[MTD] [NAND] FSL UPM NAND driver

This is very simple driver, NAND is connected through localbus,
and User-Programmable Machine is doing various adjustments to
speak NAND. No special efforts needed to do read and write cycles,
though to control ALE and CLE phases, we ask UPM to generate exact
pre-programmed signals on the localbus lines.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

drivers/mtd/nand/Kconfig

@@ -337,4 +337,12 @@ config MTD_NAND_FSL_ELBC
 	  Enabling this option will enable you to use this to control
 	  external NAND devices.
 
+config MTD_NAND_FSL_UPM
+	tristate "Support for NAND on Freescale UPM"
+	depends on MTD_NAND && OF_GPIO && (PPC_83xx || PPC_85xx)
+	select FSL_LBC
+	help
+	  Enables support for NAND Flash chips wired onto Freescale PowerPC
+	  processor localbus with User-Programmable Machine support.
+
 endif # MTD_NAND

drivers/mtd/nand/Makefile

@@ -33,5 +33,6 @@ obj-$(CONFIG_MTD_ALAUDA)		+= alauda.o
 obj-$(CONFIG_MTD_NAND_PASEMI)		+= pasemi_nand.o
 obj-$(CONFIG_MTD_NAND_ORION)		+= orion_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_ELBC)		+= fsl_elbc_nand.o
+obj-$(CONFIG_MTD_NAND_FSL_UPM)		+= fsl_upm.o
 
