spi: Fixes for v5.9

A bunch of fixes that came in for SPI during the merge window, a bunch
 from ST and others for their controller, one from Lukas for a race
 between device addition and controller unregistration and one from fix
 from Geert for the DT bindings which unbreaks validation.
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Merge tag 'spi-fix-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A bunch of fixes that came in for SPI during the merge window.

  Some from ST and others for their controller, one from Lukas for a
  race between device addition and controller unregistration and one
  from fix from Geert for the DT bindings which unbreaks validation"

* tag 'spi-fix-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  dt-bindings: lpspi: Add missing boolean type for fsl,spi-only-use-cs1-sel
  spi: stm32: always perform registers configuration prior to transfer
  spi: stm32: fixes suspend/resume management
  spi: stm32: fix stm32_spi_prepare_mbr in case of odd clk_rate
  spi: stm32: fix fifo threshold level in case of short transfer
  spi: stm32h7: fix race condition at end of transfer
  spi: stm32: clear only asserted irq flags on interrupt
  spi: Prevent adding devices below an unregistering controller

Documentation/devicetree/bindings/spi/spi-fsl-lpspi.yaml

@@ -39,6 +39,7 @@ properties:
       spi common code does not support use of CS signals discontinuously.
       i.MX8DXL-EVK board only uses CS1 without using CS0. Therefore, add
       this property to re-config the chipselect value in the LPSPI driver.
+    type: boolean
 
 required:
   - compatible

drivers/spi/Kconfig

@@ -1017,4 +1017,7 @@ config SPI_SLAVE_SYSTEM_CONTROL
 
 endif # SPI_SLAVE
 
+config SPI_DYNAMIC
+	def_bool ACPI || OF_DYNAMIC || SPI_SLAVE
+
 endif # SPI

drivers/spi/spi-stm32.c

@@ -13,6 +13,7 @@
 #include <linux/iopoll.h>
 #include <linux/module.h>
 #include <linux/of_platform.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
 #include <linux/spi/spi.h>
@@ -441,7 +442,8 @@ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz,
 {
 	u32 div, mbrdiv;
 
-	div = DIV_ROUND_UP(spi->clk_rate, speed_hz);
+	/* Ensure spi->clk_rate is even */
+	div = DIV_ROUND_UP(spi->clk_rate & ~0x1, speed_hz);
 
 	/*
 	 * SPI framework set xfer->speed_hz to master->max_speed_hz if
@@ -467,20 +469,27 @@ static int stm32_spi_prepare_mbr(struct stm32_spi *spi, u32 speed_hz,
 /**
  * stm32h7_spi_prepare_fthlv - Determine FIFO threshold level
  * @spi: pointer to the spi controller data structure
+ * @xfer_len: length of the message to be transferred
  */
-static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi)
+static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi, u32 xfer_len)
 {
-	u32 fthlv, half_fifo;
+	u32 fthlv, half_fifo, packet;
 
 	/* data packet should not exceed 1/2 of fifo space */
 	half_fifo = (spi->fifo_size / 2);
 
-	if (spi->cur_bpw <= 8)
-		fthlv = half_fifo;
-	else if (spi->cur_bpw <= 16)
-		fthlv = half_fifo / 2;
+	/* data_packet should not exceed transfer length */
+	if (half_fifo > xfer_len)
+		packet = xfer_len;
 	else
-		fthlv = half_fifo / 4;
+		packet = half_fifo;
+
+	if (spi->cur_bpw <= 8)
+		fthlv = packet;
+	else if (spi->cur_bpw <= 16)
+		fthlv = packet / 2;
+	else
+		fthlv = packet / 4;
 
 	/* align packet size with data registers access */
 	if (spi->cur_bpw > 8)
@@ -488,6 +497,9 @@ static u32 stm32h7_spi_prepare_fthlv(struct stm32_spi *spi)
 	else
 		fthlv -= (fthlv % 4); /* multiple of 4 */
 
+	if (!fthlv)
+		fthlv = 1;
+
 	return fthlv;
 }
 
@@ -966,13 +978,13 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
 		if (!spi->cur_usedma && (spi->rx_buf && (spi->rx_len > 0)))
 			stm32h7_spi_read_rxfifo(spi, false);
 
-	writel_relaxed(mask, spi->base + STM32H7_SPI_IFCR);
+	writel_relaxed(sr & mask, spi->base + STM32H7_SPI_IFCR);
 
 	spin_unlock_irqrestore(&spi->lock, flags);
 
 	if (end) {
-		spi_finalize_current_transfer(master);
 		stm32h7_spi_disable(spi);
+		spi_finalize_current_transfer(master);
 	}
 
 	return IRQ_HANDLED;
@@ -1393,7 +1405,7 @@ static void stm32h7_spi_set_bpw(struct stm32_spi *spi)
 	cfg1_setb |= (bpw << STM32H7_SPI_CFG1_DSIZE_SHIFT) &
 		     STM32H7_SPI_CFG1_DSIZE;
 
-	spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi);
+	spi->cur_fthlv = stm32h7_spi_prepare_fthlv(spi, spi->cur_xferlen);
 	fthlv = spi->cur_fthlv - 1;
 
 	cfg1_clrb |= STM32H7_SPI_CFG1_FTHLV;
@@ -1585,39 +1597,33 @@ static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
 	unsigned long flags;
 	unsigned int comm_type;
 	int nb_words, ret = 0;
+	int mbr;
 
 	spin_lock_irqsave(&spi->lock, flags);
 
