Merge tag 'staging-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging and IIO fixes from Greg KH:
 "Here is a bunch of IIO driver fixes, and some smaller staging driver
  fixes, for 5.1-rc6. The IIO fixes were delayed due to my vacation, but
  all resolve a number of reported issues and have been in linux-next
  for a few weeks with no reported issues.

  The other staging driver fixes are all tiny, resolving some reported
  issues in the comedi and most drivers, as well as some erofs fixes.

  All of these patches have been in linux-next with no reported issues"

* tag 'staging-5.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (24 commits)
  staging: comedi: ni_usb6501: Fix possible double-free of ->usb_rx_buf
  staging: comedi: ni_usb6501: Fix use of uninitialized mutex
  staging: erofs: fix unexpected out-of-bound data access
  staging: comedi: vmk80xx: Fix possible double-free of ->usb_rx_buf
  staging: comedi: vmk80xx: Fix use of uninitialized semaphore
  staging: most: core: use device description as name
  iio: core: fix a possible circular locking dependency
  iio: ad_sigma_delta: select channel when reading register
  iio: pms7003: select IIO_TRIGGERED_BUFFER
  iio: cros_ec: Fix the maths for gyro scale calculation
  iio: adc: xilinx: prevent touching unclocked h/w on remove
  iio: adc: xilinx: fix potential use-after-free on probe
  iio: adc: xilinx: fix potential use-after-free on remove
  iio: dac: mcp4725: add missing powerdown bits in store eeprom
  io: accel: kxcjk1013: restore the range after resume.
  iio:chemical:bme680: Fix SPI read interface
  iio:chemical:bme680: Fix, report temperature in millidegrees
  iio: chemical: fix missing Kconfig block for sgp30
  iio: adc: at91: disable adc channel interrupt in timeout case
  iio: gyro: mpu3050: fix chip ID reading
  ...

1 files changed, 78 insertions, 37 deletions

diff --git a/drivers/iio/chemical/bme680_spi.c b/drivers/iio/chemical/bme680_spi.c
index d0b7bdd3f066..3b838068a7e4 100644
--- a/drivers/iio/chemical/bme680_spi.c
+++ b/drivers/iio/chemical/bme680_spi.c
@@ -12,28 +12,93 @@
 
 #include "bme680.h"
 
+struct bme680_spi_bus_context {
+	struct spi_device *spi;
+	u8 current_page;
+};
+
+/*
+ * In SPI mode there are only 7 address bits, a "page" register determines
+ * which part of the 8-bit range is active. This function looks at the address
+ * and writes the page selection bit if needed
+ */
+static int bme680_regmap_spi_select_page(
+	struct bme680_spi_bus_context *ctx, u8 reg)
+{
+	struct spi_device *spi = ctx->spi;
+	int ret;
+	u8 buf[2];
+	u8 page = (reg & 0x80) ? 0 : 1; /* Page "1" is low range */
+
+	if (page == ctx->current_page)
+		return 0;
+
+	/*
+	 * Data sheet claims we're only allowed to change bit 4, so we must do
+	 * a read-modify-write on each and every page select
+	 */
+	buf[0] = BME680_REG_STATUS;
+	ret = spi_write_then_read(spi, buf, 1, buf + 1, 1);
+	if (ret < 0) {
+		dev_err(&spi->dev, "failed to set page %u\n", page);
+		return ret;
+	}
+
+	buf[0] = BME680_REG_STATUS;
+	if (page)
+		buf[1] |= BME680_SPI_MEM_PAGE_BIT;
+	else
+		buf[1] &= ~BME680_SPI_MEM_PAGE_BIT;
+
+	ret = spi_write(spi, buf, 2);
+	if (ret < 0) {
+		dev_err(&spi->dev, "failed to set page %u\n", page);
+		return ret;
+	}
+
+	ctx->current_page = page;
+
+	return 0;
+}
+
 static int bme680_regmap_spi_write(void *context, const void *data,
 				   size_t count)
 {
-	struct spi_device *spi = context;
+	struct bme680_spi_bus_context *ctx = context;
+	struct spi_device *spi = ctx->spi;
+	int ret;
 	u8 buf[2];
 
 	memcpy(buf, data, 2);
+
+	ret = bme680_regmap_spi_select_page(ctx, buf[0]);
+	if (ret)
+		return ret;
+
 	/*
 	 * The SPI register address (= full register address without bit 7)
 	 * and the write command (bit7 = RW = '0')
 	 */
 	buf[0] &= ~0x80;
 
