/* * 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");