mtd: rawnand: stm32_fmc2: get resources from parent node

FMC2 EBI support has been added. Common resources (registers base
address and clock) can now be shared between the 2 drivers using
"st,stm32mp1-fmc2-nfc" compatible string. It means that the
common resources should now be found in the parent device when EBI
node is available.

Signed-off-by: Christophe Kerello <[email protected]>
Signed-off-by: Miquel Raynal <[email protected]>
Link: https://lore.kernel.org/linux-mtd/[email protected]

Author: Christophe Kerello

drivers/mtd/nand/raw/Kconfig

@@ -415,8 +415,7 @@ config MTD_NAND_TEGRA
 config MTD_NAND_STM32_FMC2
 	tristate "Support for NAND controller on STM32MP SoCs"
 	depends on MACH_STM32MP157 || COMPILE_TEST
-	select REGMAP
-	select REGMAP_MMIO
+	select MFD_SYSCON
 	help
 	  Enables support for NAND Flash chips on SoCs containing the FMC2
 	  NAND controller. This controller is found on STM32MP SoCs.

drivers/mtd/nand/raw/stm32_fmc2_nand.c

@@ -11,8 +11,10 @@
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/iopoll.h>
+#include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/mtd/rawnand.h>
+#include <linux/of_address.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
@@ -204,16 +206,6 @@
 #define FMC2_BCHDSR4_EBP7		GENMASK(12, 0)
 #define FMC2_BCHDSR4_EBP8		GENMASK(28, 16)
 
-/* Regmap registers configuration */
-#define FMC2_MAX_REGISTER		0x3fc
-
-static const struct regmap_config stm32_fmc2_regmap_cfg = {
-	.reg_bits = 32,
-	.val_bits = 32,
-	.reg_stride = sizeof(u32),
-	.max_register = FMC2_MAX_REGISTER,
-};
-
 enum stm32_fmc2_ecc {
 	FMC2_ECC_HAM = 1,
 	FMC2_ECC_BCH4 = 4,
@@ -253,6 +245,7 @@ struct stm32_fmc2_nfc {
 	struct nand_controller base;
 	struct stm32_fmc2_nand nand;
 	struct device *dev;
+	struct device *cdev;
 	struct regmap *regmap;
 	void __iomem *data_base[FMC2_MAX_CE];
 	void __iomem *cmd_base[FMC2_MAX_CE];
@@ -1384,8 +1377,9 @@ static void stm32_fmc2_nfc_init(struct stm32_fmc2_nfc *nfc)
 	pcr |= FIELD_PREP(FMC2_PCR_TAR, FMC2_PCR_TAR_DEFAULT);
 
 	/* Enable FMC2 controller */
-	regmap_update_bits(nfc->regmap, FMC2_BCR1,
-			   FMC2_BCR1_FMC2EN, FMC2_BCR1_FMC2EN);
+	if (nfc->dev == nfc->cdev)
+		regmap_update_bits(nfc->regmap, FMC2_BCR1,
+				   FMC2_BCR1_FMC2EN, FMC2_BCR1_FMC2EN);
 
 	regmap_write(nfc->regmap, FMC2_PCR, pcr);
 	regmap_write(nfc->regmap, FMC2_PMEM, FMC2_PMEM_DEFAULT);
@@ -1815,6 +1809,33 @@ static int stm32_fmc2_nfc_parse_dt(struct stm32_fmc2_nfc *nfc)
 	return ret;
 }
 
+static int stm32_fmc2_nfc_set_cdev(struct stm32_fmc2_nfc *nfc)
+{
+	struct device *dev = nfc->dev;
+	bool ebi_found = false;
+
+	if (dev->parent && of_device_is_compatible(dev->parent->of_node,
+						   "st,stm32mp1-fmc2-ebi"))
+		ebi_found = true;
+
+	if (of_device_is_compatible(dev->of_node, "st,stm32mp1-fmc2-nfc")) {
+		if (ebi_found) {
+			nfc->cdev = dev->parent;
+
+			return 0;
+		}
+
+		return -EINVAL;
+	}
+
+	if (ebi_found)
+		return -EINVAL;
+
+	nfc->cdev = dev;
+
+	return 0;
+}
+
 static int stm32_fmc2_nfc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -1824,8 +1845,9 @@ static int stm32_fmc2_nfc_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct mtd_info *mtd;
 	struct nand_chip *chip;
-	void __iomem *mmio;
+	struct resource cres;
 	int chip_cs, mem_region, ret, irq;
+	int start_region = 0;
 
 	nfc = devm_kzalloc(dev, sizeof(*nfc), GFP_KERNEL);
 	if (!nfc)
@@ -1835,22 +1857,28 @@ static int stm32_fmc2_nfc_probe(struct platform_device *pdev)
 	nand_controller_init(&nfc->base);
 	nfc->base.ops = &stm32_fmc2_nfc_controller_ops;
 
+	ret = stm32_fmc2_nfc_set_cdev(nfc);
+	if (ret)
+		return ret;
+
 	ret = stm32_fmc2_nfc_parse_dt(nfc);
 	if (ret)
 		return ret;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	mmio = devm_ioremap_resource(dev, res);
-	if (IS_ERR(mmio))
-		return PTR_ERR(mmio);
+	ret = of_address_to_resource(nfc->cdev->of_node, 0, &cres);
+	if (ret)
+		return ret;
+
+	nfc->io_phys_addr = cres.start;
 
-	nfc->regmap = devm_regmap_init_mmio(dev, mmio, &stm32_fmc2_regmap_cfg);
+	nfc->regmap = device_node_to_regmap(nfc->cdev->of_node);
 	if (IS_ERR(nfc->regmap))
 		return PTR_ERR(nfc->regmap);
 
-	nfc->io_phys_addr = res->start;
+	if (nfc->dev == nfc->cdev)
+		start_region = 1;
 
-	for (chip_cs = 0, mem_region = 1; chip_cs < FMC2_MAX_CE;
+	for (chip_cs = 0, mem_region = start_region; chip_cs < FMC2_MAX_CE;
 	     chip_cs++, mem_region += 3) {
 		if (!(nfc->cs_assigned & BIT(chip_cs)))
 			continue;
@@ -1888,7 +1916,7 @@ static int stm32_fmc2_nfc_probe(struct platform_device *pdev)
 
 	init_completion(&nfc->complete);
 
-	nfc->clk = devm_clk_get(dev, NULL);
+	nfc->clk = devm_clk_get(nfc->cdev, NULL);
 	if (IS_ERR(nfc->clk))
 		return PTR_ERR(nfc->clk);
 
@@ -2029,6 +2057,7 @@ static SIMPLE_DEV_PM_OPS(stm32_fmc2_nfc_pm_ops, stm32_fmc2_nfc_suspend,
 
 static const struct of_device_id stm32_fmc2_nfc_match[] = {
 	{.compatible = "st,stm32mp15-fmc2"},
+	{.compatible = "st,stm32mp1-fmc2-nfc"},
 	{}
 };
 MODULE_DEVICE_TABLE(of, stm32_fmc2_nfc_match);