mtd: spi-nor: Move m25p80 code in spi-nor.c

The m25p80 driver is actually a generic wrapper around the spi-mem
layer. Not only the driver name is misleading, but we'd expect such a
common logic to be directly available in the core. Another reason for
moving this code is that SPI NOR controller drivers should
progressively be replaced by SPI controller drivers implementing the
spi_mem_ops interface, and when the conversion is done, we should have
a single spi-nor driver directly interfacing with the spi-mem layer.

While moving the code we also fix a longstanding issue when
non-DMA-able buffers are passed by the MTD layer.
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

drivers/mtd/devices/Kconfig

@@ -79,24 +79,6 @@ config MTD_DATAFLASH_OTP
 	  other key product data.  The second half is programmed with a
 	  unique-to-each-chip bit pattern at the factory.
 
-config MTD_M25P80
-	tristate "Support most SPI Flash chips (AT26DF, M25P, W25X, ...)"
-	depends on SPI_MASTER && MTD_SPI_NOR
-	select SPI_MEM
-	help
-	  This enables access to most modern SPI flash chips, used for
-	  program and data storage.   Series supported include Atmel AT26DF,
-	  Spansion S25SL, SST 25VF, ST M25P, and Winbond W25X.  Other chips
-	  are supported as well.  See the driver source for the current list,
-	  or to add other chips.
-
-	  Note that the original DataFlash chips (AT45 series, not AT26DF),
-	  need an entirely different driver.
-
-	  Set up your spi devices with the right board-specific platform data,
-	  if you want to specify device partitioning or to use a device which
-	  doesn't support the JEDEC ID instruction.
-
 config MTD_MCHP23K256
 	tristate "Microchip 23K256 SRAM"
 	depends on SPI_MASTER

drivers/mtd/devices/Makefile

@@ -12,7 +12,6 @@ obj-$(CONFIG_MTD_MTDRAM)	+= mtdram.o
 obj-$(CONFIG_MTD_LART)		+= lart.o
 obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
 obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o
-obj-$(CONFIG_MTD_M25P80)	+= m25p80.o
 obj-$(CONFIG_MTD_MCHP23K256)	+= mchp23k256.o
 obj-$(CONFIG_MTD_SPEAR_SMI)	+= spear_smi.o
 obj-$(CONFIG_MTD_SST25L)	+= sst25l.o

