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[v4,7/7] iio: pressure: bmp280: Add nvmem operations for BMP580

Message ID f3f453d9b2c0f7820ca9c56e24e2165b6c39bb67.1676823250.git.ang.iglesiasg@gmail.com
State Accepted
Commit accb9d05df394c38db2a1bab416ee25d6078ca5c
Headers show
Series Add support for pressure sensor Bosch BMP580 | expand

Commit Message

Angel Iglesias Feb. 19, 2023, 5:03 p.m. UTC 
The pressure sensor BMP580 contains a non-volatile memory that stores
trimming and configuration params. That memory provides an programmable
user range of three 2-byte words.

Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>

Comments

Jonathan Cameron Feb. 26, 2023, 1:31 p.m. UTC | #1 
On Sun, 19 Feb 2023 18:03:06 +0100
Angel Iglesias <ang.iglesiasg@gmail.com> wrote:

> The pressure sensor BMP580 contains a non-volatile memory that stores
> trimming and configuration params. That memory provides an programmable
> user range of three 2-byte words.
> 
> Signed-off-by: Angel Iglesias <ang.iglesiasg@gmail.com>

Trivial missing static marking in here... Fixed up whilst applying.

Whole series applied to the togreg branch of iio.git. Not that will only be pushed
out as testing until after rc1 (on which I'll rebase it).

Thanks,

Jonathan
>  
> +const int bmp580_nvmem_addrs[] = { 0x20, 0x21, 0x22 };
static
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Patch

diff --git a/drivers/iio/pressure/bmp280-core.c b/drivers/iio/pressure/bmp280-core.c
index a7d26d81ec08..1e7534d7c4a6 100644
--- a/drivers/iio/pressure/bmp280-core.c
+++ b/drivers/iio/pressure/bmp280-core.c
@@ -28,6 +28,7 @@ 
 #include <linux/bitfield.h>
 #include <linux/device.h>
 #include <linux/module.h>
+#include <linux/nvmem-provider.h>
 #include <linux/regmap.h>
 #include <linux/delay.h>
 #include <linux/iio/iio.h>
@@ -1284,6 +1285,80 @@  static int bmp580_soft_reset(struct bmp280_data *data)
 	return 0;
 }
 
+/**
+ * bmp580_nvm_operation() - Helper function to commit NVM memory operations
+ * @data: sensor data struct
+ * @is_write: flag to signal write operation
+ */
+static int bmp580_nvm_operation(struct bmp280_data *data, bool is_write)
+{
+	unsigned long timeout, poll;
+	unsigned int reg;
+	int ret;
+
+	/* Check NVM ready flag */
+	ret = regmap_read(data->regmap, BMP580_REG_STATUS, &reg);
+	if (ret) {
+		dev_err(data->dev, "failed to check nvm status\n");
+		return ret;
+	}
+	if (!(reg & BMP580_STATUS_NVM_RDY_MASK)) {
+		dev_err(data->dev, "sensor's nvm is not ready\n");
+		return -EIO;
+	}
+
+	/* Start NVM operation sequence */
+	ret = regmap_write(data->regmap, BMP580_REG_CMD, BMP580_CMD_NVM_OP_SEQ_0);
+	if (ret) {
+		dev_err(data->dev, "failed to send nvm operation's first sequence\n");
+		return ret;
+	}
+	if (is_write) {
+		/* Send NVM write sequence */
+		ret = regmap_write(data->regmap, BMP580_REG_CMD,
+				   BMP580_CMD_NVM_WRITE_SEQ_1);
+		if (ret) {
+			dev_err(data->dev, "failed to send nvm write sequence\n");
+			return ret;
+		}
+		/* Datasheet says on 4.8.1.2 it takes approximately 10ms */
+		poll = 2000;
+		timeout = 12000;
+	} else {
+		/* Send NVM read sequence */
+		ret = regmap_write(data->regmap, BMP580_REG_CMD,
+				   BMP580_CMD_NVM_READ_SEQ_1);
+		if (ret) {
+			dev_err(data->dev, "failed to send nvm read sequence\n");
+			return ret;
+		}
+		/* Datasheet says on 4.8.1.1 it takes approximately 200us */
+		poll = 50;
+		timeout = 400;
+	}
+	if (ret) {
+		dev_err(data->dev, "failed to write command sequence\n");
+		return -EIO;
+	}
+
+	/* Wait until NVM is ready again */
+	ret = regmap_read_poll_timeout(data->regmap, BMP580_REG_STATUS, reg,
+				       (reg & BMP580_STATUS_NVM_RDY_MASK),
+				       poll, timeout);
+	if (ret) {
+		dev_err(data->dev, "error checking nvm operation status\n");
+		return ret;
+	}
+
+	/* Check NVM error flags */
+	if ((reg & BMP580_STATUS_NVM_ERR_MASK) || (reg & BMP580_STATUS_NVM_CMD_ERR_MASK)) {
+		dev_err(data->dev, "error processing nvm operation\n");
+		return -EIO;
+	}
+
+	return 0;
+}
+
 /*
  * Contrary to previous sensors families, compensation algorithm is builtin.
  * We are only required to read the register raw data and adapt the ranges
@@ -1379,8 +1454,140 @@  static const int bmp580_odr_table[][2] = {
 	[BMP580_ODR_0_125HZ] =	{0, 125000},
 };
 
