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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/mtd/nand/raw/gpio.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/mtd/nand/raw/gpio.c')
-rw-r--r-- | drivers/mtd/nand/raw/gpio.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/drivers/mtd/nand/raw/gpio.c b/drivers/mtd/nand/raw/gpio.c new file mode 100644 index 0000000000..d6cc2cb652 --- /dev/null +++ b/drivers/mtd/nand/raw/gpio.c @@ -0,0 +1,406 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Updated, and converted to generic GPIO based driver by Russell King. + * + * Written by Ben Dooks <ben@simtec.co.uk> + * Based on 2.4 version by Mark Whittaker + * + * © 2004 Simtec Electronics + * + * Device driver for NAND flash that uses a memory mapped interface to + * read/write the NAND commands and data, and GPIO pins for control signals + * (the DT binding refers to this as "GPIO assisted NAND flash") + */ + +#include <linux/kernel.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/gpio/consumer.h> +#include <linux/io.h> +#include <linux/mtd/mtd.h> +#include <linux/mtd/rawnand.h> +#include <linux/mtd/partitions.h> +#include <linux/mtd/nand-gpio.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/delay.h> + +struct gpiomtd { + struct nand_controller base; + void __iomem *io; + void __iomem *io_sync; + struct nand_chip nand_chip; + struct gpio_nand_platdata plat; + struct gpio_desc *nce; /* Optional chip enable */ + struct gpio_desc *cle; + struct gpio_desc *ale; + struct gpio_desc *rdy; + struct gpio_desc *nwp; /* Optional write protection */ +}; + +static inline struct gpiomtd *gpio_nand_getpriv(struct mtd_info *mtd) +{ + return container_of(mtd_to_nand(mtd), struct gpiomtd, nand_chip); +} + + +#ifdef CONFIG_ARM +/* gpio_nand_dosync() + * + * Make sure the GPIO state changes occur in-order with writes to NAND + * memory region. + * Needed on PXA due to bus-reordering within the SoC itself (see section on + * I/O ordering in PXA manual (section 2.3, p35) + */ +static void gpio_nand_dosync(struct gpiomtd *gpiomtd) +{ + unsigned long tmp; + + if (gpiomtd->io_sync) { + /* + * Linux memory barriers don't cater for what's required here. + * What's required is what's here - a read from a separate + * region with a dependency on that read. + */ + tmp = readl(gpiomtd->io_sync); + asm volatile("mov %1, %0\n" : "=r" (tmp) : "r" (tmp)); + } +} +#else +static inline void gpio_nand_dosync(struct gpiomtd *gpiomtd) {} +#endif + +static int gpio_nand_exec_instr(struct nand_chip *chip, + const struct nand_op_instr *instr) +{ + struct gpiomtd *gpiomtd = gpio_nand_getpriv(nand_to_mtd(chip)); + unsigned int i; + + switch (instr->type) { + case NAND_OP_CMD_INSTR: + gpio_nand_dosync(gpiomtd); + gpiod_set_value(gpiomtd->cle, 1); + gpio_nand_dosync(gpiomtd); + writeb(instr->ctx.cmd.opcode, gpiomtd->io); + gpio_nand_dosync(gpiomtd); + gpiod_set_value(gpiomtd->cle, 0); + return 0; + + case NAND_OP_ADDR_INSTR: + gpio_nand_dosync(gpiomtd); + gpiod_set_value(gpiomtd->ale, 1); + gpio_nand_dosync(gpiomtd); + for (i = 0; i < instr->ctx.addr.naddrs; i++) + writeb(instr->ctx.addr.addrs[i], gpiomtd->io); + gpio_nand_dosync(gpiomtd); + gpiod_set_value(gpiomtd->ale, 0); + return 0; + + case NAND_OP_DATA_IN_INSTR: + gpio_nand_dosync(gpiomtd); + if ((chip->options & NAND_BUSWIDTH_16) && + !instr->ctx.data.force_8bit) + ioread16_rep(gpiomtd->io, instr->ctx.data.buf.in, + instr->ctx.data.len / 2); + else + ioread8_rep(gpiomtd->io, instr->ctx.data.buf.in, + instr->ctx.data.len); + return 