Merge tag 'staging-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging

Pull staging/IIO driver fixes from Greg KH:
 "Here are some staging and IIO driver fixes for 5.4-rc3.

  The "biggest" thing here is a removal of the fbtft device and flexfb
  code as they have been abandoned by their authors and are no longer
  needed for that hardware.

  Other than that, the usual amount of staging driver and iio driver
  fixes for reported issues, and some speakup sysfs file documentation,
  which has been long awaited for.

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

* tag 'staging-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (32 commits)
  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
  staging: vt6655: Fix memory leak in vt6655_probe
  staging: exfat: Use kvzalloc() instead of kzalloc() for exfat_sb_info
  Staging: fbtft: fix memory leak in fbtft_framebuffer_alloc
  staging: speakup: document sysfs attributes
  staging: rtl8188eu: fix HighestRate check in odm_ARFBRefresh_8188E()
  ...

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);