Add driver for cros-ec-regulator, representing a voltage regulator that
is connected and controlled by ChromeOS EC, and is controlled by kernel
with EC host commands.
Signed-off-by: Pi-Hsun Shih <[email protected]>
---
This patch contains function cros_ec_cmd that is copied from the series:
https://lore.kernel.org/patchwork/project/lkml/list/?series=428457.
I can't find the first patch in that v2 series, so the function is
modified from v1 of that series according to reviewers comment:
https://lore.kernel.org/patchwork/patch/1188110/
I copied the function instead of depending on that series since I feel
the function is small enough, and the series has stalled for some time.
---
drivers/regulator/Kconfig | 7 +
drivers/regulator/Makefile | 1 +
drivers/regulator/cros-ec-regulator.c | 261 ++++++++++++++++++
.../linux/platform_data/cros_ec_commands.h | 82 ++++++
4 files changed, 351 insertions(+)
create mode 100644 drivers/regulator/cros-ec-regulator.c
diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig
index 8f677f5d79b4..3543e0fc54ca 100644
--- a/drivers/regulator/Kconfig
+++ b/drivers/regulator/Kconfig
@@ -238,6 +238,13 @@ config REGULATOR_CPCAP
Say y here for CPCAP regulator found on some Motorola phones
and tablets such as Droid 4.
+config REGULATOR_CROS_EC
+ tristate "ChromeOS EC regulators"
+ depends on CROS_EC
+ help
+ This driver supports voltage regulators that is connected to ChromeOS
+ EC and controlled through EC host commands.
+
config REGULATOR_DA903X
tristate "Dialog Semiconductor DA9030/DA9034 regulators"
depends on PMIC_DA903X
diff --git a/drivers/regulator/Makefile b/drivers/regulator/Makefile
index e8f163371071..46592c160d22 100644
--- a/drivers/regulator/Makefile
+++ b/drivers/regulator/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_REGULATOR_USERSPACE_CONSUMER) += userspace-consumer.o
obj-$(CONFIG_REGULATOR_88PG86X) += 88pg86x.o
obj-$(CONFIG_REGULATOR_88PM800) += 88pm800-regulator.o
obj-$(CONFIG_REGULATOR_88PM8607) += 88pm8607.o
+obj-$(CONFIG_REGULATOR_CROS_EC) += cros-ec-regulator.o
obj-$(CONFIG_REGULATOR_CPCAP) += cpcap-regulator.o
obj-$(CONFIG_REGULATOR_AAT2870) += aat2870-regulator.o
obj-$(CONFIG_REGULATOR_AB3100) += ab3100.o
diff --git a/drivers/regulator/cros-ec-regulator.c b/drivers/regulator/cros-ec-regulator.c
new file mode 100644
index 000000000000..495006f6381c
--- /dev/null
+++ b/drivers/regulator/cros-ec-regulator.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright 2020 Google LLC.
+
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_data/cros_ec_proto.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include <linux/regulator/of_regulator.h>
+#include <linux/slab.h>
+
+struct cros_ec_regulator_data {
+ struct regulator_desc desc;
+ struct regulator_dev *dev;
+ struct cros_ec_device *ec_dev;
+
+ u32 index;
+
+ u16 *voltages_mV;
+ u16 num_voltages;
+};
+
+static int cros_ec_cmd(struct cros_ec_device *ec, u32 version, u32 command,
+ void *outdata, u32 outsize, void *indata, u32 insize)
+{
+ struct cros_ec_command *msg;
+ int ret;
+
+ msg = kzalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ msg->version = version;
+ msg->command = command;
+ msg->outsize = outsize;
+ msg->insize = insize;
+
+ if (outdata && outsize > 0)
+ memcpy(msg->data, outdata, outsize);
+
+ ret = cros_ec_cmd_xfer_status(ec, msg);
+ if (ret < 0) {
+ dev_warn(ec->dev, "Command failed: %d\n", msg->result);
+ goto cleanup;
+ }
+
+ if (insize)
+ memcpy(indata, msg->data, insize);
+
+cleanup:
+ kfree(msg);
+ return ret;
+}
+
+static int cros_ec_regulator_set_state(struct regulator_dev *dev, bool enable)
+{
+ struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+ struct ec_params_regulator_enable cmd = {
+ .index = data->index,
+ .enable = enable ? 1 : 0,
+ };
+
+ return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_ENABLE, &cmd,
+ sizeof(cmd), NULL, 0);
+}
+
+static int cros_ec_regulator_enable(struct regulator_dev *dev)
+{
+ return cros_ec_regulator_set_state(dev, true);
+}
+
+static int cros_ec_regulator_disable(struct regulator_dev *dev)
