Merge branch 'for-6.2/mcp2221' into for-linus

- iio support for the MCP2221 HID driver (Matt Ranostay)

2 files changed, 290 insertions, 26 deletions

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 185a077d59cdd..17cce4c50e8dc 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -1252,7 +1252,8 @@ config HID_ALPS
 config HID_MCP2221
 	tristate "Microchip MCP2221 HID USB-to-I2C/SMbus host support"
 	depends on USB_HID && I2C
-	depends on GPIOLIB
+	imply GPIOLIB
+	imply IIO
 	help
 	Provides I2C and SMBUS host adapter functionality over USB-HID
 	through MCP2221 device.
diff --git a/drivers/hid/hid-mcp2221.c b/drivers/hid/hid-mcp2221.c
index de52e9f7bb8cb..5886543b17f34 100644
--- a/drivers/hid/hid-mcp2221.c
+++ b/drivers/hid/hid-mcp2221.c
@@ -10,12 +10,14 @@
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/mutex.h>
+#include <linux/bitfield.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/hid.h>
 #include <linux/hidraw.h>
 #include <linux/i2c.h>
 #include <linux/gpio/driver.h>
+#include <linux/iio/iio.h>
 #include "hid-ids.h"
 
 /* Commands codes in a raw output report */
@@ -30,6 +32,9 @@ enum {
 	MCP2221_I2C_CANCEL = 0x10,
 	MCP2221_GPIO_SET = 0x50,
 	MCP2221_GPIO_GET = 0x51,
+	MCP2221_SET_SRAM_SETTINGS = 0x60,
+	MCP2221_GET_SRAM_SETTINGS = 0x61,
+	MCP2221_READ_FLASH_DATA = 0xb0,
 };
 
 /* Response codes in a raw input report */
@@ -89,6 +94,7 @@ struct mcp2221 {
 	struct i2c_adapter adapter;
 	struct mutex lock;
 	struct completion wait_in_report;
+	struct delayed_work init_work;
 	u8 *rxbuf;
 	u8 txbuf[64];
 	int rxbuf_idx;
@@ -97,6 +103,18 @@ struct mcp2221 {
 	struct gpio_chip *gc;
 	u8 gp_idx;
 	u8 gpio_dir;
+	u8 mode[4];
+#if IS_REACHABLE(CONFIG_IIO)
+	struct iio_chan_spec iio_channels[3];
+	u16 adc_values[3];
+	u8 adc_scale;
+	u8 dac_value;
+	u16 dac_scale;
+#endif
+};
+
+struct mcp2221_iio {
+	struct mcp2221 *mcp;
 };
 
 /*
@@ -567,6 +585,7 @@ static const struct i2c_algorithm mcp_i2c_algo = {
 	.functionality = mcp_i2c_func,
 };
 
+#if IS_REACHABLE(CONFIG_GPIOLIB)
 static int mcp_gpio_get(struct gpio_chip *gc,
 				unsigned int offset)
 {
@@ -670,6 +689,7 @@ static int mcp_gpio_get_direction(struct gpio_chip *gc,
 
 	return GPIO_LINE_DIRECTION_OUT;
 }
+#endif
 
 /* Gives current state of i2c engine inside mcp2221 */
 static int mcp_get_i2c_eng_state(struct mcp2221 *mcp,
@@ -745,6 +765,9 @@ static int mcp2221_raw_event(struct hid_device *hdev,
 				break;
 			}
 			mcp->status = mcp_get_i2c_eng_state(mcp, data, 8);
+#if IS_REACHABLE(CONFIG_IIO)
+			memcpy(&mcp->adc_values, &data[50], sizeof(mcp->adc_values));
+#endif
 			break;
 		default:
 			mcp->status = -EIO;
@@ -816,6 +839,69 @@ static int mcp2221_raw_event(struct hid_device *hdev,
 		complete(&mcp->wait_in_report);
 		break;
 
