1 files changed, 447 insertions, 0 deletions

diff --git a/drivers/mtd/nand/raw/ams-delta.c b/drivers/mtd/nand/raw/ams-delta.c
new file mode 100644
index 000000000..919816a7a
--- /dev/null
+++ b/drivers/mtd/nand/raw/ams-delta.c
@@ -0,0 +1,447 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Copyright (C) 2006 Jonathan McDowell <noodles@earth.li>
+ *
+ *  Derived from drivers/mtd/nand/toto.c (removed in v2.6.28)
+ *    Copyright (c) 2003 Texas Instruments
+ *    Copyright (c) 2002 Thomas Gleixner <tgxl@linutronix.de>
+ *
+ *  Converted to platform driver by Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
+ *  Partially stolen from plat_nand.c
+ *
+ *  Overview:
+ *   This is a device driver for the NAND flash device found on the
+ *   Amstrad E3 (Delta).
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand-gpio.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/sizes.h>
+
+/*
+ * MTD structure for E3 (Delta)
+ */
+struct gpio_nand {
+	struct nand_controller	base;
+	struct nand_chip	nand_chip;
+	struct gpio_desc	*gpiod_rdy;
+	struct gpio_desc	*gpiod_nce;
+	struct gpio_desc	*gpiod_nre;
+	struct gpio_desc	*gpiod_nwp;
+	struct gpio_desc	*gpiod_nwe;
+	struct gpio_desc	*gpiod_ale;
+	struct gpio_desc	*gpiod_cle;
+	struct gpio_descs	*data_gpiods;
+	bool			data_in;
+	unsigned int		tRP;
+	unsigned int		tWP;
+	u8			(*io_read)(struct gpio_nand *this);
+	void			(*io_write)(struct gpio_nand *this, u8 byte);
+};
+
+static void gpio_nand_write_commit(struct gpio_nand *priv)
+{
+	gpiod_set_value(priv->gpiod_nwe, 1);
+	ndelay(priv->tWP);
+	gpiod_set_value(priv->gpiod_nwe, 0);
+}
+
+static void gpio_nand_io_write(struct gpio_nand *priv, u8 byte)
+{
+	struct gpio_descs *data_gpiods = priv->data_gpiods;
+	DECLARE_BITMAP(values, BITS_PER_TYPE(byte)) = { byte, };
+
+	gpiod_set_raw_array_value(data_gpiods->ndescs, data_gpiods->desc,
+				  data_gpiods->info, values);
+
+	gpio_nand_write_commit(priv);
+}
+
+static void gpio_nand_dir_output(struct gpio_nand *priv, u8 byte)
+{
+	struct gpio_descs *data_gpiods = priv->data_gpiods;
+	DECLARE_BITMAP(values, BITS_PER_TYPE(byte)) = { byte, };
+	int i;
+
+	for (i = 0; i < data_gpiods->ndescs; i++)
+		gpiod_direction_output_raw(data_gpiods->desc[i],
+					   test_bit(i, values));
+
+	gpio_nand_write_commit(priv);
+
+	priv->data_in = false;
+}
+
+static u8 gpio_nand_io_read(struct gpio_nand *priv)
+{
+	u8 res;
+	struct gpio_descs *data_gpiods = priv->data_gpiods;
+	DECLARE_BITMAP(values, BITS_PER_TYPE(res)) = { 0, };
+
+	gpiod_set_value(priv->gpiod_nre, 1);
+	ndelay(priv->tRP);
+
+	gpiod_get_raw_array_value(data_gpiods->ndescs, data_gpiods->desc,
+				  data_gpiods->info, values);
+
+	gpiod_set_value(priv->gpiod_nre, 0);
+
+	res = values[0];
+	return res;
+}
+
+static void gpio_nand_dir_input(struct gpio_nand *priv)
+{
+	struct gpio_descs *data_gpiods = priv->data_gpiods;
+	int i;
+
