Merge tag 'iio-fixes-for-5.4a' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-linus

Jonathan writes:

First set of IIO fixes for the 5.4 cycle.

* adis16400
  - Make sure to free memory on a few failure paths.
* adxl372
  - Fix wrong fifo depth
  - Fix wrong indexing of data from the fifo.
  - Perform a reset at startup to avoid a problem with inconsistent state.
* axp288
  - This is a fix for a fix.  The original fix made sure we kept the
    configuration from some firmwares to preserve a bias current.
    Unfortunately it appears the previous behaviour was working around
    a buggy firmware by overwriting the wrong value it had.  Hence
    a regression was seen.
* bmc150
  - Fix the centre temperature.  This was due to an error in one of the
    datasheets.
* hx711
  - Fix an issue where a badly timed interrupt could lead to a control
    line being high long enough to put the device into a low power state.
* meson_sar_adc
  - Fix a case where the irq was enabled before everything it uses was
    allocated.
* st_lsm6dsx
  - Ensure we don't set the sensor sensitivity to 0 as it will force
    all readings to 0.
  - Fix a wait time for the slave i2c controller when the accelerometer
    is not enabled.
* stm32-adc
  - Precursor for fix. Move a set of register definitions to a header.
  - Fix a race when several ADCs are in use with some using interrupts
    to control the dataflow and some using DMA.
* vcnl4000
  - Fix a garbage of_match_table in which a string was passed instead
    of the intended enum.

* tag 'iio-fixes-for-5.4a' of https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
  iio: Fix an undefied reference error in noa1305_probe
  iio: light: opt3001: fix mutex unlock race
  iio: adc: ad799x: fix probe error handling
  iio: light: add missing vcnl4040 of_compatible
  iio: light: fix vcnl4000 devicetree hooks
  iio: imu: st_lsm6dsx: fix waitime for st_lsm6dsx i2c controller
  iio: adc: axp288: Override TS pin bias current for some models
  iio: imu: adis16400: fix memory leak
  iio: imu: adis16400: release allocated memory on failure
  iio: adc: stm32-adc: fix a race when using several adcs with dma and irq
  iio: adc: stm32-adc: move registers definitions
  iio: accel: adxl372: Perform a reset at start up
  iio: accel: adxl372: Fix push to buffers lost samples
  iio: accel: adxl372: Fix/remove limitation for FIFO samples
  iio: adc: hx711: fix bug in sampling of data
  iio: fix center temperature of bmc150-accel-core
  iio: imu: st_lsm6dsx: forbid 0 sensor sensitivity
  iio: adc: meson_saradc: Fix memory allocation order

1 files changed, 40 insertions, 30 deletions

diff --git a/drivers/iio/adc/stm32-adc-core.c b/drivers/iio/adc/stm32-adc-core.c
index 9b85fefc0a96..93a096a91f8c 100644
--- a/drivers/iio/adc/stm32-adc-core.c
+++ b/drivers/iio/adc/stm32-adc-core.c
@@ -24,33 +24,6 @@
 
 #include "stm32-adc-core.h"
 
-/* STM32F4 - common registers for all ADC instances: 1, 2 & 3 */
-#define STM32F4_ADC_CSR			(STM32_ADCX_COMN_OFFSET + 0x00)
-#define STM32F4_ADC_CCR			(STM32_ADCX_COMN_OFFSET + 0x04)
-
-/* STM32F4_ADC_CSR - bit fields */
-#define STM32F4_EOC3			BIT(17)
-#define STM32F4_EOC2			BIT(9)
-#define STM32F4_EOC1			BIT(1)
-
-/* STM32F4_ADC_CCR - bit fields */
-#define STM32F4_ADC_ADCPRE_SHIFT	16
-#define STM32F4_ADC_ADCPRE_MASK		GENMASK(17, 16)
-
-/* STM32H7 - common registers for all ADC instances */
-#define STM32H7_ADC_CSR			(STM32_ADCX_COMN_OFFSET + 0x00)
-#define STM32H7_ADC_CCR			(STM32_ADCX_COMN_OFFSET + 0x08)
-
-/* STM32H7_ADC_CSR - bit fields */
-#define STM32H7_EOC_SLV			BIT(18)
-#define STM32H7_EOC_MST			BIT(2)
-
-/* STM32H7_ADC_CCR - bit fields */
-#define STM32H7_PRESC_SHIFT		18
-#define STM32H7_PRESC_MASK		GENMASK(21, 18)
-#define STM32H7_CKMODE_SHIFT		16
-#define STM32H7_CKMODE_MASK		GENMASK(17, 16)
-
 #define STM32_ADC_CORE_SLEEP_DELAY_MS	2000
 