+	case MCP2221_SET_SRAM_SETTINGS:
+		switch (data[1]) {
+		case MCP2221_SUCCESS:
+			mcp->status = 0;
+			break;
+		default:
+			mcp->status = -EAGAIN;
+		}
+		complete(&mcp->wait_in_report);
+		break;
+
+	case MCP2221_GET_SRAM_SETTINGS:
+		switch (data[1]) {
+		case MCP2221_SUCCESS:
+			memcpy(&mcp->mode, &data[22], 4);
+#if IS_REACHABLE(CONFIG_IIO)
+			mcp->dac_value = data[6] & GENMASK(4, 0);
+#endif
+			mcp->status = 0;
+			break;
+		default:
+			mcp->status = -EAGAIN;
+		}
+		complete(&mcp->wait_in_report);
+		break;
+
+	case MCP2221_READ_FLASH_DATA:
+		switch (data[1]) {
+		case MCP2221_SUCCESS:
+			mcp->status = 0;
+
+			/* Only handles CHIP SETTINGS subpage currently */
+			if (mcp->txbuf[1] != 0) {
+				mcp->status = -EIO;
+				break;
+			}
+
+#if IS_REACHABLE(CONFIG_IIO)
+			{
+				u8 tmp;
+				/* DAC scale value */
+				tmp = FIELD_GET(GENMASK(7, 6), data[6]);
+				if ((data[6] & BIT(5)) && tmp)
+					mcp->dac_scale = tmp + 4;
+				else
+					mcp->dac_scale = 5;
+
+				/* ADC scale value */
+				tmp = FIELD_GET(GENMASK(4, 3), data[7]);
+				if ((data[7] & BIT(2)) && tmp)
+					mcp->adc_scale = tmp - 1;
+				else
+					mcp->adc_scale = 0;
+			}
+#endif
+
+			break;
+		default:
+			mcp->status = -EAGAIN;
+		}
+		complete(&mcp->wait_in_report);
+		break;
+
 	default:
 		mcp->status = -EIO;
 		complete(&mcp->wait_in_report);
@@ -824,6 +910,190 @@ static int mcp2221_raw_event(struct hid_device *hdev,
 	return 1;
 }
 
+/* Device resource managed function for HID unregistration */
+static void mcp2221_hid_unregister(void *ptr)
+{
+	struct hid_device *hdev = ptr;
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+/* This is needed to be sure hid_hw_stop() isn't called twice by the subsystem */
+static void mcp2221_remove(struct hid_device *hdev)
+{
+}
+
+#if IS_REACHABLE(CONFIG_IIO)
+static int mcp2221_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *channel, int *val,
+			    int *val2, long mask)
+{
+	struct mcp2221_iio *priv = iio_priv(indio_dev);
+	struct mcp2221 *mcp = priv->mcp;
+	int ret;
+
+	if (mask == IIO_CHAN_INFO_SCALE) {
+		if (channel->output)
+			*val = 1 << mcp->dac_scale;
+		else
+			*val = 1 << mcp->adc_scale;
+
+		return IIO_VAL_INT;
+	}
+
+	mutex_lock(&mcp->lock);
+
+	if (channel->output) {
+		*val = mcp->dac_value;
+		ret = IIO_VAL_INT;
+	} else {
+		/* Read ADC values */
+		ret = mcp_chk_last_cmd_status(mcp);
+
+		if (!ret) {
+			*val = le16_to_cpu((__force __le16) mcp->adc_values[channel->address]);
+			if (*val >= BIT(10))
+				ret =  -EINVAL;
+			else
+				ret = IIO_VAL_INT;
+		}
+	}
+
+	mutex_unlock(&mcp->lock);
+
+	return ret;
+}
+
+static int mcp2221_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val, int val2, long mask)
+{
+	struct mcp2221_iio *priv = iio_priv(indio_dev);
+	struct mcp2221 *mcp = priv->mcp;
+	int ret;
+
+	if (val < 0 || val >= BIT(5))
+		return -EINVAL;
+
+	mutex_lock(&mcp->lock);
+
+	memset(mcp->txbuf, 0, 12);
+	mcp->txbuf[0] = MCP2221_SET_SRAM_SETTINGS;
+	mcp->txbuf[4] = BIT(7) | val;
+
+	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 12);
+	if (!ret)
+		mcp->dac_value = val;
+
+	mutex_unlock(&mcp->lock);
+
+	return ret;
+}
+
+static const struct iio_info mcp2221_info = {
+	.read_raw = &mcp2221_read_raw,
+	.write_raw = &mcp2221_write_raw,
+};
+
+static int mcp_iio_channels(struct mcp2221 *mcp)
+{
+	int idx, cnt = 0;
+	bool dac_created = false;
+
+	/* GP0 doesn't have ADC/DAC alternative function */
+	for (idx = 1; idx < MCP_NGPIO; idx++) {
+		struct iio_chan_spec *chan = &mcp->iio_channels[cnt];
+
+		switch (mcp->mode[idx]) {
+		case 2:
+			chan->address = idx - 1;
+			chan->channel = cnt++;
+			break;
+		case 3:
+			/* GP1 doesn't have DAC alternative function */
+			if (idx == 1 || dac_created)
+				continue;
+			/* DAC1 and DAC2 outputs are connected to the same DAC */
+			dac_created = true;
+			chan->output = 1;
+			cnt++;
+			break;
+		default:
+			continue;
+		};
+
+		chan->type = IIO_VOLTAGE;
+		chan->indexed = 1;
+		chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
+		chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
+		chan->scan_index = -1;
+	}
+
+	return cnt;
+}
+
+static void mcp_init_work(struct work_struct *work)
+{
+	struct iio_dev *indio_dev;
+	struct mcp2221 *mcp = container_of(work, struct mcp2221, init_work.work);
+	struct mcp2221_iio *data;
+	static int retries = 5;
+	int ret, num_channels;
+
+	hid_hw_power(mcp->hdev, PM_HINT_FULLON);
+	mutex_lock(&mcp->lock);
+
+	mcp->txbuf[0] = MCP2221_GET_SRAM_SETTINGS;
+	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 1);
+
+	if (ret == -EAGAIN)
+		goto reschedule_task;
+
+	num_channels = mcp_iio_channels(mcp);
+	if (!num_channels)
+		goto unlock;
+
+	mcp->txbuf[0] = MCP2221_READ_FLASH_DATA;
+	mcp->txbuf[1] = 0;
+	ret = mcp_send_data_req_status(mcp, mcp->txbuf, 2);
+
+	if (ret == -EAGAIN)
+		goto reschedule_task;
+
+	indio_dev = devm_iio_device_alloc(&mcp->hdev->dev, sizeof(*data));
+	if (!indio_dev)
+		goto unlock;
+
+	data = iio_priv(indio_dev);
+	data->mcp = mcp;
+
+	indio_dev->name = "mcp2221";
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &mcp2221_info;
+	indio_dev->channels = mcp->iio_channels;
+	indio_dev->num_channels = num_channels;
+
+	devm_iio_device_register(&mcp->hdev->dev, indio_dev);
+
+unlock:
+	mutex_unlock(&mcp->lock);
+	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
+
+	return;
+
+reschedule_task:
+	mutex_unlock(&mcp->lock);
+	hid_hw_power(mcp->hdev, PM_HINT_NORMAL);
+
+	if (!retries--)
+		return;
+
+	/* Device is not ready to read SRAM or FLASH data, try again */
+	schedule_delayed_work(&mcp->init_work, msecs_to_jiffies(100));
+}
+#endif
+
 static int mcp2221_probe(struct hid_device *hdev,
 					const struct hid_device_id *id)
 {
@@ -849,7 +1119,8 @@ static int mcp2221_probe(struct hid_device *hdev,
 	ret = hid_hw_open(hdev);
 	if (ret) {
 		hid_err(hdev, "can't open device\n");
-		goto err_hstop;
+		hid_hw_stop(hdev);
+		return ret;
 	}
 