+	for (i = 0; i < data_gpiods->ndescs; i++)
+		gpiod_direction_input(data_gpiods->desc[i]);
+
+	priv->data_in = true;
+}
+
+static void gpio_nand_write_buf(struct gpio_nand *priv, const u8 *buf, int len)
+{
+	int i = 0;
+
+	if (len > 0 && priv->data_in)
+		gpio_nand_dir_output(priv, buf[i++]);
+
+	while (i < len)
+		priv->io_write(priv, buf[i++]);
+}
+
+static void gpio_nand_read_buf(struct gpio_nand *priv, u8 *buf, int len)
+{
+	int i;
+
+	if (priv->data_gpiods && !priv->data_in)
+		gpio_nand_dir_input(priv);
+
+	for (i = 0; i < len; i++)
+		buf[i] = priv->io_read(priv);
+}
+
+static void gpio_nand_ctrl_cs(struct gpio_nand *priv, bool assert)
+{
+	gpiod_set_value(priv->gpiod_nce, assert);
+}
+
+static int gpio_nand_exec_op(struct nand_chip *this,
+			     const struct nand_operation *op, bool check_only)
+{
+	struct gpio_nand *priv = nand_get_controller_data(this);
+	const struct nand_op_instr *instr;
+	int ret = 0;
+
+	if (check_only)
+		return 0;
+
+	gpio_nand_ctrl_cs(priv, 1);
+
+	for (instr = op->instrs; instr < op->instrs + op->ninstrs; instr++) {
+		switch (instr->type) {
+		case NAND_OP_CMD_INSTR:
+			gpiod_set_value(priv->gpiod_cle, 1);
+			gpio_nand_write_buf(priv, &instr->ctx.cmd.opcode, 1);
+			gpiod_set_value(priv->gpiod_cle, 0);
+			break;
+
+		case NAND_OP_ADDR_INSTR:
+			gpiod_set_value(priv->gpiod_ale, 1);
+			gpio_nand_write_buf(priv, instr->ctx.addr.addrs,
+					    instr->ctx.addr.naddrs);
+			gpiod_set_value(priv->gpiod_ale, 0);
+			break;
+
+		case NAND_OP_DATA_IN_INSTR:
+			gpio_nand_read_buf(priv, instr->ctx.data.buf.in,
+					   instr->ctx.data.len);
+			break;
+
+		case NAND_OP_DATA_OUT_INSTR:
+			gpio_nand_write_buf(priv, instr->ctx.data.buf.out,
+					    instr->ctx.data.len);
+			break;
+
+		case NAND_OP_WAITRDY_INSTR:
+			ret = priv->gpiod_rdy ?
+			      nand_gpio_waitrdy(this, priv->gpiod_rdy,
+						instr->ctx.waitrdy.timeout_ms) :
+			      nand_soft_waitrdy(this,
+						instr->ctx.waitrdy.timeout_ms);
+			break;
+		}
+
+		if (ret)
+			break;
+	}
+
+	gpio_nand_ctrl_cs(priv, 0);
+
+	return ret;
+}
+
+static int gpio_nand_setup_interface(struct nand_chip *this, int csline,
+				     const struct nand_interface_config *cf)
+{
+	struct gpio_nand *priv = nand_get_controller_data(this);
+	const struct nand_sdr_timings *sdr = nand_get_sdr_timings(cf);
+	struct device *dev = &nand_to_mtd(this)->dev;
+
+	if (IS_ERR(sdr))
+		return PTR_ERR(sdr);
+
+	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+		return 0;
+
+	if (priv->gpiod_nre) {
+		priv->tRP = DIV_ROUND_UP(sdr->tRP_min, 1000);
+		dev_dbg(dev, "using %u ns read pulse width\n", priv->tRP);
+	}
+
+	priv->tWP = DIV_ROUND_UP(sdr->tWP_min, 1000);
+	dev_dbg(dev, "using %u ns write pulse width\n", priv->tWP);
+
+	return 0;
+}
+
+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,
+	.setup_interface = gpio_nand_setup_interface,
+};
+
+/*
+ * Main initialization routine
+ */
