mtd: nand: Add OX820 NAND Support

Add NAND driver to support the Oxford Semiconductor OX820 NAND Controller.
This is a simple memory mapped NAND controller with single chip select and
software ECC.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>

diff --git a/Documentation/devicetree/bindings/mtd/oxnas-nand.txt b/Documentation/devicetree/bindings/mtd/oxnas-nand.txt
new file mode 100644 (file)
index 0000000..56d5c19
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/oxnas-nand.txt
@@ -0,0 +1,41 @@
+* Oxford Semiconductor OXNAS NAND Controller
+
+Please refer to nand.txt for generic information regarding MTD NAND bindings.
+
+Required properties:
+ - compatible: "oxsemi,ox820-nand"
+ - reg: Base address and length for NAND mapped memory.
+
+Optional Properties:
+ - clocks: phandle to the NAND gate clock if needed.
+ - resets: phandle to the NAND reset control if needed.
+
+Example:
+
+nandc: nand-controller@41000000 {
+       compatible = "oxsemi,ox820-nand";
+       reg = <0x41000000 0x100000>;
+       clocks = <&stdclk CLK_820_NAND>;
+       resets = <&reset RESET_NAND>;
+       #address-cells = <1>;
+       #size-cells = <0>;
+
+       nand@0 {
+               reg = <0>;
+               #address-cells = <1>;
+               #size-cells = <1>;
+               nand-ecc-mode = "soft";
+               nand-ecc-algo = "hamming";
+
+               partition@0 {
+                       label = "boot";
+                       reg = <0x00000000 0x00e00000>;
+                       read-only;
+               };
+
+               partition@e00000 {
+                       label = "ubi";
+                       reg = <0x00e00000 0x07200000>;
+               };
+       };
+};

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 7b7a887b4709f0122f32b60833d8c2e36bc4dead..c023125989cfdb0967831119cb9c769f7b784305 100644 (file)
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -426,6 +426,11 @@ config MTD_NAND_ORION
          No board specific support is done by this driver, each board
          must advertise a platform_device for the driver to attach.
 
+config MTD_NAND_OXNAS
+       tristate "NAND Flash support for Oxford Semiconductor SoC"
+       help
+         This enables the NAND flash controller on Oxford Semiconductor SoCs.
+
 config MTD_NAND_FSL_ELBC
        tristate "NAND support for Freescale eLBC controllers"
        depends on FSL_SOC

diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index cafde6f3d95761263d4c5af1395b11bfc000ca9b..05fc054a94721ae6a54674d60ce21e5ee8d0f19f 100644 (file)
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_MTD_NAND_TMIO)           += tmio_nand.o
 obj-$(CONFIG_MTD_NAND_PLATFORM)                += plat_nand.o
 obj-$(CONFIG_MTD_NAND_PASEMI)          += pasemi_nand.o
 obj-$(CONFIG_MTD_NAND_ORION)           += orion_nand.o
+obj-$(CONFIG_MTD_NAND_OXNAS)           += oxnas_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_ELBC)                += fsl_elbc_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_IFC)         += fsl_ifc_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_UPM)         += fsl_upm.o

