diff options
Diffstat (limited to 'drivers/mtd/nand/oxnas_nand.c')
| -rw-r--r-- | drivers/mtd/nand/oxnas_nand.c | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/drivers/mtd/nand/oxnas_nand.c b/drivers/mtd/nand/oxnas_nand.c new file mode 100644 index 000000000000..3e3bf3b364d2 --- /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"); |