0; + + case NAND_OP_DATA_OUT_INSTR: + gpio_nand_dosync(gpiomtd); + if ((chip->options & NAND_BUSWIDTH_16) && + !instr->ctx.data.force_8bit) + iowrite16_rep(gpiomtd->io, instr->ctx.data.buf.out, + instr->ctx.data.len / 2); + else + iowrite8_rep(gpiomtd->io, instr->ctx.data.buf.out, + instr->ctx.data.len); + return 0; + + case NAND_OP_WAITRDY_INSTR: + if (!gpiomtd->rdy) + return nand_soft_waitrdy(chip, instr->ctx.waitrdy.timeout_ms); + + return nand_gpio_waitrdy(chip, gpiomtd->rdy, + instr->ctx.waitrdy.timeout_ms); + + default: + return -EINVAL; + } + + return 0; +} + +static int gpio_nand_exec_op(struct nand_chip *chip, + const struct nand_operation *op, + bool check_only) +{ + struct gpiomtd *gpiomtd = gpio_nand_getpriv(nand_to_mtd(chip)); + unsigned int i; + int ret = 0; + + if (check_only) + return 0; + + gpio_nand_dosync(gpiomtd); + gpiod_set_value(gpiomtd->nce, 0); + for (i = 0; i < op->ninstrs; i++) { + ret = gpio_nand_exec_instr(chip, &op->instrs[i]); + if (ret) + break; + + if (op->instrs[i].delay_ns) + ndelay(op->instrs[i].delay_ns); + } + gpio_nand_dosync(gpiomtd); + gpiod_set_value(gpiomtd->nce, 1); + + return ret; +} + +static int gpio_nand_attach_chip(struct nand_chip *chip) +{ + if (chip->ecc.engine_type == NAND_ECC_ENGINE_TYPE_SOFT && + chip->ecc.algo == NAND_ECC_ALGO_UNKNOWN) + chip->ecc.algo = NAND_ECC_ALGO_HAMMING; + + return 0; +} + +static const struct nand_controller_ops gpio_nand_ops = { + .exec_op = gpio_nand_exec_op, + .attach_chip = gpio_nand_attach_chip, +}; + +#ifdef CONFIG_OF +static const struct of_device_id gpio_nand_id_table[] = { + { .compatible = "gpio-control-nand" }, + {} +}; +MODULE_DEVICE_TABLE(of, gpio_nand_id_table); + +static int gpio_nand_get_config_of(const struct device *dev, + struct gpio_nand_platdata *plat) +{ + u32 val; + + if (!dev->of_node) + return -ENODEV; + + if (!of_property_read_u32(dev->of_node, "bank-width", &val)) { + if (val == 2) { + plat->options |= NAND_BUSWIDTH_16; + } else if (val != 1) { + dev_err(dev, "invalid bank-width %u\n", val); + return -EINVAL; + } + } + + if (!of_property_read_u32(dev->of_node, "chip-delay", &val)) + plat->chip_delay = val; + + return 0; +} + +static struct resource *gpio_nand_get_io_sync_of(struct platform_device *pdev) +{ + struct resource *r; + u64 addr; + + if (of_property_read_u64(pdev->dev.of_node, + "gpio-control-nand,io-sync-reg", &addr)) + return NULL; + + r = devm_kzalloc(&pdev->dev, sizeof(*r), GFP_KERNEL); + if (!r) + return NULL; + + r->start = addr; + r->end = r->start + 0x3; + r->flags = IORESOURCE_MEM; + + return r; +} +#else /* CONFIG_OF */ +static inline int gpio_nand_get_config_of(const struct device *dev, + struct gpio_nand_platdata *plat) +{ + return -ENOSYS; +} + +static inline struct resource * +gpio_nand_get_io_sync_of(struct platform_device *pdev) +{ + return NULL; +} +#endif /* CONFIG_OF */ + +static inline int gpio_nand_get_config(const struct device *dev, + struct gpio_nand_platdata *plat) +{ + int ret = gpio_nand_get_config_of(dev, plat); + + if (!ret) + return ret; + + if (dev_get_platdata(dev)) { + memcpy(plat, dev_get_platdata(dev), sizeof(*plat)); + return 0; + } + + return -EINVAL; +} + +static inline struct resource * +gpio_nand_get_io_sync(struct platform_device *pdev) +{ + struct resource *r = gpio_nand_get_io_sync_of(pdev); + + if (r) + return r; + + return platform_get_resource(pdev, IORESOURCE_MEM, 1); +} + +static void gpio_nand_remove(struct platform_device *pdev) +{ + struct gpiomtd *gpiomtd = platform_get_drvdata(pdev); + struct nand_chip *chip = &gpiomtd->nand_chip; + int ret; + + ret = mtd_device_unregister(nand_to_mtd(chip)); + WARN_ON(ret); + nand_cleanup(chip); + + /* Enable write protection and disable the chip */ + if (gpiomtd->nwp && !IS_ERR(gpiomtd->nwp)) + gpiod_set_value(gpiomtd->nwp, 0); + if (gpiomtd->nce && !IS_ERR(gpiomtd->nce)) + gpiod_set_value(gpiomtd->nce, 0); +} + +static int gpio_nand_probe(struct platform_device *pdev) +{ + struct gpiomtd *gpiomtd; + struct nand_chip *chip; + struct mtd_info *mtd; + struct resource *res; + struct device *dev = &pdev->dev; + int ret = 0; + + if (!dev->of_node && !dev_get_platdata(dev)) + return -EINVAL; + + gpiomtd = devm_kzalloc(dev, sizeof(*gpiomtd), GFP_KERNEL); + if (!gpiomtd) + return -ENOMEM; + + chip = &gpiomtd->nand_chip; + + gpiomtd->io = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(gpiomtd->io)) + return PTR_ERR(gpiomtd->io); + + res = gpio_nand_get_io_sync(pdev); + if (res) { + gpiomtd->io_sync = devm_ioremap_resource(dev, res); + if (IS_ERR(gpiomtd->io_sync)) + return PTR_ERR(gpiomtd->io_sync); + } + + ret = gpio_nand_get_config(dev, &gpiomtd->plat); + if (ret) + return ret; + + /* Just enable the chip */ + gpiomtd->nce = devm_gpiod_get_optional(dev, "nce", GPIOD_OUT_HIGH); + if (IS_ERR(gpiomtd->nce)) + return PTR_ERR(gpiomtd->nce); + + /* We disable write protection once we know probe() will succeed */ + gpiomtd->nwp = devm_gpiod_get_optional(dev, "nwp", GPIOD_OUT_LOW); + if (IS_ERR(gpiomtd->nwp)) { + ret = PTR_ERR(gpiomtd->nwp); + goto out_ce; + } + + gpiomtd->ale = devm_gpiod_get(dev, "ale", GPIOD_OUT_LOW); + if (IS_ERR(gpiomtd->ale)) { + ret = PTR_ERR(gpiomtd->ale); + goto out_ce; + } + + gpiomtd->cle = devm_gpiod_get(dev, "cle", GPIOD_OUT_LOW); + if (IS_ERR(gpiomtd->cle)) { + ret = PTR_ERR(gpiomtd->cle); + goto out_ce; + } + + gpiomtd->rdy = devm_gpiod_get_optional(dev, "rdy", GPIOD_IN); + if (IS_ERR(gpiomtd->rdy)) { + ret = PTR_ERR(gpiomtd->rdy); + goto out_ce; + } + + nand_controller_init(&gpiomtd->base); + gpiomtd->base.ops = &gpio_nand_ops; + + nand_set_flash_node(chip, pdev->dev.of_node); + chip->options = gpiomtd->plat.options; + chip->controller = &gpiomtd->base; + + mtd = nand_to_mtd(chip); + mtd->dev.parent = dev; + + platform_set_drvdata(pdev, gpiomtd); + + /* Disable write protection, if wired up */ + if (gpiomtd->nwp && !IS_ERR(gpiomtd->nwp)) + gpiod_direction_output(gpiomtd->nwp, 1); + + /* + * This driver assumes that the default ECC engine should be TYPE_SOFT. + * Set ->engine_type before registering the NAND devices in order to + * provide a driver specific default value. + */ + chip->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT; + + ret = nand_scan(chip, 1); + if (ret) + goto err_wp; + + if (gpiomtd->plat.adjust_parts) + gpiomtd->plat.adjust_parts(&gpiomtd->plat, mtd->size); + + ret = mtd_device_register(mtd, gpiomtd->plat.parts, + gpiomtd->plat.num_parts); + if (!ret) + return 0; + +err_wp: + if (gpiomtd->nwp && !IS_ERR(gpiomtd->nwp)) + gpiod_set_value(gpiomtd->nwp, 0); +out_ce: + if (gpiomtd->nce && !IS_ERR(gpiomtd->nce)) + gpiod_set_value(gpiomtd->nce, 0); + + return ret; +} + +static struct platform_driver gpio_nand_driver = { + .probe = gpio_nand_probe, + .remove_new = gpio_nand_remove, + .driver = { + .name = "gpio-nand", + .of_match_table = of_match_ptr(gpio_nand_id_table), + }, +}; + +module_platform_driver(gpio_nand_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); +MODULE_DESCRIPTION("GPIO NAND Driver"); |