[PATCH] Add devicetree support to m25p80 driver

[Michal Vanka]

The following patch adds support for devicetree to m25p80 driver.
Note that for jedec chips the chip identification was simplified.
The particular chip is identified by jedec_id only.
Tested on custom Altera Nios2 system.

Signed-off-by: Michal Vanka <mv at vanka.net>

diff --git a/Documentation/devicetree/bindings/mtd/m25pxx.txt 
b/Documentation/devicetree/bindings/mtd/m25pxx.txt
index e69de29..c454a5b 100644
--- a/Documentation/devicetree/bindings/mtd/m25pxx.txt
+++ b/Documentation/devicetree/bindings/mtd/m25pxx.txt
@@ -0,0 +1,39 @@
+* M25PXX Serial Flash
+
+Required properties:
+- compatible : For jedec part should be "generic,m25pxx"
+               For non-jedec part should be one of the following:
+		"catalyst,cat25c11"
+		"catalyst,cat25c03"
+		"catalyst,cat25c09"
+		"catalyst,cat25c17"
+		"catalyst,cat25128"
+		"stmicro,m25p05-nonjedec"
+		"stmicro,m25p10-nonjedec"
+		"stmicro,m25p20-nonjedec"
+		"stmicro,m25p40-nonjedec"
+		"stmicro,m25p80-nonjedec"
+		"stmicro,m25p16-nonjedec"
+		"stmicro,m25p32-nonjedec"
+		"stmicro,m25p64-nonjedec"
+		"stmicro,m25p128-nonjedec"
+
+- spi-max-frequency : Maximum operating frequency for the given chip.
+- reg : Chipselect bit number on gpios chipselect port.
+
+Example: S25FL064K hooked to tinyspi controller:
+
+tiny_spi_2: spi at 0x4000 {
+	compatible = "opencores,tiny-spi-1.0", "opencores,tiny-spi-rtlsvn2";
+	reg = < 0x00004000 0x00000020 >;
+	interrupt-parent = < &cpu >;
+	interrupts = < 5 >;
+	clock-frequency = < 100000000 >;
+	baud-width = < 8 >;	/* BAUD_WIDTH type NUMBER */
+	gpios = < &spi2_cs 0 0 >;
+	spansion_flash: m25pxx at 0 {
+		compatible = "generic,m25pxx";
+		spi-max-frequency = < 20000000 >;
+		reg = <0>;
+	};
+};
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 5d0d68c..1db2c63 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -744,6 +744,29 @@ static const struct spi_device_id m25p_ids[] = {
  };
  MODULE_DEVICE_TABLE(spi, m25p_ids);

+#ifdef CONFIG_OF
+static const struct of_device_id m25pxx_dt_ids[] = {
+	{ .compatible = "generic,m25pxx", },
+	{ .compatible = "catalyst,cat25c11", },
+	{ .compatible = "catalyst,cat25c03", },
+	{ .compatible = "catalyst,cat25c09", },
+	{ .compatible = "catalyst,cat25c17", },
+	{ .compatible = "catalyst,cat25128", },
+	{ .compatible = "stmicro,m25p05-nonjedec", },
+	{ .compatible = "stmicro,m25p10-nonjedec", },
+	{ .compatible = "stmicro,m25p20-nonjedec", },
+	{ .compatible = "stmicro,m25p40-nonjedec", },
+	{ .compatible = "stmicro,m25p80-nonjedec", },
+	{ .compatible = "stmicro,m25p16-nonjedec", },
+	{ .compatible = "stmicro,m25p32-nonjedec", },
+	{ .compatible = "stmicro,m25p64-nonjedec", },
+	{ .compatible = "stmicro,m25p128-nonjedec", },
+	{ /* sentinel */ }
+};
+#else
+#define m25pxx_dt_ids NULL
+#endif
+
  static const struct spi_device_id *__devinit jedec_probe(struct 
spi_device *spi)
  {
  	int			tmp;
@@ -798,7 +821,7 @@ static int __devinit m25p_probe(struct spi_device *spi)
  	unsigned			i;
  	struct mtd_part_parser_data	ppdata;

-#ifdef CONFIG_MTD_OF_PARTS
+#if defined(CONFIG_MTD_OF_PARTS) || defined(CONFIG_OF)
  	if (!of_device_is_available(spi->dev.of_node))
  		return -ENODEV;
  #endif
@@ -825,27 +848,39 @@ static int __devinit m25p_probe(struct spi_device 
*spi)
  			dev_warn(&spi->dev, "unrecognized id %s\n", data->type);
  	}

-	info = (void *)id->driver_data;
-
-	if (info->jedec_id) {
-		const struct spi_device_id *jid;
-
-		jid = jedec_probe(spi);
-		if (IS_ERR(jid)) {
-			return PTR_ERR(jid);
-		} else if (jid != id) {
-			/*
-			 * JEDEC knows better, so overwrite platform ID. We
-			 * can't trust partitions any longer, but we'll let
-			 * mtd apply them anyway, since some partitions may be
-			 * marked read-only, and we don't want to lose that
-			 * information, even if it's not 100% accurate.
-			 */
-			dev_warn(&spi->dev, "found %s, expected %s\n",
-				 jid->name, id->name);
-			id = jid;
-			info = (void *)jid->driver_data;
+	if (id) {
+		info = (void *)id->driver_data;
+		if (info->jedec_id) {
+			const struct spi_device_id *jid;
+
+			jid = jedec_probe(spi);
+			if (IS_ERR(jid)) {
+				return PTR_ERR(jid);
+			} else if (jid != id) {
+				/*
+				 * JEDEC knows better, so overwrite platform ID.
+				 * We can't trust partitions any longer, but
+				 * we'll let mtd apply them anyway, since some
+				 * partitions may be marked read-only,
+				 * and we don't want to lose that information,
+				 * even if it's not 100% accurate.
+				 */
+				dev_warn(&spi->dev, "found %s, expected %s\n",
+					 jid->name, id->name);
+				id = jid;
+				info = (void *)jid->driver_data;
+			}
  		}
+	} else {
+		/*
+		 * No id -> we have been most likely configured
+		 * by devicetree "generic,m25pxx" record.
+		 */
+		id = jedec_probe(spi);
+		if (IS_ERR(id))
+			return PTR_ERR(id);
+
+		info = (void *)id->driver_data;
  	}

  	flash = kzalloc(sizeof *flash, GFP_KERNEL);
@@ -968,6 +1003,7 @@ static struct spi_driver m25p80_driver = {
  	.driver = {
  		.name	= "m25p80",
  		.owner	= THIS_MODULE,
+		.of_match_table = m25pxx_dt_ids,
  	},
  	.id_table	= m25p_ids,
  	.probe	= m25p_probe,