+static int gpio_nand_probe(struct platform_device *pdev)
+{
+	struct gpio_nand_platdata *pdata = dev_get_platdata(&pdev->dev);
+	const struct mtd_partition *partitions = NULL;
+	int num_partitions = 0;
+	struct gpio_nand *priv;
+	struct nand_chip *this;
+	struct mtd_info *mtd;
+	int (*probe)(struct platform_device *pdev, struct gpio_nand *priv);
+	int err = 0;
+
+	if (pdata) {
+		partitions = pdata->parts;
+		num_partitions = pdata->num_parts;
+	}
+
+	/* Allocate memory for MTD device structure and private data */
+	priv = devm_kzalloc(&pdev->dev, sizeof(struct gpio_nand),
+			    GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	this = &priv->nand_chip;
+
+	mtd = nand_to_mtd(this);
+	mtd->dev.parent = &pdev->dev;
+
+	nand_set_controller_data(this, priv);
+	nand_set_flash_node(this, pdev->dev.of_node);
+
+	priv->gpiod_rdy = devm_gpiod_get_optional(&pdev->dev, "rdy", GPIOD_IN);
+	if (IS_ERR(priv->gpiod_rdy)) {
+		err = PTR_ERR(priv->gpiod_rdy);
+		dev_warn(&pdev->dev, "RDY GPIO request failed (%d)\n", err);
+		return err;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	/* Set chip enabled but write protected */
+	priv->gpiod_nwp = devm_gpiod_get_optional(&pdev->dev, "nwp",
+						  GPIOD_OUT_HIGH);
+	if (IS_ERR(priv->gpiod_nwp)) {
+		err = PTR_ERR(priv->gpiod_nwp);
+		dev_err(&pdev->dev, "NWP GPIO request failed (%d)\n", err);
+		return err;
+	}
+
+	priv->gpiod_nce = devm_gpiod_get_optional(&pdev->dev, "nce",
+						  GPIOD_OUT_LOW);
+	if (IS_ERR(priv->gpiod_nce)) {
+		err = PTR_ERR(priv->gpiod_nce);
+		dev_err(&pdev->dev, "NCE GPIO request failed (%d)\n", err);
+		return err;
+	}
+
+	priv->gpiod_nre = devm_gpiod_get_optional(&pdev->dev, "nre",
+						  GPIOD_OUT_LOW);
+	if (IS_ERR(priv->gpiod_nre)) {
+		err = PTR_ERR(priv->gpiod_nre);
+		dev_err(&pdev->dev, "NRE GPIO request failed (%d)\n", err);
+		return err;
+	}
+
+	priv->gpiod_nwe = devm_gpiod_get_optional(&pdev->dev, "nwe",
+						  GPIOD_OUT_LOW);
+	if (IS_ERR(priv->gpiod_nwe)) {
+		err = PTR_ERR(priv->gpiod_nwe);
+		dev_err(&pdev->dev, "NWE GPIO request failed (%d)\n", err);
+		return err;
+	}
+
+	priv->gpiod_ale = devm_gpiod_get(&pdev->dev, "ale", GPIOD_OUT_LOW);
+	if (IS_ERR(priv->gpiod_ale)) {
+		err = PTR_ERR(priv->gpiod_ale);
+		dev_err(&pdev->dev, "ALE GPIO request failed (%d)\n", err);
+		return err;
+	}
+
+	priv->gpiod_cle = devm_gpiod_get(&pdev->dev, "cle", GPIOD_OUT_LOW);
+	if (IS_ERR(priv->gpiod_cle)) {
+		err = PTR_ERR(priv->gpiod_cle);
+		dev_err(&pdev->dev, "CLE GPIO request failed (%d)\n", err);
+		return err;
+	}
+
+	/* Request array of data pins, initialize them as input */
+	priv->data_gpiods = devm_gpiod_get_array_optional(&pdev->dev, "data",
+							  GPIOD_IN);
+	if (IS_ERR(priv->data_gpiods)) {
+		err = PTR_ERR(priv->data_gpiods);
+		dev_err(&pdev->dev, "data GPIO request failed: %d\n", err);
+		return err;
+	}
+	if (priv->data_gpiods) {