drivers/mtd/devices/m25p80.c

-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * MTD SPI driver for ST M25Pxx (and similar) serial flash chips
- *
- * Author: Mike Lavender, mike@steroidmicros.com
- *
- * Copyright (c) 2005, Intec Automation Inc.
- *
- * Some parts are based on lart.c by Abraham Van Der Merwe
- *
- * Cleaned up and generalized based on mtd_dataflash.c
- */
-
-#include <linux/err.h>
-#include <linux/errno.h>
-#include <linux/module.h>
-#include <linux/device.h>
-
-#include <linux/mtd/mtd.h>
-#include <linux/mtd/partitions.h>
-
-#include <linux/spi/spi.h>
-#include <linux/spi/spi-mem.h>
-#include <linux/spi/flash.h>
-#include <linux/mtd/spi-nor.h>
-
-struct m25p {
-	struct spi_mem		*spimem;
-	struct spi_nor		spi_nor;
-};
-
-static int m25p80_read_reg(struct spi_nor *nor, u8 code, u8 *val, int len)
-{
-	struct m25p *flash = nor->priv;
-	struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(code, 1),
-					  SPI_MEM_OP_NO_ADDR,
-					  SPI_MEM_OP_NO_DUMMY,
-					  SPI_MEM_OP_DATA_IN(len, NULL, 1));
-	void *scratchbuf;
-	int ret;
-
-	scratchbuf = kmalloc(len, GFP_KERNEL);
-	if (!scratchbuf)
-		return -ENOMEM;
-
-	op.data.buf.in = scratchbuf;
-	ret = spi_mem_exec_op(flash->spimem, &op);
-	if (ret < 0)
-		dev_err(&flash->spimem->spi->dev, "error %d reading %x\n", ret,
-			code);
-	else
-		memcpy(val, scratchbuf, len);
-
-	kfree(scratchbuf);
-
-	return ret;
-}
-
-static int m25p80_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
-{
-	struct m25p *flash = nor->priv;
-	struct spi_mem_op op = SPI_MEM_OP(SPI_MEM_OP_CMD(opcode, 1),
-					  SPI_MEM_OP_NO_ADDR,
-					  SPI_MEM_OP_NO_DUMMY,
-					  SPI_MEM_OP_DATA_OUT(len, NULL, 1));
-	void *scratchbuf;
-	int ret;
-
-	scratchbuf = kmemdup(buf, len, GFP_KERNEL);
-	if (!scratchbuf)
-		return -ENOMEM;
-
-	op.data.buf.out = scratchbuf;
-	ret = spi_mem_exec_op(flash->spimem, &op);
-	kfree(scratchbuf);
-
-	return ret;
-}
-
-static ssize_t m25p80_write(struct spi_nor *nor, loff_t to, size_t len,
-			    const u_char *buf)
-{
-	struct m25p *flash = nor->priv;
-	struct spi_mem_op op =
-			SPI_MEM_OP(SPI_MEM_OP_CMD(nor->program_opcode, 1),
-				   SPI_MEM_OP_ADDR(nor->addr_width, to, 1),
-				   SPI_MEM_OP_NO_DUMMY,
-				   SPI_MEM_OP_DATA_OUT(len, buf, 1));
-	int ret;
-
-	/* get transfer protocols. */
-	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->write_proto);
-	op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->write_proto);
-	op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->write_proto);
-
-	if (nor->program_opcode == SPINOR_OP_AAI_WP && nor->sst_write_second)
-		op.addr.nbytes = 0;
-
-	ret = spi_mem_adjust_op_size(flash->spimem, &op);
-	if (ret)
-		return ret;
-	op.data.nbytes = len < op.data.nbytes ? len : op.data.nbytes;
-
-	ret = spi_mem_exec_op(flash->spimem, &op);
-	if (ret)
-		return ret;
-
-	return op.data.nbytes;
-}
-
-/*
- * Read an address range from the nor chip.  The address range
- * may be any size provided it is within the physical boundaries.
- */
-static ssize_t m25p80_read(struct spi_nor *nor, loff_t from, size_t len,
-			   u_char *buf)
-{
-	struct m25p *flash = nor->priv;
-	struct spi_mem_op op =
-			SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 1),
-				   SPI_MEM_OP_ADDR(nor->addr_width, from, 1),
-				   SPI_MEM_OP_DUMMY(nor->read_dummy, 1),
-				   SPI_MEM_OP_DATA_IN(len, buf, 1));
-	size_t remaining = len;
-	int ret;
-
-	/* get transfer protocols. */
-	op.cmd.buswidth = spi_nor_get_protocol_inst_nbits(nor->read_proto);
-	op.addr.buswidth = spi_nor_get_protocol_addr_nbits(nor->read_proto);
-	op.dummy.buswidth = op.addr.buswidth;
-	op.data.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);
-
-	/* convert the dummy cycles to the number of bytes */
-	op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
-
-	while (remaining) {
-		op.data.nbytes = remaining < UINT_MAX ? remaining : UINT_MAX;
-		ret = spi_mem_adjust_op_size(flash->spimem, &op);
-		if (ret)
-			return ret;
-
-		ret = spi_mem_exec_op(flash->spimem, &op);
-		if (ret)
-			return ret;
-
-		op.addr.val += op.data.nbytes;
-		remaining -= op.data.nbytes;
-		op.data.buf.in += op.data.nbytes;
-	}
-
-	return len;
-}
-
-/*
- * board specific setup should have ensured the SPI clock used here
- * matches what the READ command supports, at least until this driver
- * understands FAST_READ (for clocks over 25 MHz).
- */
-static int m25p_probe(struct spi_mem *spimem)
-{
-	struct spi_device *spi = spimem->spi;
-	struct flash_platform_data	*data;
-	struct m25p *flash;
-	struct spi_nor *nor;
-	struct spi_nor_hwcaps hwcaps = {
-		.mask = SNOR_HWCAPS_READ |
-			SNOR_HWCAPS_READ_FAST |
-			SNOR_HWCAPS_PP,
-	};
-	char *flash_name;
-	int ret;
-
-	data = dev_get_platdata(&spimem->spi->dev);
-
-	flash = devm_kzalloc(&spimem->spi->dev, sizeof(*flash), GFP_KERNEL);
-	if (!flash)
-		return -ENOMEM;
-
-	nor = &flash->spi_nor;
-
-	/* install the hooks */
-	nor->read = m25p80_read;
-	nor->write = m25p80_write;
-	nor->write_reg = m25p80_write_reg;
-	nor->read_reg = m25p80_read_reg;
