diff mbox series

[v2,2/2] mtd: devices: add support for microchip 48l640 EERAM

Message ID 20210529102744.1251220-3-hs@denx.de
State New
Headers show
Series mtd: devices: add support for microchip 48l640 EERAM | expand

Commit Message

Heiko Schocher May 29, 2021, 10:27 a.m. UTC
The Microchip 48l640 is a 8KByte EERAM connected via SPI.

Signed-off-by: Heiko Schocher <hs@denx.de>
Tested-by: Fabio Estevam <festevam@denx.de>
---
I tried to use drivers/mtd/devices/mchp23k256.c but this
driver does not use any status register and there seems
slight differences in registers (no write enable register
for example), so I decided to make a new driver.

This driver sets the continuous mode bit in Status register,
which states you can write continuous ... but after writting
32 bytes the chip goes into an undefined state, so driver now
writes data in 32 byte chunks.

I also tried to use regmap, but it leads in a lot of more code,
and as this chip has only spi interface it makes no sense, or?

Tested  this driver on board imx8mp-phyboard-pollux-rdk
board, which is already in mainline.

Made some tbot tests, which write at random offset random
length bytes with dd and and random content. Reread the data
after a reboot and compare with the written data. Works fine.

Changes in v2:
- fix build warnings
- add Fabios Tested-by

 drivers/mtd/devices/Kconfig      |   6 +
 drivers/mtd/devices/Makefile     |   1 +
 drivers/mtd/devices/mchp48l640.c | 374 +++++++++++++++++++++++++++++++
 3 files changed, 381 insertions(+)
 create mode 100644 drivers/mtd/devices/mchp48l640.c

Comments

kernel test robot May 29, 2021, 12:53 p.m. UTC | #1
Hi Heiko,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on mtd/mtd/next]
[also build test WARNING on mtd/mtd/fixes linux/master linus/master v5.13-rc3 next-20210528]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Heiko-Schocher/mtd-devices-add-support-for-microchip-48l640-EERAM/20210529-182943
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux.git mtd/next
config: arc-allyesconfig (attached as .config)
compiler: arceb-elf-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/eccf3abb95a75cb12c0506c6db8d129b69c71a9c
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Heiko-Schocher/mtd-devices-add-support-for-microchip-48l640-EERAM/20210529-182943
        git checkout eccf3abb95a75cb12c0506c6db8d129b69c71a9c
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   In file included from include/linux/printk.h:409,
                    from include/linux/kernel.h:17,
                    from include/linux/delay.h:22,
                    from drivers/mtd/devices/mchp48l640.c:14:
   drivers/mtd/devices/mchp48l640.c: In function 'mchp48l640_read':
>> drivers/mtd/devices/mchp48l640.c:280:28: warning: format '%ld' expects argument of type 'long int', but argument 4 has type 'size_t' {aka 'unsigned int'} [-Wformat=]
     280 |  dev_dbg(&flash->spi->dev, "read len: %ld from: %llx", len, from);
         |                            ^~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/dynamic_debug.h:129:15: note: in definition of macro '__dynamic_func_call'
     129 |   func(&id, ##__VA_ARGS__);  \
         |               ^~~~~~~~~~~
   include/linux/dynamic_debug.h:161:2: note: in expansion of macro '_dynamic_func_call'
     161 |  _dynamic_func_call(fmt,__dynamic_dev_dbg,   \
         |  ^~~~~~~~~~~~~~~~~~
   include/linux/dev_printk.h:123:2: note: in expansion of macro 'dynamic_dev_dbg'
     123 |  dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |  ^~~~~~~~~~~~~~~
   include/linux/dev_printk.h:123:23: note: in expansion of macro 'dev_fmt'
     123 |  dynamic_dev_dbg(dev, dev_fmt(fmt), ##__VA_ARGS__)
         |                       ^~~~~~~
   drivers/mtd/devices/mchp48l640.c:280:2: note: in expansion of macro 'dev_dbg'
     280 |  dev_dbg(&flash->spi->dev, "read len: %ld from: %llx", len, from);
         |  ^~~~~~~
   drivers/mtd/devices/mchp48l640.c:280:41: note: format string is defined here
     280 |  dev_dbg(&flash->spi->dev, "read len: %ld from: %llx", len, from);
         |                                       ~~^
         |                                         |
         |                                         long int
         |                                       %d


