[PATCH v4 4/5] spi: cadence: Allow to read basic xSPI configuration from ACPI

[Witold Sadowski <wsadowski@xxxxxxxxxxx>]

From: Piyush Malgujar <pmalgujar@xxxxxxxxxxx>

These changes enables to read the configs from ACPI tables as required
for successful probing in ACPI uefi environment.
In case of ACPI disabled/dts based environment, it will continue to
read configs from dts as before

Signed-off-by: Piyush Malgujar <pmalgujar@xxxxxxxxxxx>
Signed-off-by: Witold Sadowski <wsadowski@xxxxxxxxxxx>
---
 drivers/spi/spi-cadence-xspi.c | 84 +++++++++++++++++++++++++++++++---
 1 file changed, 77 insertions(+), 7 deletions(-)

diff --git a/drivers/spi/spi-cadence-xspi.c b/drivers/spi/spi-cadence-xspi.c
index 4bfcfa2f8835..f6bae59b34e5 100644
--- a/drivers/spi/spi-cadence-xspi.c
+++ b/drivers/spi/spi-cadence-xspi.c
@@ -2,6 +2,7 @@
 // Cadence XSPI flash controller driver
 // Copyright (C) 2020-21 Cadence
 
+#include <linux/acpi.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/err.h>
@@ -14,6 +15,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/property.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/spi-mem.h>
 #include <linux/bitfield.h>
@@ -647,6 +649,67 @@ static int cdns_xspi_mem_op(struct cdns_xspi_dev *cdns_xspi,
 					   (dir != SPI_MEM_NO_DATA));
 }
 
+#ifdef CONFIG_ACPI
+static bool cdns_xspi_supports_op(struct spi_mem *mem,
+				  const struct spi_mem_op *op)
+{
+	struct spi_device *spi = mem->spi;
+	const union acpi_object *obj;
+	struct acpi_device *adev;
+
+	adev = ACPI_COMPANION(&spi->dev);
+
+	if (!acpi_dev_get_property(adev, "spi-tx-bus-width", ACPI_TYPE_INTEGER,
+				   &obj)) {
+		switch (obj->integer.value) {
+		case 1:
+			break;
+		case 2:
+			spi->mode |= SPI_TX_DUAL;
+			break;
+		case 4:
+			spi->mode |= SPI_TX_QUAD;
+			break;
+		case 8:
+			spi->mode |= SPI_TX_OCTAL;
+			break;
+		default:
+			dev_warn(&spi->dev,
+				 "spi-tx-bus-width %lld not supported\n",
+				 obj->integer.value);
+			break;
+		}
+	}
+
+	if (!acpi_dev_get_property(adev, "spi-rx-bus-width", ACPI_TYPE_INTEGER,
+				   &obj)) {
+		switch (obj->integer.value) {
+		case 1:
+			break;
+		case 2:
+			spi->mode |= SPI_RX_DUAL;
+			break;
+		case 4:
+			spi->mode |= SPI_RX_QUAD;
+			break;
+		case 8:
+			spi->mode |= SPI_RX_OCTAL;
+			break;
+		default:
+			dev_warn(&spi->dev,
+				 "spi-rx-bus-width %lld not supported\n",
+				 obj->integer.value);
+			break;
+		}
+	}
+
+	if (!spi_mem_default_supports_op(mem, op))
+		return false;
+
+	return true;
+}
+#endif
+
 static int cdns_xspi_mem_op_execute(struct spi_mem *mem,
 				    const struct spi_mem_op *op)
 {
@@ -670,6 +733,9 @@ static int cdns_xspi_adjust_mem_op_size(struct spi_mem *mem, struct spi_mem_op *
 }
 
 static const struct spi_controller_mem_ops cadence_xspi_mem_ops = {
+#ifdef CONFIG_ACPI
+	.supports_op = cdns_xspi_supports_op,
+#endif
 	.exec_op = cdns_xspi_mem_op_execute,
 	.adjust_op_size = cdns_xspi_adjust_mem_op_size,
 };
@@ -721,21 +787,20 @@ static irqreturn_t cdns_xspi_irq_handler(int this_irq, void *dev)
 
 static int cdns_xspi_of_get_plat_data(struct platform_device *pdev)
 {
-	struct device_node *node_prop = pdev->dev.of_node;
-	struct device_node *node_child;
+	struct fwnode_handle *fwnode_child;
 	unsigned int cs;
 
-	for_each_child_of_node(node_prop, node_child) {
-		if (!of_device_is_available(node_child))
+	device_for_each_child_node(&pdev->dev, fwnode_child) {
+		if (!fwnode_device_is_available(fwnode_child))
 			continue;
 
-		if (of_property_read_u32(node_child, "reg", &cs)) {
+		if (fwnode_property_read_u32(fwnode_child, "reg", &cs)) {
 			dev_err(&pdev->dev, "Couldn't get memory chip select\n");
-			of_node_put(node_child);
+			fwnode_handle_put(fwnode_child);
 			return -ENXIO;
 		} else if (cs >= CDNS_XSPI_MAX_BANKS) {
 			dev_err(&pdev->dev, "reg (cs) parameter value too large\n");
-			of_node_put(node_child);
+			fwnode_handle_put(fwnode_child);
 			return -ENXIO;
 		}
 	}
@@ -789,6 +854,11 @@ static int cdns_xspi_probe(struct platform_device *pdev)
 		SPI_MODE_0  | SPI_MODE_3;
 
 	drv_data = of_device_get_match_data(dev);
+	if (!drv_data) {
+		drv_data = acpi_device_get_match_data(dev);
+		if (!drv_data)
+			return -ENODEV;
+	}
 
 	host->mem_ops = &cadence_xspi_mem_ops;
 	host->dev.of_node = pdev->dev.of_node;
-- 
2.43.0