-
-	nor->dev = &spimem->spi->dev;
-	spi_nor_set_flash_node(nor, spi->dev.of_node);
-	nor->priv = flash;
-
-	spi_mem_set_drvdata(spimem, flash);
-	flash->spimem = spimem;
-
-	if (spi->mode & SPI_RX_OCTAL) {
-		hwcaps.mask |= SNOR_HWCAPS_READ_1_1_8;
-
-		if (spi->mode & SPI_TX_OCTAL)
-			hwcaps.mask |= (SNOR_HWCAPS_READ_1_8_8 |
-					SNOR_HWCAPS_PP_1_1_8 |
-					SNOR_HWCAPS_PP_1_8_8);
-	} else if (spi->mode & SPI_RX_QUAD) {
-		hwcaps.mask |= SNOR_HWCAPS_READ_1_1_4;
-
-		if (spi->mode & SPI_TX_QUAD)
-			hwcaps.mask |= (SNOR_HWCAPS_READ_1_4_4 |
-					SNOR_HWCAPS_PP_1_1_4 |
-					SNOR_HWCAPS_PP_1_4_4);
-	} else if (spi->mode & SPI_RX_DUAL) {
-		hwcaps.mask |= SNOR_HWCAPS_READ_1_1_2;
-
-		if (spi->mode & SPI_TX_DUAL)
-			hwcaps.mask |= SNOR_HWCAPS_READ_1_2_2;
-	}
-
-	if (data && data->name)
-		nor->mtd.name = data->name;
-
-	if (!nor->mtd.name)
-		nor->mtd.name = spi_mem_get_name(spimem);
-
-	/* For some (historical?) reason many platforms provide two different
-	 * names in flash_platform_data: "name" and "type". Quite often name is
-	 * set to "m25p80" and then "type" provides a real chip name.
-	 * If that's the case, respect "type" and ignore a "name".
-	 */
-	if (data && data->type)
-		flash_name = data->type;
-	else if (!strcmp(spi->modalias, "spi-nor"))
-		flash_name = NULL; /* auto-detect */
-	else
-		flash_name = spi->modalias;
-
-	ret = spi_nor_scan(nor, flash_name, &hwcaps);
-	if (ret)
-		return ret;
-
-	return mtd_device_register(&nor->mtd, data ? data->parts : NULL,
-				   data ? data->nr_parts : 0);
-}
-
-
-static int m25p_remove(struct spi_mem *spimem)
-{
-	struct m25p	*flash = spi_mem_get_drvdata(spimem);
-
-	spi_nor_restore(&flash->spi_nor);
-
-	/* Clean up MTD stuff. */
-	return mtd_device_unregister(&flash->spi_nor.mtd);
-}
-
-static void m25p_shutdown(struct spi_mem *spimem)
-{
-	struct m25p *flash = spi_mem_get_drvdata(spimem);
-
-	spi_nor_restore(&flash->spi_nor);
-}
-/*
- * Do NOT add to this array without reading the following:
- *
- * Historically, many flash devices are bound to this driver by their name. But
- * since most of these flash are compatible to some extent, and their
- * differences can often be differentiated by the JEDEC read-ID command, we
- * encourage new users to add support to the spi-nor library, and simply bind
- * against a generic string here (e.g., "jedec,spi-nor").
- *
- * Many flash names are kept here in this list (as well as in spi-nor.c) to
- * keep them available as module aliases for existing platforms.
- */
-static const struct spi_device_id m25p_ids[] = {
-	/*
-	 * Allow non-DT platform devices to bind to the "spi-nor" modalias, and
-	 * hack around the fact that the SPI core does not provide uevent
-	 * matching for .of_match_table
-	 */
-	{"spi-nor"},
-
-	/*
-	 * Entries not used in DTs that should be safe to drop after replacing
-	 * them with "spi-nor" in platform data.
-	 */
-	{"s25sl064a"},	{"w25x16"},	{"m25p10"},	{"m25px64"},
-
-	/*
-	 * Entries that were used in DTs without "jedec,spi-nor" fallback and
-	 * should be kept for backward compatibility.
-	 */
-	{"at25df321a"},	{"at25df641"},	{"at26df081a"},
-	{"mx25l4005a"},	{"mx25l1606e"},	{"mx25l6405d"},	{"mx25l12805d"},
-	{"mx25l25635e"},{"mx66l51235l"},
-	{"n25q064"},	{"n25q128a11"},	{"n25q128a13"},	{"n25q512a"},
-	{"s25fl256s1"},	{"s25fl512s"},	{"s25sl12801"},	{"s25fl008k"},
-	{"s25fl064k"},
-	{"sst25vf040b"},{"sst25vf016b"},{"sst25vf032b"},{"sst25wf040"},
-	{"m25p40"},	{"m25p80"},	{"m25p16"},	{"m25p32"},
-	{"m25p64"},	{"m25p128"},
-	{"w25x80"},	{"w25x32"},	{"w25q32"},	{"w25q32dw"},
-	{"w25q80bl"},	{"w25q128"},	{"w25q256"},
-
-	/* Flashes that can't be detected using JEDEC */
-	{"m25p05-nonjedec"},	{"m25p10-nonjedec"},	{"m25p20-nonjedec"},
-	{"m25p40-nonjedec"},	{"m25p80-nonjedec"},	{"m25p16-nonjedec"},
-	{"m25p32-nonjedec"},	{"m25p64-nonjedec"},	{"m25p128-nonjedec"},
-
-	/* Everspin MRAMs (non-JEDEC) */
-	{ "mr25h128" }, /* 128 Kib, 40 MHz */
-	{ "mr25h256" }, /* 256 Kib, 40 MHz */
-	{ "mr25h10" },  /*   1 Mib, 40 MHz */
-	{ "mr25h40" },  /*   4 Mib, 40 MHz */
-
-	{ },
-};
-MODULE_DEVICE_TABLE(spi, m25p_ids);
-
-static const struct of_device_id m25p_of_table[] = {
-	/*
-	 * Generic compatibility for SPI NOR that can be identified by the
-	 * JEDEC READ ID opcode (0x9F). Use this, if possible.
-	 */
-	{ .compatible = "jedec,spi-nor" },
-	{}
-};
-MODULE_DEVICE_TABLE(of, m25p_of_table);
-
-static struct spi_mem_driver m25p80_driver = {
-	.spidrv = {
-		.driver = {
-			.name	= "m25p80",
-			.of_match_table = m25p_of_table,
-		},
-		.id_table	= m25p_ids,
-	},
-	.probe	= m25p_probe,
-	.remove	= m25p_remove,
-	.shutdown	= m25p_shutdown,
-
-	/* REVISIT: many of these chips have deep power-down modes, which
-	 * should clearly be entered on suspend() to minimize power use.
-	 * And also when they're otherwise idle...
-	 */
-};
-
-module_spi_mem_driver(m25p80_driver);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Mike Lavender");
-MODULE_DESCRIPTION("MTD SPI driver for ST M25Pxx flash chips");