vim +280 drivers/mtd/devices/mchp48l640.c

   265	
   266	static int mchp48l640_read(struct mtd_info *mtd, loff_t from, size_t len,
   267				   size_t *retlen, unsigned char *buf)
   268	{
   269		struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
   270		int ret;
   271		size_t wlen = 0;
   272		loff_t woff = from;
   273		size_t ws;
   274		size_t page_sz = flash->caps->page_size;
   275	
   276		/*
   277		 * we set PRO bit (page rollover), but if read length > page size
   278		 * does result in total chaos in result ...
   279		 */
 > 280		dev_dbg(&flash->spi->dev, "read len: %ld from: %llx", len, from);
   281		while (wlen < len) {
   282			ws = min((len - wlen), page_sz);
   283			ret = mchp48l640_read_page(mtd, woff, ws, retlen, &buf[wlen]);
   284			if (ret)
   285				return ret;
   286			wlen += ws;
   287			woff += ws;
   288		}
   289	
   290		return ret;
   291	};
   292	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
diff mbox series

Patch

diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig
index 0f4c2d823de84..79cb981ececc9 100644
--- a/drivers/mtd/devices/Kconfig
+++ b/drivers/mtd/devices/Kconfig
@@ -89,6 +89,12 @@  config MTD_MCHP23K256
 	  platform data, or a device tree description if you want to
 	  specify device partitioning
 