-	if (spi->cur_bpw != transfer->bits_per_word) {
-		spi->cur_bpw = transfer->bits_per_word;
-		spi->cfg->set_bpw(spi);
+	spi->cur_xferlen = transfer->len;
+
+	spi->cur_bpw = transfer->bits_per_word;
+	spi->cfg->set_bpw(spi);
+
+	/* Update spi->cur_speed with real clock speed */
+	mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz,
+				    spi->cfg->baud_rate_div_min,
+				    spi->cfg->baud_rate_div_max);
+	if (mbr < 0) {
+		ret = mbr;
+		goto out;
 	}
 
-	if (spi->cur_speed != transfer->speed_hz) {
-		int mbr;
-
-		/* Update spi->cur_speed with real clock speed */
-		mbr = stm32_spi_prepare_mbr(spi, transfer->speed_hz,
-					    spi->cfg->baud_rate_div_min,
-					    spi->cfg->baud_rate_div_max);
-		if (mbr < 0) {
-			ret = mbr;
-			goto out;
-		}
-
-		transfer->speed_hz = spi->cur_speed;
-		stm32_spi_set_mbr(spi, mbr);
-	}
+	transfer->speed_hz = spi->cur_speed;
+	stm32_spi_set_mbr(spi, mbr);
 
 	comm_type = stm32_spi_communication_type(spi_dev, transfer);
-	if (spi->cur_comm != comm_type) {
-		ret = spi->cfg->set_mode(spi, comm_type);
+	ret = spi->cfg->set_mode(spi, comm_type);
+	if (ret < 0)
+		goto out;
 
-		if (ret < 0)
-			goto out;
-
-		spi->cur_comm = comm_type;
-	}
+	spi->cur_comm = comm_type;
 
 	if (spi->cfg->set_data_idleness)
 		spi->cfg->set_data_idleness(spi, transfer->len);
@@ -1635,8 +1641,6 @@ static int stm32_spi_transfer_one_setup(struct stm32_spi *spi,
 			goto out;
 	}
 
-	spi->cur_xferlen = transfer->len;
-
 	dev_dbg(spi->dev, "transfer communication mode set to %d\n",
 		spi->cur_comm);
 	dev_dbg(spi->dev,
@@ -1996,6 +2000,8 @@ static int stm32_spi_remove(struct platform_device *pdev)
 
 	pm_runtime_disable(&pdev->dev);
 
+	pinctrl_pm_select_sleep_state(&pdev->dev);
+
 	return 0;
 }
 
@@ -2007,13 +2013,18 @@ static int stm32_spi_runtime_suspend(struct device *dev)
 
 	clk_disable_unprepare(spi->clk);
 
-	return 0;
+	return pinctrl_pm_select_sleep_state(dev);
 }
 
 static int stm32_spi_runtime_resume(struct device *dev)
 {
 	struct spi_master *master = dev_get_drvdata(dev);
 	struct stm32_spi *spi = spi_master_get_devdata(master);
+	int ret;
+
+	ret = pinctrl_pm_select_default_state(dev);
+	if (ret)
+		return ret;
 
 	return clk_prepare_enable(spi->clk);
 }
@@ -2043,10 +2054,23 @@ static int stm32_spi_resume(struct device *dev)
 		return ret;
 
 	ret = spi_master_resume(master);
-	if (ret)
+	if (ret) {
 		clk_disable_unprepare(spi->clk);
+		return ret;
+	}
 
-	return ret;
+	ret = pm_runtime_get_sync(dev);
+	if (ret) {
+		dev_err(dev, "Unable to power device:%d\n", ret);
+		return ret;
+	}
+
+	spi->cfg->config(spi);
+
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return 0;
 }
 #endif
 

drivers/spi/spi.c

@@ -475,6 +475,12 @@ static LIST_HEAD(spi_controller_list);
  */
 static DEFINE_MUTEX(board_lock);
 
+/*
+ * Prevents addition of devices with same chip select and
+ * addition of devices below an unregistering controller.
+ */
+static DEFINE_MUTEX(spi_add_lock);
+
 /**
  * spi_alloc_device - Allocate a new SPI device
  * @ctlr: Controller to which device is connected
@@ -554,7 +560,6 @@ static int spi_dev_check(struct device *dev, void *data)
  */
 int spi_add_device(struct spi_device *spi)
 {
-	static DEFINE_MUTEX(spi_add_lock);
 	struct spi_controller *ctlr = spi->controller;
 	struct device *dev = ctlr->dev.parent;
 	int status;
@@ -582,6 +587,13 @@ int spi_add_device(struct spi_device *spi)
 		goto done;
 	}
 
+	/* Controller may unregister concurrently */
+	if (IS_ENABLED(CONFIG_SPI_DYNAMIC) &&
+	    !device_is_registered(&ctlr->dev)) {
+		status = -ENODEV;
+		goto done;
+	}
+
 	/* Descriptors take precedence */
 	if (ctlr->cs_gpiods)
 		spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
@@ -2795,6 +2807,10 @@ void spi_unregister_controller(struct spi_controller *ctlr)
 	struct spi_controller *found;
 	int id = ctlr->bus_num;
 
+	/* Prevent addition of new devices, unregister existing ones */
+	if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
+		mutex_lock(&spi_add_lock);
+
 	device_for_each_child(&ctlr->dev, NULL, __unregister);
 
 	/* First make sure that this controller was ever added */
@@ -2815,6 +2831,9 @@ void spi_unregister_controller(struct spi_controller *ctlr)
 	if (found == ctlr)
 		idr_remove(&spi_master_idr, id);
 	mutex_unlock(&board_lock);
+
+	if (IS_ENABLED(CONFIG_SPI_DYNAMIC))
+		mutex_unlock(&spi_add_lock);
 }
 EXPORT_SYMBOL_GPL(spi_unregister_controller);