-	return spi_write_then_read(spi, buf, 2, NULL, 0);
+	return spi_write(spi, buf, 2);
 }
 
 static int bme680_regmap_spi_read(void *context, const void *reg,
 				  size_t reg_size, void *val, size_t val_size)
 {
-	struct spi_device *spi = context;
+	struct bme680_spi_bus_context *ctx = context;
+	struct spi_device *spi = ctx->spi;
+	int ret;
+	u8 addr = *(const u8 *)reg;
+
+	ret = bme680_regmap_spi_select_page(ctx, addr);
+	if (ret)
+		return ret;
 
-	return spi_write_then_read(spi, reg, reg_size, val, val_size);
+	addr |= 0x80; /* bit7 = RW = '1' */
+
+	return spi_write_then_read(spi, &addr, 1, val, val_size);
 }
 
 static struct regmap_bus bme680_regmap_bus = {
@@ -46,8 +111,8 @@ static struct regmap_bus bme680_regmap_bus = {
 static int bme680_spi_probe(struct spi_device *spi)
 {
 	const struct spi_device_id *id = spi_get_device_id(spi);
+	struct bme680_spi_bus_context *bus_context;
 	struct regmap *regmap;
-	unsigned int val;
 	int ret;
 
 	spi->bits_per_word = 8;
@@ -57,45 +122,21 @@ static int bme680_spi_probe(struct spi_device *spi)
 		return ret;
 	}
 
+	bus_context = devm_kzalloc(&spi->dev, sizeof(*bus_context), GFP_KERNEL);
+	if (!bus_context)
+		return -ENOMEM;
+
+	bus_context->spi = spi;
+	bus_context->current_page = 0xff; /* Undefined on warm boot */
+
 	regmap = devm_regmap_init(&spi->dev, &bme680_regmap_bus,
-				  &spi->dev, &bme680_regmap_config);
+				  bus_context, &bme680_regmap_config);
 	if (IS_ERR(regmap)) {
 		dev_err(&spi->dev, "Failed to register spi regmap %d\n",
 				(int)PTR_ERR(regmap));
 		return PTR_ERR(regmap);
 	}
 
-	ret = regmap_write(regmap, BME680_REG_SOFT_RESET_SPI,
-			   BME680_CMD_SOFTRESET);
-	if (ret < 0) {
-		dev_err(&spi->dev, "Failed to reset chip\n");
-		return ret;
-	}
-
-	/* after power-on reset, Page 0(0x80-0xFF) of spi_mem_page is active */
-	ret = regmap_read(regmap, BME680_REG_CHIP_SPI_ID, &val);
-	if (ret < 0) {
-		dev_err(&spi->dev, "Error reading SPI chip ID\n");
-		return ret;
-	}
-
-	if (val != BME680_CHIP_ID_VAL) {
-		dev_err(&spi->dev, "Wrong chip ID, got %x expected %x\n",
-				val, BME680_CHIP_ID_VAL);
-		return -ENODEV;
-	}
-	/*
-	 * select Page 1 of spi_mem_page to enable access to
-	 * to registers from address 0x00 to 0x7F.
-	 */
-	ret = regmap_write_bits(regmap, BME680_REG_STATUS,
-				BME680_SPI_MEM_PAGE_BIT,
-				BME680_SPI_MEM_PAGE_1_VAL);
-	if (ret < 0) {
-		dev_err(&spi->dev, "failed to set page 1 of spi_mem_page\n");
-		return ret;
-	}
-
 	return bme680_core_probe(&spi->dev, regmap, id->name);
 }