+const int bmp580_nvmem_addrs[] = { 0x20, 0x21, 0x22 };
+
+static int bmp580_nvmem_read(void *priv, unsigned int offset, void *val,
+			     size_t bytes)
+{
+	struct bmp280_data *data = priv;
+	u16 *dst = val;
+	int ret, addr;
+
+	pm_runtime_get_sync(data->dev);
+	mutex_lock(&data->lock);
+
+	/* Set sensor in standby mode */
+	ret = regmap_update_bits(data->regmap, BMP580_REG_ODR_CONFIG,
+				 BMP580_MODE_MASK | BMP580_ODR_DEEPSLEEP_DIS,
+				 BMP580_ODR_DEEPSLEEP_DIS |
+				 FIELD_PREP(BMP580_MODE_MASK, BMP580_MODE_SLEEP));
+	if (ret) {
+		dev_err(data->dev, "failed to change sensor to standby mode\n");
+		goto exit;
+	}
+	/* Wait standby transition time */
+	usleep_range(2500, 3000);
+
+	while (bytes >= sizeof(*dst)) {
+		addr = bmp580_nvmem_addrs[offset / sizeof(*dst)];
+
+		ret = regmap_write(data->regmap, BMP580_REG_NVM_ADDR,
+				   FIELD_PREP(BMP580_NVM_ROW_ADDR_MASK, addr));
+		if (ret) {
+			dev_err(data->dev, "error writing nvm address\n");
+			goto exit;
+		}
+
+		ret = bmp580_nvm_operation(data, false);
+		if (ret)
+			goto exit;
+
+		ret = regmap_bulk_read(data->regmap, BMP580_REG_NVM_DATA_LSB, &data->le16,
+				       sizeof(data->le16));
+		if (ret) {
+			dev_err(data->dev, "error reading nvm data regs\n");
+			goto exit;
+		}
+
+		*dst++ = le16_to_cpu(data->le16);
+		bytes -= sizeof(*dst);
+		offset += sizeof(*dst);
+	}
+exit:
+	/* Restore chip config */
+	data->chip_info->chip_config(data);
+	mutex_unlock(&data->lock);
+	pm_runtime_mark_last_busy(data->dev);
+	pm_runtime_put_autosuspend(data->dev);
+	return ret;
+}
+
+static int bmp580_nvmem_write(void *priv, unsigned int offset, void *val,
+			      size_t bytes)
+{
+	struct bmp280_data *data = priv;
+	u16 *buf = val;
+	int ret, addr;
+
+	pm_runtime_get_sync(data->dev);
+	mutex_lock(&data->lock);
+
+	/* Set sensor in standby mode */
+	ret = regmap_update_bits(data->regmap, BMP580_REG_ODR_CONFIG,
+				 BMP580_MODE_MASK | BMP580_ODR_DEEPSLEEP_DIS,
+				 BMP580_ODR_DEEPSLEEP_DIS |
+				 FIELD_PREP(BMP580_MODE_MASK, BMP580_MODE_SLEEP));
+	if (ret) {
+		dev_err(data->dev, "failed to change sensor to standby mode\n");
+		goto exit;
+	}
+	/* Wait standby transition time */
