spi: spi-fsl-dspi: Add ACPI support

Currently fsl DSPI driver has support of DT only. Adding ACPI
support to the drive so that it can be used by UEFI firmware
boot in ACPI mode. This driver will be probed if any firmware
will expose HID "NXP0005" in DSDT table.

Signed-off-by: tanveer <tanveer.alam@puresoftware.com>
Signed-off-by: kuldip dwivedi <kuldip.dwivedi@puresoftware.com>

drivers/spi/spi-fsl-dspi.c

@@ -2,10 +2,12 @@
 //
 // Copyright 2013 Freescale Semiconductor, Inc.
 // Copyright 2020 NXP
+// Copyright 2020 Puresoftware Ltd.
 //
 // Freescale DSPI driver
 // This file contains a driver for the Freescale DSPI
 
+#include <linux/acpi.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/dmaengine.h>
@@ -1070,6 +1072,12 @@ static void dspi_cleanup(struct spi_device *spi)
 	kfree(chip);
 }
 
+static const struct acpi_device_id fsl_dspi_acpi_ids[] = {
+	{ "NXP0005", .driver_data = (kernel_ulong_t)&devtype_data[LS2085A], },
+	{},
+};
+MODULE_DEVICE_TABLE(acpi, fsl_dspi_acpi_ids);
+
 static const struct of_device_id fsl_dspi_dt_ids[] = {
 	{
 		.compatible = "fsl,vf610-dspi",
@@ -1272,6 +1280,7 @@ static int dspi_probe(struct platform_device *pdev)
 	struct resource *res;
 	void __iomem *base;
 	bool big_endian;
+	u32 clk_rate;
 
 	ctlr = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
 	if (!ctlr)
@@ -1300,20 +1309,41 @@ static int dspi_probe(struct platform_device *pdev)
 		big_endian = true;
 	} else {
 
-		ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
+		if (is_acpi_node(pdev->dev.fwnode))
+			ret = device_property_read_u32(&pdev->dev,
+					"spi-num-chipselects", &cs_num);
+		else
+			ret = of_property_read_u32(np,
+					"spi-num-chipselects", &cs_num);
 		if (ret < 0) {
 			dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
 			goto out_ctlr_put;
 		}
 		ctlr->num_chipselect = cs_num;
 
-		of_property_read_u32(np, "bus-num", &bus_num);
+		if (is_acpi_node(pdev->dev.fwnode)) {
+			ret = device_property_read_u32(&pdev->dev,
+							"bus-num", &bus_num);
+			if (ret < 0) {
+				dev_err(&pdev->dev, "can't get bus-num\n");
+				goto out_ctlr_put;
+			}
+		} else {
+			of_property_read_u32(np, "bus-num", &bus_num);
+		}
 		ctlr->bus_num = bus_num;
 
-		if (of_property_read_bool(np, "spi-slave"))
-			ctlr->slave = true;
+		if (!is_acpi_node(pdev->dev.fwnode)) {
+			if (of_property_read_bool(np, "spi-slave"))
+				ctlr->slave = true;
+		}
+
+		if (is_acpi_node(pdev->dev.fwnode))
+			dspi->devtype_data = device_get_match_data(&pdev->dev);
+		else
+			dspi->devtype_data =
+				of_device_get_match_data(&pdev->dev);
 
-		dspi->devtype_data = of_device_get_match_data(&pdev->dev);
 		if (!dspi->devtype_data) {
 			dev_err(&pdev->dev, "can't get devtype_data\n");
 			ret = -EFAULT;
@@ -1367,15 +1397,18 @@ static int dspi_probe(struct platform_device *pdev)
 		}
 	}
 
-	dspi->clk = devm_clk_get(&pdev->dev, "dspi");
-	if (IS_ERR(dspi->clk)) {
-		ret = PTR_ERR(dspi->clk);
-		dev_err(&pdev->dev, "unable to get clock\n");
-		goto out_ctlr_put;
+	if (!is_acpi_node(pdev->dev.fwnode)) {
+		dspi->clk = devm_clk_get(&pdev->dev, "dspi");
+		if (IS_ERR(dspi->clk)) {
+			ret = PTR_ERR(dspi->clk);
+			dev_err(&pdev->dev, "unable to get clock\n");
+			goto out_ctlr_put;
+		}
+
+		ret = clk_prepare_enable(dspi->clk);
+		if (ret)
+			goto out_ctlr_put;
 	}
-	ret = clk_prepare_enable(dspi->clk);
-	if (ret)
-		goto out_ctlr_put;
 
 	ret = dspi_init(dspi);
 	if (ret)
@@ -1408,8 +1441,21 @@ static int dspi_probe(struct platform_device *pdev)
 		}
 	}
 
-	ctlr->max_speed_hz =
-		clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor;
+	if (is_acpi_node(pdev->dev.fwnode)) {
+		ret = device_property_read_u32(&pdev->dev,
+					       "clock-frequency", &clk_rate);
+		if (ret < 0) {
+			dev_err(&pdev->dev, "can't get clock-frequency\n");
+			goto out_ctlr_put;
+		}
+
+		ctlr->max_speed_hz =
+			clk_rate / dspi->devtype_data->max_clock_factor;
+	} else {
+		clk_rate = clk_get_rate(dspi->clk);
+		ctlr->max_speed_hz =
+			clk_rate / dspi->devtype_data->max_clock_factor;
+	}
 
 	if (dspi->devtype_data->trans_mode != DSPI_DMA_MODE)
 		ctlr->ptp_sts_supported = true;
@@ -1465,13 +1511,14 @@ static void dspi_shutdown(struct platform_device *pdev)
 }
 
 static struct platform_driver fsl_dspi_driver = {
-	.driver.name		= DRIVER_NAME,
-	.driver.of_match_table	= fsl_dspi_dt_ids,
-	.driver.owner		= THIS_MODULE,
-	.driver.pm		= &dspi_pm,
-	.probe			= dspi_probe,
-	.remove			= dspi_remove,
-	.shutdown		= dspi_shutdown,
+	.driver.name			= DRIVER_NAME,
+	.driver.of_match_table		= fsl_dspi_dt_ids,
+	.driver.acpi_match_table	= ACPI_PTR(fsl_dspi_acpi_ids),
+	.driver.owner			= THIS_MODULE,
+	.driver.pm			= &dspi_pm,
+	.probe				= dspi_probe,
+	.remove				= dspi_remove,
+	.shutdown			= dspi_shutdown,
 };
 module_platform_driver(fsl_dspi_driver);