+{
+ return cros_ec_regulator_set_state(dev, false);
+}
+
+static int cros_ec_regulator_is_enabled(struct regulator_dev *dev)
+{
+ struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+ struct ec_params_regulator_is_enabled cmd = {
+ .index = data->index,
+ };
+ struct ec_response_regulator_is_enabled resp;
+ int ret;
+
+ ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_IS_ENABLED, &cmd,
+ sizeof(cmd), &resp, sizeof(resp));
+ if (ret < 0)
+ return ret;
+ return resp.enabled;
+}
+
+static int cros_ec_regulator_list_voltage(struct regulator_dev *dev,
+ unsigned int selector)
+{
+ struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+
+ if (selector >= data->num_voltages)
+ return -EINVAL;
+
+ return data->voltages_mV[selector] * 1000;
+}
+
+static int cros_ec_regulator_get_voltage(struct regulator_dev *dev)
+{
+ struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+ struct ec_params_regulator_get_voltage cmd = {
+ .index = data->index,
+ };
+ struct ec_response_regulator_get_voltage resp;
+ int ret;
+
+ ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_VOLTAGE, &cmd,
+ sizeof(cmd), &resp, sizeof(resp));
+ if (ret < 0)
+ return ret;
+ return resp.voltage_mv * 1000;
+}
+
+static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV,
+ int max_uV, unsigned int *selector)
+{
+ struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
+ int min_mV = DIV_ROUND_UP(min_uV, 1000);
+ int max_mV = max_uV / 1000;
+ struct ec_params_regulator_set_voltage cmd = {
+ .index = data->index,
+ .min_mv = min_mV,
+ .max_mv = max_mV,
+ };
+
+ if (min_mV > max_mV)
+ return -EINVAL;
+ return cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_SET_VOLTAGE, &cmd,
+ sizeof(cmd), NULL, 0);
+}
+
+static struct regulator_ops cros_ec_regulator_voltage_ops = {
+ .enable = cros_ec_regulator_enable,
+ .disable = cros_ec_regulator_disable,
+ .is_enabled = cros_ec_regulator_is_enabled,
+ .list_voltage = cros_ec_regulator_list_voltage,
+ .get_voltage = cros_ec_regulator_get_voltage,
+ .set_voltage = cros_ec_regulator_set_voltage,
+};
+
+static int cros_ec_regulator_init_info(struct device *dev,
+ struct cros_ec_regulator_data *data)
+{
+ struct ec_params_regulator_get_info cmd = {
+ .index = data->index,
+ };
+ struct ec_response_regulator_get_info resp;
+ int ret;
+
+ ret = cros_ec_cmd(data->ec_dev, 0, EC_CMD_REGULATOR_GET_INFO, &cmd,
+ sizeof(cmd), &resp, sizeof(resp));
+ if (ret < 0)
+ return ret;
+
+ data->num_voltages =
+ min_t(u16, ARRAY_SIZE(resp.voltages_mv), resp.num_voltages);
+ data->voltages_mV =
+ devm_kmemdup(dev, resp.voltages_mv,
+ sizeof(u16) * data->num_voltages, GFP_KERNEL);
+ data->desc.n_voltages = data->num_voltages;
+ data->desc.name = kstrndup(resp.name, sizeof(resp.name), GFP_KERNEL);
+ if (!data->desc.name)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int cros_ec_regulator_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct cros_ec_regulator_data *drvdata;
+ struct regulator_init_data *init_data;
+ struct regulator_config cfg = {};
+ struct regulator_desc *desc;
+ int ret;
+
+ drvdata = devm_kzalloc(
+ &pdev->dev, sizeof(struct cros_ec_regulator_data), GFP_KERNEL);
+ if (!drvdata)
+ return -ENOMEM;
+
+ drvdata->ec_dev = dev_get_drvdata(dev->parent);
+ desc = &drvdata->desc;
+
+ init_data = of_get_regulator_init_data(dev, np, desc);
+ if (!init_data)
+ return -EINVAL;
+
+ ret = of_property_read_u32(np, "google,remote-regulator",
+ &drvdata->index);
+ if (ret < 0)
+ return ret;
+
+ desc->owner = THIS_MODULE;
+ desc->type = REGULATOR_VOLTAGE;
+ desc->ops = &cros_ec_regulator_voltage_ops;
+
+ ret = cros_ec_regulator_init_info(dev, drvdata);
+ if (ret < 0)
+ return ret;
+
+ cfg.dev = &pdev->dev;
+ cfg.init_data = init_data;
+ cfg.driver_data = drvdata;
+ cfg.of_node = np;
+
+ drvdata->dev = regulator_register(&drvdata->desc, &cfg);
+ if (IS_ERR(drvdata->dev)) {
+ ret = PTR_ERR(drvdata->dev);
+ dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
+ goto free_name;
+ }
+
+ platform_set_drvdata(pdev, drvdata);
+
+ return 0;
+
+free_name:
+ kfree(desc->name);
+ return ret;
+}
+
+static int cros_ec_regulator_remove(struct platform_device *pdev)
+{
+ struct cros_ec_regulator_data *drvdata = platform_get_drvdata(pdev);
+
+ kfree(drvdata->desc.name);
+
+ return 0;
+}
+
+#if defined(CONFIG_OF)
+static const struct of_device_id regulator_cros_ec_of_match[] = {
+ { .compatible = "regulator-cros-ec", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match);
+#endif
+
+static struct platform_driver cros_ec_regulator_driver = {
+ .probe = cros_ec_regulator_probe,
+ .remove = cros_ec_regulator_remove,
+ .driver = {
+ .name = "cros-ec-regulator",
+ .of_match_table = of_match_ptr(regulator_cros_ec_of_match),
+ },
+};
+
+module_platform_driver(cros_ec_regulator_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ChromeOS EC controlled regulator");
diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index 69210881ebac..a417b51b5764 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -5430,6 +5430,88 @@ struct ec_response_rollback_info {
/* Issue AP reset */
#define EC_CMD_AP_RESET 0x0125
+/*****************************************************************************/
+/* Voltage regulator controls */
+
+/*
+ * Get basic info of voltage regulator for given index.
+ *
+ * Returns the regulator name and supported voltage list in mV.
+ */
+#define EC_CMD_REGULATOR_GET_INFO 0x012B
+
+/* Maximum length of regulator name */
+#define EC_REGULATOR_NAME_MAX_LEN 16
+
+/* Maximum length of the supported voltage list. */
+#define EC_REGULATOR_VOLTAGE_MAX_COUNT 16
+
+struct ec_params_regulator_get_info {
+ uint32_t index;
+} __ec_align4;
+
+struct ec_response_regulator_get_info {
+ char name[EC_REGULATOR_NAME_MAX_LEN];
+ uint16_t num_voltages;
+ uint16_t voltages_mv[EC_REGULATOR_VOLTAGE_MAX_COUNT];
+} __ec_align1;
+
+/*
+ * Configure the regulator as enabled / disabled.
+ */
+#define EC_CMD_REGULATOR_ENABLE 0x012C
+
+struct ec_params_regulator_enable {
+ uint32_t index;
+ uint8_t enable;
+} __ec_align4;
+
+/*
+ * Query if the regulator is enabled.
+ *
+ * Returns 1 if the regulator is enabled, 0 if not.
+ */
+#define EC_CMD_REGULATOR_IS_ENABLED 0x012D
+
+struct ec_params_regulator_is_enabled {
+ uint32_t index;
+} __ec_align4;
+
+struct ec_response_regulator_is_enabled {
+ uint8_t enabled;
+} __ec_align1;
+
+/*
+ * Set voltage for the voltage regulator within the range specified.
+ *
+ * The driver should select the voltage in range closest to min_mv.
+ *
+ * Also note that this might be called before the regulator is enabled, and the
+ * setting should be in effect after the regulator is enabled.
+ */
+#define EC_CMD_REGULATOR_SET_VOLTAGE 0x012E
+
+struct ec_params_regulator_set_voltage {
+ uint32_t index;
+ uint32_t min_mv;
+ uint32_t max_mv;
+} __ec_align4;
+
+/*
+ * Get the currently configured voltage for the voltage regulator.
+ *
+ * Note that this might be called before the regulator is enabled.
+ */
+#define EC_CMD_REGULATOR_GET_VOLTAGE 0x012F
+
+struct ec_params_regulator_get_voltage {
+ uint32_t index;
+} __ec_align4;
+
+struct ec_response_regulator_get_voltage {
+ uint32_t voltage_mv;
+} __ec_align4;
+
/*****************************************************************************/
/* The command range 0x200-0x2FF is reserved for Rotor. */
--
2.27.0.278.ge193c7cf3a9-goog
On Tue, Jun 09, 2020 at 03:59:55PM +0800, Pi-Hsun Shih wrote:
> +static int cros_ec_regulator_set_state(struct regulator_dev *dev, bool enable)
> +{
> + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> + struct ec_params_regulator_enable cmd = {
> + .index = data->index,
> + .enable = enable ? 1 : 0,
The ternery operator is totally redundant here.
> +static int cros_ec_regulator_enable(struct regulator_dev *dev)
> +{
> + return cros_ec_regulator_set_state(dev, true);
> +}
> +static int cros_ec_regulator_disable(struct regulator_dev *dev)
> +{
> + return cros_ec_regulator_set_state(dev, false);
> +}
I'm not sure that the shared function is really worthwhile though,
there's not really enough in it and certainly not anything complicated.