 nand-objs := nand_base.o nand_bbt.o

drivers/mtd/nand/fsl_upm.c

@@ -0,0 +1,291 @@
+/*
+ * Freescale UPM NAND driver.
+ *
+ * Copyright © 2007-2008  MontaVista Software, Inc.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/mtd.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
+#include <linux/io.h>
+#include <asm/fsl_lbc.h>
+
+struct fsl_upm_nand {
+	struct device *dev;
+	struct mtd_info mtd;
+	struct nand_chip chip;
+	int last_ctrl;
+#ifdef CONFIG_MTD_PARTITIONS
+	struct mtd_partition *parts;
+#endif
+
+	struct fsl_upm upm;
+	uint8_t upm_addr_offset;
+	uint8_t upm_cmd_offset;
+	void __iomem *io_base;
+	int rnb_gpio;
+	const uint32_t *wait_pattern;
+	const uint32_t *wait_write;
+	int chip_delay;
+};
+
+#define to_fsl_upm_nand(mtd) container_of(mtd, struct fsl_upm_nand, mtd)
+
+static int fun_chip_ready(struct mtd_info *mtd)
+{
+	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
+
+	if (gpio_get_value(fun->rnb_gpio))
+		return 1;
+
+	dev_vdbg(fun->dev, "busy\n");
+	return 0;
+}
+
+static void fun_wait_rnb(struct fsl_upm_nand *fun)
+{
+	int cnt = 1000000;
+
+	if (fun->rnb_gpio >= 0) {
+		while (--cnt && !fun_chip_ready(&fun->mtd))
+			cpu_relax();
+	}
+
+	if (!cnt)
+		dev_err(fun->dev, "tired waiting for RNB\n");
+}
+
+static void fun_cmd_ctrl(struct mtd_info *mtd, int cmd, unsigned int ctrl)
+{
+	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
+
+	if (!(ctrl & fun->last_ctrl)) {
+		fsl_upm_end_pattern(&fun->upm);
+
+		if (cmd == NAND_CMD_NONE)
+			return;
+
+		fun->last_ctrl = ctrl & (NAND_ALE | NAND_CLE);
+	}
+
+	if (ctrl & NAND_CTRL_CHANGE) {
+		if (ctrl & NAND_ALE)
+			fsl_upm_start_pattern(&fun->upm, fun->upm_addr_offset);
+		else if (ctrl & NAND_CLE)
+			fsl_upm_start_pattern(&fun->upm, fun->upm_cmd_offset);
+	}
+
+	fsl_upm_run_pattern(&fun->upm, fun->io_base, cmd);
+
+	if (fun->wait_pattern)
+		fun_wait_rnb(fun);
+}
+
+static uint8_t fun_read_byte(struct mtd_info *mtd)
+{
+	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
+
+	return in_8(fun->chip.IO_ADDR_R);
+}
+
+static void fun_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
+{
+	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
+	int i;
+
+	for (i = 0; i < len; i++)
+		buf[i] = in_8(fun->chip.IO_ADDR_R);
+}
+
+static void fun_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
+{
+	struct fsl_upm_nand *fun = to_fsl_upm_nand(mtd);
+	int i;
+
+	for (i = 0; i < len; i++) {
+		out_8(fun->chip.IO_ADDR_W, buf[i]);
+		if (fun->wait_write)
+			fun_wait_rnb(fun);
+	}
+}
+
+static int __devinit fun_chip_init(struct fsl_upm_nand *fun)
+{
+	int ret;
+#ifdef CONFIG_MTD_PARTITIONS
+	static const char *part_types[] = { "cmdlinepart", NULL, };
+#endif
+
+	fun->chip.IO_ADDR_R = fun->io_base;
+	fun->chip.IO_ADDR_W = fun->io_base;
+	fun->chip.cmd_ctrl = fun_cmd_ctrl;
+	fun->chip.chip_delay = fun->chip_delay;
+	fun->chip.read_byte = fun_read_byte;
+	fun->chip.read_buf = fun_read_buf;
+	fun->chip.write_buf = fun_write_buf;
+	fun->chip.ecc.mode = NAND_ECC_SOFT;
+
+	if (fun->rnb_gpio >= 0)
+		fun->chip.dev_ready = fun_chip_ready;
+
+	fun->mtd.priv = &fun->chip;
+	fun->mtd.owner = THIS_MODULE;
+
+	ret = nand_scan(&fun->mtd, 1);
+	if (ret)
+		return ret;
+
+	fun->mtd.name = fun->dev->bus_id;
+
+#ifdef CONFIG_MTD_PARTITIONS
+	ret = parse_mtd_partitions(&fun->mtd, part_types, &fun->parts, 0);
+	if (ret > 0)
+		return add_mtd_partitions(&fun->mtd, fun->parts, ret);
+#endif
+	return add_mtd_device(&fun->mtd);
+}
+
+static int __devinit fun_probe(struct of_device *ofdev,
+			       const struct of_device_id *ofid)
+{
+	struct fsl_upm_nand *fun;
+	struct resource io_res;
+	const uint32_t *prop;
+	int ret;
+	int size;
+
+	fun = kzalloc(sizeof(*fun), GFP_KERNEL);
+	if (!fun)
+		return -ENOMEM;
+
+	ret = of_address_to_resource(ofdev->node, 0, &io_res);
+	if (ret) {
+		dev_err(&ofdev->dev, "can't get IO base\n");
+		goto err1;
+	}
+
+	ret = fsl_upm_find(io_res.start, &fun->upm);
+	if (ret) {
+		dev_err(&ofdev->dev, "can't find UPM\n");
+		goto err1;
+	}
+
+	prop = of_get_property(ofdev->node, "fsl,upm-addr-offset", &size);
+	if (!prop || size != sizeof(uint32_t)) {
+		dev_err(&ofdev->dev, "can't get UPM address offset\n");
+		ret = -EINVAL;
+		goto err2;
+	}
+	fun->upm_addr_offset = *prop;
+
+	prop = of_get_property(ofdev->node, "fsl,upm-cmd-offset", &size);
+	if (!prop || size != sizeof(uint32_t)) {
+		dev_err(&ofdev->dev, "can't get UPM command offset\n");
+		ret = -EINVAL;
+		goto err2;
+	}
+	fun->upm_cmd_offset = *prop;
+
+	fun->rnb_gpio = of_get_gpio(ofdev->node, 0);
+	if (fun->rnb_gpio >= 0) {
+		ret = gpio_request(fun->rnb_gpio, ofdev->dev.bus_id);
+		if (ret) {
+			dev_err(&ofdev->dev, "can't request RNB gpio\n");
+			goto err2;
+		}
+		gpio_direction_input(fun->rnb_gpio);
+	} else if (fun->rnb_gpio == -EINVAL) {
+		dev_err(&ofdev->dev, "specified RNB gpio is invalid\n");
+		goto err2;
+	}
+
+	fun->io_base = devm_ioremap_nocache(&ofdev->dev, io_res.start,
+					  io_res.end - io_res.start + 1);
+	if (!fun->io_base) {
+		ret = -ENOMEM;
+		goto err2;
+	}
+
+	fun->dev = &ofdev->dev;
+	fun->last_ctrl = NAND_CLE;
+	fun->wait_pattern = of_get_property(ofdev->node, "fsl,wait-pattern",
+					    NULL);
+	fun->wait_write = of_get_property(ofdev->node, "fsl,wait-write", NULL);
+
+	prop = of_get_property(ofdev->node, "chip-delay", NULL);
+	if (prop)
+		fun->chip_delay = *prop;
+	else
+		fun->chip_delay = 50;
+
+	ret = fun_chip_init(fun);
+	if (ret)
+		goto err2;
+
+	dev_set_drvdata(&ofdev->dev, fun);
+
+	return 0;
+err2:
+	if (fun->rnb_gpio >= 0)
+		gpio_free(fun->rnb_gpio);
+err1:
+	kfree(fun);
+
+	return ret;
+}
+
+static int __devexit fun_remove(struct of_device *ofdev)
+{
+	struct fsl_upm_nand *fun = dev_get_drvdata(&ofdev->dev);
+
+	nand_release(&fun->mtd);
+
+	if (fun->rnb_gpio >= 0)
+		gpio_free(fun->rnb_gpio);
+
+	kfree(fun);
+
+	return 0;
+}
+
+static struct of_device_id of_fun_match[] = {
+	{ .compatible = "fsl,upm-nand" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_fun_match);
+
+static struct of_platform_driver of_fun_driver = {
+	.name		= "fsl,upm-nand",
+	.match_table	= of_fun_match,
+	.probe		= fun_probe,
+	.remove		= __devexit_p(fun_remove),
+};
+
+static int __init fun_module_init(void)
+{
+	return of_register_platform_driver(&of_fun_driver);
+}
+module_init(fun_module_init);
+
+static void __exit fun_module_exit(void)
+{
+	of_unregister_platform_driver(&of_fun_driver);
+}
+module_exit(fun_module_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Anton Vorontsov <avorontsov@ru.mvista.com>");
+MODULE_DESCRIPTION("Driver for NAND chips working through Freescale "
+		   "LocalBus User-Programmable Machine");