+config MTD_MCHP48L640
+	tristate "Microchip 48L640 EERAM"
+	depends on SPI_MASTER
+	help
+	  This enables access to Microchip 48L640 EERAM chips, using SPI.
+
 config MTD_SPEAR_SMI
 	tristate "SPEAR MTD NOR Support through SMI controller"
 	depends on PLAT_SPEAR || COMPILE_TEST
diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile
index 991c8d12c0160..0362cf6bdc67f 100644
--- a/drivers/mtd/devices/Makefile
+++ b/drivers/mtd/devices/Makefile
@@ -13,6 +13,7 @@  obj-$(CONFIG_MTD_LART)		+= lart.o
 obj-$(CONFIG_MTD_BLOCK2MTD)	+= block2mtd.o
 obj-$(CONFIG_MTD_DATAFLASH)	+= mtd_dataflash.o
 obj-$(CONFIG_MTD_MCHP23K256)	+= mchp23k256.o
+obj-$(CONFIG_MTD_MCHP48L640)	+= mchp48l640.o
 obj-$(CONFIG_MTD_SPEAR_SMI)	+= spear_smi.o
 obj-$(CONFIG_MTD_SST25L)	+= sst25l.o
 obj-$(CONFIG_MTD_BCM47XXSFLASH)	+= bcm47xxsflash.o
diff --git a/drivers/mtd/devices/mchp48l640.c b/drivers/mtd/devices/mchp48l640.c
new file mode 100644
index 0000000000000..7b29b8c4e6fb2
--- /dev/null
+++ b/drivers/mtd/devices/mchp48l640.c
@@ -0,0 +1,374 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for Microchip 48L640 64 Kb SPI Serial EERAM
+ *
+ * Copyright Heiko Schocher <hs@denx.de>
+ *
+ * datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20006055B.pdf
+ *
+ * we set continuous mode but reading/writing more bytes than
+ * pagesize seems to bring chip into state where readden values
+ * are wrong ... no idea why.
+ *
+ */
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mutex.h>
+#include <linux/sched.h>
+#include <linux/sizes.h>
+#include <linux/spi/flash.h>
+#include <linux/spi/spi.h>
+#include <linux/of_device.h>
+
+struct mchp48_caps {
+	unsigned int size;
+	unsigned int page_size;
+};
+
+struct mchp48l640_flash {
+	struct spi_device	*spi;
+	struct mutex		lock;
+	struct mtd_info		mtd;
+	const struct mchp48_caps	*caps;
+};
+
+#define MCHP48L640_CMD_WREN		0x06
+#define MCHP48L640_CMD_WRDI		0x04
+#define MCHP48L640_CMD_WRITE		0x02
+#define MCHP48L640_CMD_READ		0x03
+#define MCHP48L640_CMD_WRSR		0x01
+#define MCHP48L640_CMD_RDSR		0x05
+
+#define MCHP48L640_STATUS_RDY		0x01
+#define MCHP48L640_STATUS_WEL		0x02
+#define MCHP48L640_STATUS_BP0		0x04
+#define MCHP48L640_STATUS_BP1		0x08
+#define MCHP48L640_STATUS_SWM		0x10
+#define MCHP48L640_STATUS_PRO		0x20
+#define MCHP48L640_STATUS_ASE		0x40
+
+#define MCHP48L640_TIMEOUT		100
+
+#define MAX_CMD_SIZE			0x10
+
+#define to_mchp48l640_flash(x) container_of(x, struct mchp48l640_flash, mtd)
+
+static int mchp48l640_mkcmd(struct mchp48l640_flash *flash, u8 cmd, loff_t addr, char *buf)
+{
+	buf[0] = cmd;
+	buf[1] = addr >> 8;
+	buf[2] = addr;
+
+	return 3;
+}
+
+static int mchp48l640_read_status(struct mchp48l640_flash *flash, int *status)
+{
+	unsigned char cmd[2];
+	int ret;
+
+	cmd[0] = MCHP48L640_CMD_RDSR;
+	cmd[1] = 0x00;
+	mutex_lock(&flash->lock);
+	ret = spi_write_then_read(flash->spi, &cmd[0], 1, &cmd[1], 1);
+	mutex_unlock(&flash->lock);
+	if (!ret)
+		*status = cmd[1];
+	dev_dbg(&flash->spi->dev, "read status ret: %d status: %x", ret, *status);
+
+	return ret;
+}
+
+static int mchp48l640_waitforbit(struct mchp48l640_flash *flash, int bit, bool set)
+{
+	int ret, status;
+	unsigned long deadline;
+
+	deadline = jiffies + msecs_to_jiffies(MCHP48L640_TIMEOUT);
+	do {
+		ret = mchp48l640_read_status(flash, &status);
+		dev_dbg(&flash->spi->dev, "read status ret: %d bit: %x %sset status: %x",
+			ret, bit, (set ? "" : "not"), status);
+		if (ret)
+			return ret;
+
+		if (set) {
+			if ((status & bit) == bit)
+				return 0;
+		} else {
+			if ((status & bit) == 0)
+				return 0;
+		}
+
+		usleep_range(1000, 2000);
+	} while (!time_after_eq(jiffies, deadline));
+
+	dev_err(&flash->spi->dev, "Timeout waiting for bit %x %s set in status register.",
+		bit, (set ? "" : "not"));
+	return -ETIMEDOUT;
+}
+
+static int mchp48l640_write_prepare(struct mchp48l640_flash *flash, bool enable)
+{
+	unsigned char cmd[2];
+	int ret;
+
+	if (enable)
+		cmd[0] = MCHP48L640_CMD_WREN;
+	else
+		cmd[0] = MCHP48L640_CMD_WRDI;
+
+	mutex_lock(&flash->lock);
+	ret = spi_write(flash->spi, cmd, 1);
+	mutex_unlock(&flash->lock);
