spi: Abstract access to chip selects

Merge series from Amit Kumar Mahapatra <amit.kumar-mahapatra@amd.com>:

In preparation for supporting devices with multiple chip selects add an
interface for accessing the chip selects via a function.

drivers/spi/spi.c

@@ -604,7 +604,7 @@ static void spi_dev_set_name(struct spi_device *spi)
 	}
 
 	dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->controller->dev),
-		     spi->chip_select);
+		     spi_get_chipselect(spi, 0));
 }
 
 static int spi_dev_check(struct device *dev, void *data)
@@ -613,7 +613,7 @@ static int spi_dev_check(struct device *dev, void *data)
 	struct spi_device *new_spi = data;
 
 	if (spi->controller == new_spi->controller &&
-	    spi->chip_select == new_spi->chip_select)
+	    spi_get_chipselect(spi, 0) == spi_get_chipselect(new_spi, 0))
 		return -EBUSY;
 	return 0;
 }
@@ -638,7 +638,7 @@ static int __spi_add_device(struct spi_device *spi)
 	status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check);
 	if (status) {
 		dev_err(dev, "chipselect %d already in use\n",
-				spi->chip_select);
+				spi_get_chipselect(spi, 0));
 		return status;
 	}
 
@@ -649,7 +649,7 @@ static int __spi_add_device(struct spi_device *spi)
 	}
 
 	if (ctlr->cs_gpiods)
-		spi->cs_gpiod = ctlr->cs_gpiods[spi->chip_select];
+		spi_set_csgpiod(spi, 0, ctlr->cs_gpiods[spi_get_chipselect(spi, 0)]);
 
 	/*
 	 * Drivers may modify this initial i/o setup, but will
@@ -692,8 +692,8 @@ int spi_add_device(struct spi_device *spi)
 	int status;
 
 	/* Chipselects are numbered 0..max; validate. */
-	if (spi->chip_select >= ctlr->num_chipselect) {
-		dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
+	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
+		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
 			ctlr->num_chipselect);
 		return -EINVAL;
 	}
@@ -714,8 +714,8 @@ static int spi_add_device_locked(struct spi_device *spi)
 	struct device *dev = ctlr->dev.parent;
 
 	/* Chipselects are numbered 0..max; validate. */
-	if (spi->chip_select >= ctlr->num_chipselect) {
-		dev_err(dev, "cs%d >= max %d\n", spi->chip_select,
+	if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) {
+		dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0),
 			ctlr->num_chipselect);
 		return -EINVAL;
 	}
@@ -761,7 +761,7 @@ struct spi_device *spi_new_device(struct spi_controller *ctlr,
 
 	WARN_ON(strlen(chip->modalias) >= sizeof(proxy->modalias));
 
-	proxy->chip_select = chip->chip_select;
+	spi_set_chipselect(proxy, 0, chip->chip_select);
 	proxy->max_speed_hz = chip->max_speed_hz;
 	proxy->mode = chip->mode;
 	proxy->irq = chip->irq;
@@ -970,24 +970,23 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
 	 * Avoid calling into the driver (or doing delays) if the chip select
 	 * isn't actually changing from the last time this was called.
 	 */
-	if (!force && ((enable && spi->controller->last_cs == spi->chip_select) ||
-				(!enable && spi->controller->last_cs != spi->chip_select)) &&
+	if (!force && ((enable && spi->controller->last_cs == spi_get_chipselect(spi, 0)) ||
+		       (!enable && spi->controller->last_cs != spi_get_chipselect(spi, 0))) &&
 	    (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH)))
 		return;
 
 	trace_spi_set_cs(spi, activate);
 
-	spi->controller->last_cs = enable ? spi->chip_select : -1;
+	spi->controller->last_cs = enable ? spi_get_chipselect(spi, 0) : -1;
 	spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH;
 
-	if ((spi->cs_gpiod || !spi->controller->set_cs_timing) && !activate) {
+	if ((spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) && !activate)
 		spi_delay_exec(&spi->cs_hold, NULL);
-	}
 
 	if (spi->mode & SPI_CS_HIGH)
 		enable = !enable;
 