+	usleep_range(2500, 3000);
+
+	while (bytes >= sizeof(*buf)) {
+		addr = bmp580_nvmem_addrs[offset / sizeof(*buf)];
+
+		ret = regmap_write(data->regmap, BMP580_REG_NVM_ADDR, BMP580_NVM_PROG_EN |
+				   FIELD_PREP(BMP580_NVM_ROW_ADDR_MASK, addr));
+		if (ret) {
+			dev_err(data->dev, "error writing nvm address\n");
+			goto exit;
+		}
+		data->le16 = cpu_to_le16(*buf++);
+
+		ret = regmap_bulk_write(data->regmap, BMP580_REG_NVM_DATA_LSB, &data->le16,
+					sizeof(data->le16));
+		if (ret) {
+			dev_err(data->dev, "error writing LSB NVM data regs\n");
+			goto exit;
+		}
+
+		ret = bmp580_nvm_operation(data, true);
+		if (ret)
+			goto exit;
+
+		/* Disable programming mode bit */
+		ret = regmap_update_bits(data->regmap, BMP580_REG_NVM_ADDR,
+					 BMP580_NVM_PROG_EN, 0);
+		if (ret) {
+			dev_err(data->dev, "error resetting nvm write\n");
+			goto exit;
+		}
+
+		bytes -= sizeof(*buf);
+		offset += sizeof(*buf);
+	}
+exit:
+	/* Restore chip config */
+	data->chip_info->chip_config(data);
+	mutex_unlock(&data->lock);
+	pm_runtime_mark_last_busy(data->dev);
+	pm_runtime_put_autosuspend(data->dev);
+	return ret;
+}
+
 static int bmp580_preinit(struct bmp280_data *data)
 {
+	struct nvmem_config config = {
+		.dev = data->dev,
+		.priv = data,
+		.name = "bmp580_nvmem",
+		.word_size = sizeof(u16),
+		.stride = sizeof(u16),
+		.size = 3 * sizeof(u16),
+		.reg_read = bmp580_nvmem_read,
+		.reg_write = bmp580_nvmem_write,
+	};
 	unsigned int reg;
 	int ret;
 
@@ -1408,7 +1615,8 @@  static int bmp580_preinit(struct bmp280_data *data)
 		return -EIO;
 	}
 
-	return 0;
+	/* Register nvmem device */
+	return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
 }
 
 static int bmp580_chip_config(struct bmp280_data *data)
diff --git a/drivers/iio/pressure/bmp280.h b/drivers/iio/pressure/bmp280.h
index cd4c5be36ed7..5c0563ce7572 100644
--- a/drivers/iio/pressure/bmp280.h
+++ b/drivers/iio/pressure/bmp280.h
@@ -104,6 +104,9 @@ 
 #define BMP580_FILTER_63X		6
 #define BMP580_FILTER_127X		7
 
+#define BMP580_NVM_ROW_ADDR_MASK	GENMASK(5, 0)
+#define BMP580_NVM_PROG_EN		BIT(6)
+
 #define BMP580_TEMP_SKIPPED		0x7f7f7f
 #define BMP580_PRESS_SKIPPED		0x7f7f7f