diff --git a/drivers/mtd/nand/oxnas_nand.c b/drivers/mtd/nand/oxnas_nand.c
new file mode 100644 (file)
index 0000000..3e3bf3b
--- /dev/null
+++ b/drivers/mtd/nand/oxnas_nand.c
@@ -0,0 +1,195 @@
+/*
+ * Oxford Semiconductor OXNAS NAND driver
+
+ * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
+ * Heavily based on plat_nand.c :
+ * Author: Vitaly Wool <vitalywool@gmail.com>
+ * Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
+ * Copyright (C) 2012 John Crispin <blogic@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/reset.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of.h>
+
+/* Nand commands */
+#define OXNAS_NAND_CMD_ALE             BIT(18)
+#define OXNAS_NAND_CMD_CLE             BIT(19)
+
+#define OXNAS_NAND_MAX_CHIPS   1
+
+struct oxnas_nand_ctrl {
+       struct nand_hw_control base;
+       void __iomem *io_base;
+       struct clk *clk;
+       struct nand_chip *chips[OXNAS_NAND_MAX_CHIPS];
+};
+
+static uint8_t oxnas_nand_read_byte(struct mtd_info *mtd)
+{
+       struct nand_chip *chip = mtd_to_nand(mtd);
+       struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
+
+       return readb(oxnas->io_base);
+}
+
+static void oxnas_nand_read_buf(struct mtd_info *mtd, u8 *buf, int len)
+{
+       struct nand_chip *chip = mtd_to_nand(mtd);
+       struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
+
+       ioread8_rep(oxnas->io_base, buf, len);
+}
+
+static void oxnas_nand_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
+{
+       struct nand_chip *chip = mtd_to_nand(mtd);
+       struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
+
+       iowrite8_rep(oxnas->io_base, buf, len);
+}
+
+/* Single CS command control */
+static void oxnas_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
+                               unsigned int ctrl)
+{
+       struct nand_chip *chip = mtd_to_nand(mtd);
+       struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
+
+       if (ctrl & NAND_CLE)
+               writeb(cmd, oxnas->io_base + OXNAS_NAND_CMD_CLE);
+       else if (ctrl & NAND_ALE)
+               writeb(cmd, oxnas->io_base + OXNAS_NAND_CMD_ALE);
+}
+
+/*
+ * Probe for the NAND device.
+ */
+static int oxnas_nand_probe(struct platform_device *pdev)
+{
+       struct device_node *np = pdev->dev.of_node;
+       struct device_node *nand_np;
+       struct oxnas_nand_ctrl *oxnas;
+       struct nand_chip *chip;
+       struct mtd_info *mtd;
+       struct resource *res;
+       int nchips = 0;
+       int count = 0;
+       int err = 0;
+
+       /* Allocate memory for the device structure (and zero it) */
+       oxnas = devm_kzalloc(&pdev->dev, sizeof(struct nand_chip),
+                            GFP_KERNEL);
+       if (!oxnas)
+               return -ENOMEM;
+
+       nand_hw_control_init(&oxnas->base);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       oxnas->io_base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(oxnas->io_base))
+               return PTR_ERR(oxnas->io_base);
+
+       oxnas->clk = devm_clk_get(&pdev->dev, NULL);
+       if (IS_ERR(oxnas->clk))
+               oxnas->clk = NULL;
+
+       /* Only a single chip node is supported */
+       count = of_get_child_count(np);
+       if (count > 1)
+               return -EINVAL;
+
+       clk_prepare_enable(oxnas->clk);
+       device_reset_optional(&pdev->dev);
+
+       for_each_child_of_node(np, nand_np) {
+               chip = devm_kzalloc(&pdev->dev, sizeof(struct nand_chip),
+                                   GFP_KERNEL);
+               if (!chip)
+                       return -ENOMEM;
+
+               chip->controller = &oxnas->base;
+
+               nand_set_flash_node(chip, nand_np);
+               nand_set_controller_data(chip, oxnas);
+
+               mtd = nand_to_mtd(chip);
+               mtd->dev.parent = &pdev->dev;
+               mtd->priv = chip;
+
+               chip->cmd_ctrl = oxnas_nand_cmd_ctrl;
+               chip->read_buf = oxnas_nand_read_buf;
+               chip->read_byte = oxnas_nand_read_byte;
+               chip->write_buf = oxnas_nand_write_buf;
+               chip->chip_delay = 30;
+
+               /* Scan to find existence of the device */
+               err = nand_scan(mtd, 1);
+               if (err)
+                       return err;
+
+               err = mtd_device_register(mtd, NULL, 0);
+               if (err) {
+                       nand_release(mtd);
+                       return err;
+               }
+
+               oxnas->chips[nchips] = chip;
+               ++nchips;
+       }
+
+       /* Exit if no chips found */
+       if (!nchips)
+               return -ENODEV;
+
+       platform_set_drvdata(pdev, oxnas);
+
+       return 0;
+}
+
+static int oxnas_nand_remove(struct platform_device *pdev)
+{
+       struct oxnas_nand_ctrl *oxnas = platform_get_drvdata(pdev);
+
+       if (oxnas->chips[0])
+               nand_release(nand_to_mtd(oxnas->chips[0]));
+
+       clk_disable_unprepare(oxnas->clk);
+
+       return 0;
+}
+
+static const struct of_device_id oxnas_nand_match[] = {
+       { .compatible = "oxsemi,ox820-nand" },
+       {},
+};
+MODULE_DEVICE_TABLE(of, oxnas_nand_match);
+
+static struct platform_driver oxnas_nand_driver = {
+       .probe  = oxnas_nand_probe,
+       .remove = oxnas_nand_remove,
+       .driver = {
+               .name           = "oxnas_nand",
+               .of_match_table = oxnas_nand_match,
+       },
+};
+
+module_platform_driver(oxnas_nand_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_DESCRIPTION("Oxnas NAND driver");
+MODULE_ALIAS("platform:oxnas_nand");