-	if (spi->cs_gpiod) {
+	if (spi_get_csgpiod(spi, 0)) {
 		if (!(spi->mode & SPI_NO_CS)) {
 			/*
 			 * Historically ACPI has no means of the GPIO polarity and
@@ -1000,10 +999,10 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
 			 * into account.
 			 */
 			if (has_acpi_companion(&spi->dev))
-				gpiod_set_value_cansleep(spi->cs_gpiod, !enable);
+				gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), !enable);
 			else
 				/* Polarity handled by GPIO library */
-				gpiod_set_value_cansleep(spi->cs_gpiod, activate);
+				gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), activate);
 		}
 		/* Some SPI masters need both GPIO CS & slave_select */
 		if ((spi->controller->flags & SPI_MASTER_GPIO_SS) &&
@@ -1013,7 +1012,7 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force)
 		spi->controller->set_cs(spi, !enable);
 	}
 
-	if (spi->cs_gpiod || !spi->controller->set_cs_timing) {
+	if (spi_get_csgpiod(spi, 0) || !spi->controller->set_cs_timing) {
 		if (activate)
 			spi_delay_exec(&spi->cs_setup, NULL);
 		else
@@ -2319,7 +2318,7 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi,
 			nc, rc);
 		return rc;
 	}
-	spi->chip_select = value;
+	spi_set_chipselect(spi, 0, value);
 
 	/* Device speed */
 	if (!of_property_read_u32(nc, "spi-max-frequency", &value))
@@ -2438,7 +2437,7 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi,
 	strscpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias));
 
 	/* Use provided chip-select for ancillary device */
-	ancillary->chip_select = chip_select;
+	spi_set_chipselect(ancillary, 0, chip_select);
 
 	/* Take over SPI mode/speed from SPI main device */
 	ancillary->max_speed_hz = spi->max_speed_hz;
@@ -2685,7 +2684,7 @@ struct spi_device *acpi_spi_device_alloc(struct spi_controller *ctlr,
 	spi->mode		|= lookup.mode;
 	spi->irq		= lookup.irq;
 	spi->bits_per_word	= lookup.bits_per_word;
-	spi->chip_select	= lookup.chip_select;
+	spi_set_chipselect(spi, 0, lookup.chip_select);
 
 	return spi;
 }
@@ -3647,7 +3646,7 @@ static int spi_set_cs_timing(struct spi_device *spi)
 	struct device *parent = spi->controller->dev.parent;
 	int status = 0;
 
-	if (spi->controller->set_cs_timing && !spi->cs_gpiod) {
+	if (spi->controller->set_cs_timing && !spi_get_csgpiod(spi, 0)) {
 		if (spi->controller->auto_runtime_pm) {
 			status = pm_runtime_get_sync(parent);
 			if (status < 0) {
@@ -3852,7 +3851,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 	 * cs_change is set for each transfer.
 	 */
 	if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) ||
-					  spi->cs_gpiod)) {
+					  spi_get_csgpiod(spi, 0))) {
 		size_t maxsize;
 		int ret;
 

include/linux/spi/spi.h

@@ -263,6 +263,26 @@ static inline void *spi_get_drvdata(struct spi_device *spi)
 	return dev_get_drvdata(&spi->dev);
 }
 
+static inline u8 spi_get_chipselect(struct spi_device *spi, u8 idx)
+{
+	return spi->chip_select;
+}
+
+static inline void spi_set_chipselect(struct spi_device *spi, u8 idx, u8 chipselect)
+{
+	spi->chip_select = chipselect;
+}
+
+static inline struct gpio_desc *spi_get_csgpiod(struct spi_device *spi, u8 idx)
+{
+	return spi->cs_gpiod;
+}
+
+static inline void spi_set_csgpiod(struct spi_device *spi, u8 idx, struct gpio_desc *csgpiod)
+{
+	spi->cs_gpiod = csgpiod;
+}
+
 struct spi_message;
 
 /**