static int sfctemp_convert(struct sfctemp *sfctemp, long *val)
+{
+ int ret;
+
+ mutex_lock(&sfctemp->lock);
+ if (!sfctemp->enabled) {
+ ret = -ENODATA;
+ goto out;
+ }
+
+ sfctemp_run_single(sfctemp);
+
+ ret = wait_for_completion_interruptible_timeout(&sfctemp->conversion_done,
+ msecs_to_jiffies(10));
+ if (ret <= 0) {
+ if (ret == 0)
+ ret = -ETIMEDOUT;
+ goto out;
+ }
+
+ /* calculate temperature in milli Celcius */
+ *val = (long)((readl(sfctemp->regs) & SFCTEMP_DOUT_MSK) >> SFCTEMP_DOUT_POS)
+ * SFCTEMP_Y1000 / SFCTEMP_Z - SFCTEMP_K1000;
+
+ ret = 0;
+out:
+ mutex_unlock(&sfctemp->lock);
+ return ret;
+}
+
+static umode_t sfctemp_is_visible(const void *data, enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_enable:
+ return 0644;
+ case hwmon_temp_input:
+ return 0444;
+ }
+ return 0;
+ default:
+ return 0;
+ }
+}
+
+static int sfctemp_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct sfctemp *sfctemp = dev_get_drvdata(dev);
+
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_enable:
+ *val = sfctemp->enabled;
+ return 0;
+ case hwmon_temp_input:
+ return sfctemp_convert(sfctemp, val);
+ }
+ return -EINVAL;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int sfctemp_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ struct sfctemp *sfctemp = dev_get_drvdata(dev);
+
+ switch (type) {
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_enable:
+ if (val == 0)
+ return sfctemp_disable(sfctemp);
+ if (val == 1)
+ return sfctemp_enable(sfctemp);
+ break;
+ }
+ return -EINVAL;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct hwmon_channel_info *sfctemp_info[] = {
+ HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
+ HWMON_CHANNEL_INFO(temp, HWMON_T_ENABLE | HWMON_T_INPUT),
+ NULL
+};
+
+static const struct hwmon_ops sfctemp_hwmon_ops = {
+ .is_visible = sfctemp_is_visible,
+ .read = sfctemp_read,
+ .write = sfctemp_write,
+};
+
+static const struct hwmon_chip_info sfctemp_chip_info = {
+ .ops = &sfctemp_hwmon_ops,
+ .info = sfctemp_info,
+};
+
+static int sfctemp_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device *hwmon_dev;
+ struct sfctemp *sfctemp;
+ int ret;
+
+ sfctemp = devm_kzalloc(dev, sizeof(*sfctemp), GFP_KERNEL);
+ if (!sfctemp)
+ return -ENOMEM;
+
+ dev_set_drvdata(dev, sfctemp);
+ mutex_init(&sfctemp->lock);
+ init_completion(&sfctemp->conversion_done);
+
+ sfctemp->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(sfctemp->regs))
+ return PTR_ERR(sfctemp->regs);
+
+ sfctemp->clk_sense = devm_clk_get(dev, "sense");
+ if (IS_ERR(sfctemp->clk_sense))
+ return dev_err_probe(dev, PTR_ERR(sfctemp->clk_sense),
+ "error getting sense clock\n");
+
+ sfctemp->clk_bus = devm_clk_get(dev, "bus");
+ if (IS_ERR(sfctemp->clk_bus))
+ return dev_err_probe(dev, PTR_ERR(sfctemp->clk_bus),
+ "error getting bus clock\n");
+
+ sfctemp->rst_sense = devm_reset_control_get_exclusive(dev, "sense");
+ if (IS_ERR(sfctemp->rst_sense))
+ return dev_err_probe(dev, PTR_ERR(sfctemp->rst_sense),
+ "error getting sense reset\n");
+
+ sfctemp->rst_bus = devm_reset_control_get_exclusive(dev, "bus");
+ if (IS_ERR(sfctemp->rst_bus))
+ return dev_err_probe(dev, PTR_ERR(sfctemp->rst_bus),
+ "error getting busreset\n");
+
+ ret = reset_control_assert(sfctemp->rst_sense);
+ if (ret)
+ return dev_err_probe(dev, ret, "error asserting sense reset\n");
+
+ ret = reset_control_assert(sfctemp->rst_bus);
+ if (ret)
+ return dev_err_probe(dev, ret, "error asserting bus reset\n");
+
+ ret = platform_get_irq(pdev, 0);
+ if (ret < 0)
+ return ret;
+
+ ret = devm_request_irq(dev, ret, sfctemp_isr, 0, pdev->name, sfctemp);
+ if (ret)
+ return dev_err_probe(dev, ret, "error requesting irq\n");
+
+ ret = devm_add_action(dev, sfctemp_disable_action, sfctemp);
+ if (ret)
+ return ret;
+
+ ret = sfctemp_enable(sfctemp);
+ if (ret)
+ return dev_err_probe(dev, ret, "error enabling temperature sensor: %d\n", ret);
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev, pdev->name, sfctemp,
+ &sfctemp_chip_info, NULL);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct of_device_id sfctemp_of_match[] = {
+ { .compatible = "starfive,jh7100-temp" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sfctemp_of_match);
+
+static struct platform_driver sfctemp_driver = {
+ .probe = sfctemp_probe,
+ .driver = {
+ .name = "sfctemp",
+ .of_match_table = sfctemp_of_match,
+ },
+};
+module_platform_driver(sfctemp_driver);
+
+MODULE_AUTHOR("Emil Renner Berthing");
+MODULE_DESCRIPTION("StarFive JH7100 temperature sensor driver");
+MODULE_LICENSE("GPL");
projects / platform / kernel / linux-starfive.git / commitdiff