drivers/mtd/spi-nor/Kconfig

@@ -2,6 +2,8 @@
 menuconfig MTD_SPI_NOR
 	tristate "SPI-NOR device support"
 	depends on MTD
+	depends on MTD && SPI_MASTER
+	select SPI_MEM
 	help
 	  This is the framework for the SPI NOR which can be used by the SPI
 	  device drivers and the SPI-NOR device driver.

include/linux/mtd/spi-nor.h

@@ -9,6 +9,7 @@
 #include <linux/bitops.h>
 #include <linux/mtd/cfi.h>
 #include <linux/mtd/mtd.h>
+#include <linux/spi/spi-mem.h>
 
 /*
  * Manufacturer IDs
@@ -344,6 +345,7 @@ struct flash_info;
  * @mtd:		point to a mtd_info structure
  * @lock:		the lock for the read/write/erase/lock/unlock operations
  * @dev:		point to a spi device, or a spi nor controller device.
+ * @spimem:		point to the spi mem device
  * @bouncebuf:		bounce buffer used when the buffer passed by the MTD
  *                      layer is not DMA-able
  * @bouncebuf_size:	size of the bounce buffer
@@ -384,6 +386,7 @@ struct spi_nor {
 	struct mtd_info		mtd;
 	struct mutex		lock;
 	struct device		*dev;
+	struct spi_mem		*spimem;
 	u8			*bouncebuf;
 	size_t			bouncebuf_size;
 	const struct flash_info	*info;