> +static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV,
> + int max_uV, unsigned int *selector)
> +{
> + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> + int min_mV = DIV_ROUND_UP(min_uV, 1000);
> + int max_mV = max_uV / 1000;
> + struct ec_params_regulator_set_voltage cmd = {
> + .index = data->index,
> + .min_mv = min_mV,
> + .max_mv = max_mV,
> + };
> +
> + if (min_mV > max_mV)
> + return -EINVAL;
The core will do this for you.
> + ret = of_property_read_u32(np, "google,remote-regulator",
> + &drvdata->index);
> + if (ret < 0)
> + return ret;
This remote-regulator property is a bit weird, it feels like it should
be a reg property on a bus.
> +#if defined(CONFIG_OF)
> +static const struct of_device_id regulator_cros_ec_of_match[] = {
> + { .compatible = "regulator-cros-ec", },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match);
> +#endif
Your compatible is google,regulator-cros-ec.
Thanks for the review, some inline reply:
On Tue, Jun 9, 2020 at 7:19 PM Mark Brown <[email protected]> wrote:
>
> On Tue, Jun 09, 2020 at 03:59:55PM +0800, Pi-Hsun Shih wrote:
>
> > +static int cros_ec_regulator_set_state(struct regulator_dev *dev, bool enable)
> > +{
> > + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> > + struct ec_params_regulator_enable cmd = {
> > + .index = data->index,
> > + .enable = enable ? 1 : 0,
>
> The ternery operator is totally redundant here.
Ack, would fix in v2.
>
> > +static int cros_ec_regulator_enable(struct regulator_dev *dev)
> > +{
> > + return cros_ec_regulator_set_state(dev, true);
> > +}
>
> > +static int cros_ec_regulator_disable(struct regulator_dev *dev)
> > +{
> > + return cros_ec_regulator_set_state(dev, false);
> > +}
>
> I'm not sure that the shared function is really worthwhile though,
> there's not really enough in it and certainly not anything complicated.
Ack, would fix in v2.
>
> > +static int cros_ec_regulator_set_voltage(struct regulator_dev *dev, int min_uV,
> > + int max_uV, unsigned int *selector)
> > +{
> > + struct cros_ec_regulator_data *data = rdev_get_drvdata(dev);
> > + int min_mV = DIV_ROUND_UP(min_uV, 1000);
> > + int max_mV = max_uV / 1000;
> > + struct ec_params_regulator_set_voltage cmd = {
> > + .index = data->index,
> > + .min_mv = min_mV,
> > + .max_mv = max_mV,
> > + };
> > +
> > + if (min_mV > max_mV)
> > + return -EINVAL;
>
> The core will do this for you.
Since I'm doing DIV_ROUND_UP for the min_mV, so this may happen if the
min_uV~max_uV range given by the core doesn't contain any value that
can be represented exactly in mV.
>
> > + ret = of_property_read_u32(np, "google,remote-regulator",
> > + &drvdata->index);
> > + if (ret < 0)
> > + return ret;
>
> This remote-regulator property is a bit weird, it feels like it should
> be a reg property on a bus.
Ok I'll change this to reg property in v2.
>
> > +#if defined(CONFIG_OF)
> > +static const struct of_device_id regulator_cros_ec_of_match[] = {
> > + { .compatible = "regulator-cros-ec", },
> > + {},
> > +};
> > +MODULE_DEVICE_TABLE(of, regulator_cros_ec_of_match);
> > +#endif
>
> Your compatible is google,regulator-cros-ec.
Ack, would fix in v2.
On Wed, Jun 10, 2020 at 12:31:53PM +0800, Pi-Hsun Shih wrote:
> On Tue, Jun 9, 2020 at 7:19 PM Mark Brown <[email protected]> wrote:
> > On Tue, Jun 09, 2020 at 03:59:55PM +0800, Pi-Hsun Shih wrote:
> > > + int min_mV = DIV_ROUND_UP(min_uV, 1000);
> > > + int max_mV = max_uV / 1000;
> > > + struct ec_params_regulator_set_voltage cmd = {
> > > + .index = data->index,
> > > + .min_mv = min_mV,
> > > + .max_mv = max_mV,
> > > + };
> > > +
> > > + if (min_mV > max_mV)
> > > + return -EINVAL;
> > The core will do this for you.
> Since I'm doing DIV_ROUND_UP for the min_mV, so this may happen if the
> min_uV~max_uV range given by the core doesn't contain any value that
> can be represented exactly in mV.
This isn't clear from the code - I'd add a comment or move the division
to be next to the check.