 /* SYSCFG registers */
@@ -71,6 +44,8 @@
  * @eoc1:	adc1 end of conversion flag in @csr
  * @eoc2:	adc2 end of conversion flag in @csr
  * @eoc3:	adc3 end of conversion flag in @csr
+ * @ier:	interrupt enable register offset for each adc
+ * @eocie_msk:	end of conversion interrupt enable mask in @ier
  */
 struct stm32_adc_common_regs {
 	u32 csr;
@@ -78,6 +53,8 @@ struct stm32_adc_common_regs {
 	u32 eoc1_msk;
 	u32 eoc2_msk;
 	u32 eoc3_msk;
+	u32 ier;
+	u32 eocie_msk;
 };
 
 struct stm32_adc_priv;
@@ -303,6 +280,8 @@ static const struct stm32_adc_common_regs stm32f4_adc_common_regs = {
 	.eoc1_msk = STM32F4_EOC1,
 	.eoc2_msk = STM32F4_EOC2,
 	.eoc3_msk = STM32F4_EOC3,
+	.ier = STM32F4_ADC_CR1,
+	.eocie_msk = STM32F4_EOCIE,
 };
 
 /* STM32H7 common registers definitions */
@@ -311,8 +290,24 @@ static const struct stm32_adc_common_regs stm32h7_adc_common_regs = {
 	.ccr = STM32H7_ADC_CCR,
 	.eoc1_msk = STM32H7_EOC_MST,
 	.eoc2_msk = STM32H7_EOC_SLV,
+	.ier = STM32H7_ADC_IER,
+	.eocie_msk = STM32H7_EOCIE,
+};
+
+static const unsigned int stm32_adc_offset[STM32_ADC_MAX_ADCS] = {
+	0, STM32_ADC_OFFSET, STM32_ADC_OFFSET * 2,
 };
 
+static unsigned int stm32_adc_eoc_enabled(struct stm32_adc_priv *priv,
+					  unsigned int adc)
+{
+	u32 ier, offset = stm32_adc_offset[adc];
+
+	ier = readl_relaxed(priv->common.base + offset + priv->cfg->regs->ier);
+
+	return ier & priv->cfg->regs->eocie_msk;
+}
+
 /* ADC common interrupt for all instances */
 static void stm32_adc_irq_handler(struct irq_desc *desc)
 {
@@ -323,13 +318,28 @@ static void stm32_adc_irq_handler(struct irq_desc *desc)
 	chained_irq_enter(chip, desc);
 	status = readl_relaxed(priv->common.base + priv->cfg->regs->csr);
 
-	if (status & priv->cfg->regs->eoc1_msk)
+	/*
+	 * End of conversion may be handled by using IRQ or DMA. There may be a
+	 * race here when two conversions complete at the same time on several
+	 * ADCs. EOC may be read 'set' for several ADCs, with:
+	 * - an ADC configured to use DMA (EOC triggers the DMA request, and
+	 *   is then automatically cleared by DR read in hardware)
+	 * - an ADC configured to use IRQs (EOCIE bit is set. The handler must
+	 *   be called in this case)
+	 * So both EOC status bit in CSR and EOCIE control bit must be checked
+	 * before invoking the interrupt handler (e.g. call ISR only for
+	 * IRQ-enabled ADCs).
+	 */
+	if (status & priv->cfg->regs->eoc1_msk &&
+	    stm32_adc_eoc_enabled(priv, 0))
 		generic_handle_irq(irq_find_mapping(priv->domain, 0));
 
-	if (status & priv->cfg->regs->eoc2_msk)
+	if (status & priv->cfg->regs->eoc2_msk &&
+	    stm32_adc_eoc_enabled(priv, 1))
 		generic_handle_irq(irq_find_mapping(priv->domain, 1));
 
-	if (status & priv->cfg->regs->eoc3_msk)
+	if (status & priv->cfg->regs->eoc3_msk &&
+	    stm32_adc_eoc_enabled(priv, 2))
 		generic_handle_irq(irq_find_mapping(priv->domain, 2));
 
 	chained_irq_exit(chip, desc);