 	mutex_init(&mcp->lock);
@@ -857,6 +1128,10 @@ static int mcp2221_probe(struct hid_device *hdev,
 	hid_set_drvdata(hdev, mcp);
 	mcp->hdev = hdev;
 
+	ret = devm_add_action_or_reset(&hdev->dev, mcp2221_hid_unregister, hdev);
+	if (ret)
+		return ret;
+
 	/* Set I2C bus clock diviser */
 	if (i2c_clk_freq > 400)
 		i2c_clk_freq = 400;
@@ -873,19 +1148,18 @@ static int mcp2221_probe(struct hid_device *hdev,
 			"MCP2221 usb-i2c bridge on hidraw%d",
 			((struct hidraw *)hdev->hidraw)->minor);
 
-	ret = i2c_add_adapter(&mcp->adapter);
+	ret = devm_i2c_add_adapter(&hdev->dev, &mcp->adapter);
 	if (ret) {
 		hid_err(hdev, "can't add usb-i2c adapter: %d\n", ret);
-		goto err_i2c;
+		return ret;
 	}
 	i2c_set_adapdata(&mcp->adapter, mcp);
 
+#if IS_REACHABLE(CONFIG_GPIOLIB)
 	/* Setup GPIO chip */
 	mcp->gc = devm_kzalloc(&hdev->dev, sizeof(*mcp->gc), GFP_KERNEL);
-	if (!mcp->gc) {
-		ret = -ENOMEM;
-		goto err_gc;
-	}
+	if (!mcp->gc)
+		return -ENOMEM;
 
 	mcp->gc->label = "mcp2221_gpio";
 	mcp->gc->direction_input = mcp_gpio_direction_input;
@@ -900,26 +1174,15 @@ static int mcp2221_probe(struct hid_device *hdev,
 
 	ret = devm_gpiochip_add_data(&hdev->dev, mcp->gc, mcp);
 	if (ret)
-		goto err_gc;
-
-	return 0;
-
-err_gc:
-	i2c_del_adapter(&mcp->adapter);
-err_i2c:
-	hid_hw_close(mcp->hdev);
-err_hstop:
-	hid_hw_stop(mcp->hdev);
-	return ret;
-}
+		return ret;
+#endif
 
-static void mcp2221_remove(struct hid_device *hdev)
-{
-	struct mcp2221 *mcp = hid_get_drvdata(hdev);
+#if IS_REACHABLE(CONFIG_IIO)
+	INIT_DELAYED_WORK(&mcp->init_work, mcp_init_work);
+	schedule_delayed_work(&mcp->init_work, msecs_to_jiffies(100));
+#endif
 
-	i2c_del_adapter(&mcp->adapter);
-	hid_hw_close(mcp->hdev);
-	hid_hw_stop(mcp->hdev);
+	return 0;
 }
 
 static const struct hid_device_id mcp2221_devices[] = {