+		if (!priv->gpiod_nwe) {
+			dev_err(&pdev->dev,
+				"mandatory NWE pin not provided by platform\n");
+			return -ENODEV;
+		}
+
+		priv->io_read = gpio_nand_io_read;
+		priv->io_write = gpio_nand_io_write;
+		priv->data_in = true;
+	}
+
+	if (pdev->id_entry)
+		probe = (void *) pdev->id_entry->driver_data;
+	else
+		probe = of_device_get_match_data(&pdev->dev);
+	if (probe)
+		err = probe(pdev, priv);
+	if (err)
+		return err;
+
+	if (!priv->io_read || !priv->io_write) {
+		dev_err(&pdev->dev, "incomplete device configuration\n");
+		return -ENODEV;
+	}
+
+	/* Initialize the NAND controller object embedded in gpio_nand. */
+	priv->base.ops = &gpio_nand_ops;
+	nand_controller_init(&priv->base);
+	this->controller = &priv->base;
+
+	/*
+	 * FIXME: We should release write protection only after nand_scan() to
+	 * be on the safe side but we can't do that until we have a generic way
+	 * to assert/deassert WP from the core.  Even if the core shouldn't
+	 * write things in the nand_scan() path, it should have control on this
+	 * pin just in case we ever need to disable write protection during
+	 * chip detection/initialization.
+	 */
+	/* Release write protection */
+	gpiod_set_value(priv->gpiod_nwp, 0);
+
+	/*
+	 * 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.
+	 */
+	this->ecc.engine_type = NAND_ECC_ENGINE_TYPE_SOFT;
+
+	/* Scan to find existence of the device */
+	err = nand_scan(this, 1);
+	if (err)
+		return err;
+
+	/* Register the partitions */
+	err = mtd_device_register(mtd, partitions, num_partitions);
+	if (err)
+		goto err_nand_cleanup;
+
+	return 0;
+
+err_nand_cleanup:
+	nand_cleanup(this);
+
+	return err;
+}
+
+/*
+ * Clean up routine
+ */
+static void gpio_nand_remove(struct platform_device *pdev)
+{
+	struct gpio_nand *priv = platform_get_drvdata(pdev);
+	struct mtd_info *mtd = nand_to_mtd(&priv->nand_chip);
+	int ret;
+
+	/* Apply write protection */
+	gpiod_set_value(priv->gpiod_nwp, 1);
+
+	/* Unregister device */
+	ret = mtd_device_unregister(mtd);
+	WARN_ON(ret);
+	nand_cleanup(mtd_to_nand(mtd));
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id gpio_nand_of_id_table[] = {
+	{
+		/* sentinel */
+	},
+};
+MODULE_DEVICE_TABLE(of, gpio_nand_of_id_table);
+#endif
+
+static const struct platform_device_id gpio_nand_plat_id_table[] = {
+	{
+		.name	= "ams-delta-nand",
+	}, {
+		/* sentinel */
+	},
+};
+MODULE_DEVICE_TABLE(platform, gpio_nand_plat_id_table);
+
+static struct platform_driver gpio_nand_driver = {
+	.probe		= gpio_nand_probe,
+	.remove_new	= gpio_nand_remove,
+	.id_table	= gpio_nand_plat_id_table,
+	.driver		= {
+		.name	= "ams-delta-nand",
+		.of_match_table = of_match_ptr(gpio_nand_of_id_table),
+	},
+};
+
+module_platform_driver(gpio_nand_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Jonathan McDowell <noodles@earth.li>");
+MODULE_DESCRIPTION("Glue layer for NAND flash on Amstrad E3 (Delta)");