+
+	if (ret)
+		dev_err(&flash->spi->dev, "write %sable failed ret: %d",
+			(enable ? "en" : "dis"), ret);
+
+	dev_dbg(&flash->spi->dev, "write %sable success ret: %d",
+		(enable ? "en" : "dis"), ret);
+	if (enable)
+		return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_WEL, true);
+
+	return ret;
+}
+
+static int mchp48l640_set_mode(struct mchp48l640_flash *flash)
+{
+	unsigned char cmd[2];
+	int ret;
+
+	ret = mchp48l640_write_prepare(flash, true);
+	if (ret)
+		return ret;
+
+	cmd[0] = MCHP48L640_CMD_WRSR;
+	cmd[1] = MCHP48L640_STATUS_PRO;
+
+	mutex_lock(&flash->lock);
+	ret = spi_write(flash->spi, cmd, 2);
+	mutex_unlock(&flash->lock);
+	if (ret)
+		dev_err(&flash->spi->dev, "Could not set continuous mode ret: %d", ret);
+
+	return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_PRO, true);
+}
+
+static int mchp48l640_wait_rdy(struct mchp48l640_flash *flash)
+{
+	return mchp48l640_waitforbit(flash, MCHP48L640_STATUS_RDY, false);
+};
+
+static int mchp48l640_write_page(struct mtd_info *mtd, loff_t to, size_t len,
+			    size_t *retlen, const unsigned char *buf)
+{
+	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
+	unsigned char *cmd;
+	int ret;
+	int cmdlen;
+
+	cmd = kmalloc((3 + len), GFP_KERNEL | GFP_DMA);
+	if (!cmd)
+		return -ENOMEM;
+
+	ret = mchp48l640_wait_rdy(flash);
+	if (ret)
+		goto fail;
+
+	ret = mchp48l640_write_prepare(flash, true);
+	if (ret)
+		goto fail;
+
+	mutex_lock(&flash->lock);
+	cmdlen = mchp48l640_mkcmd(flash, MCHP48L640_CMD_WRITE, to, cmd);
+	memcpy(&cmd[cmdlen], buf, len);
+	ret = spi_write(flash->spi, cmd, cmdlen + len);
+	mutex_unlock(&flash->lock);
+	if (!ret)
+		*retlen += len;
+	else
+		goto fail;
+
+	ret = mchp48l640_waitforbit(flash, MCHP48L640_STATUS_WEL, false);
+	if (ret)
+		goto fail;
+
+	kfree(cmd);
+	return 0;
+fail:
+	kfree(cmd);
+	dev_err(&flash->spi->dev, "write fail with: %d", ret);
+	return ret;
+};
+
+static int mchp48l640_write(struct mtd_info *mtd, loff_t to, size_t len,
+			    size_t *retlen, const unsigned char *buf)
+{
+	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
+	int ret;
+	size_t wlen = 0;
+	loff_t woff = to;
+	size_t ws;
+	size_t page_sz = flash->caps->page_size;
+
+	/*
+	 * we set PRO bit (page rollover), but writing length > page size
+	 * does result in total chaos, so write in 32 byte chunks.
+	 */
+	while (wlen < len) {
+		ws = min((len - wlen), page_sz);
+		ret = mchp48l640_write_page(mtd, woff, ws, retlen, &buf[wlen]);
+		if (ret)
+			return ret;
+		wlen += ws;
+		woff += ws;
+	}
+
+	return ret;
+}
+
+static int mchp48l640_read_page(struct mtd_info *mtd, loff_t from, size_t len,
+			   size_t *retlen, unsigned char *buf)
+{
+	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
+	unsigned char *cmd;
+	int ret;
+	int cmdlen;
+
+	cmd = kmalloc((3 + len), GFP_KERNEL | GFP_DMA);
+	if (!cmd)
+		return -ENOMEM;
+
+	ret = mchp48l640_wait_rdy(flash);
+	if (ret)
+		goto fail;
+
+	mutex_lock(&flash->lock);
+	cmdlen = mchp48l640_mkcmd(flash, MCHP48L640_CMD_READ, from, cmd);
+	ret = spi_write_then_read(flash->spi, cmd, cmdlen, buf, len);
+	mutex_unlock(&flash->lock);
+	if (!ret)
+		*retlen += len;
+
+	return ret;
+
+fail:
+	kfree(cmd);
+	dev_err(&flash->spi->dev, "read fail with: %d", ret);
+	return ret;
+}
+
+static int mchp48l640_read(struct mtd_info *mtd, loff_t from, size_t len,
+			   size_t *retlen, unsigned char *buf)
+{
+	struct mchp48l640_flash *flash = to_mchp48l640_flash(mtd);
+	int ret;
+	size_t wlen = 0;
+	loff_t woff = from;
+	size_t ws;
+	size_t page_sz = flash->caps->page_size;
+
+	/*
+	 * we set PRO bit (page rollover), but if read length > page size
+	 * does result in total chaos in result ...
+	 */
+	dev_dbg(&flash->spi->dev, "read len: %ld from: %llx", len, from);
+	while (wlen < len) {
+		ws = min((len - wlen), page_sz);
+		ret = mchp48l640_read_page(mtd, woff, ws, retlen, &buf[wlen]);
+		if (ret)
+			return ret;
+		wlen += ws;
+		woff += ws;
+	}
+
+	return ret;
+};
+
+static const struct mchp48_caps mchp48l640_caps = {
+	.size = SZ_8K,
+	.page_size = 32,
+};
+
+static int mchp48l640_probe(struct spi_device *spi)
+{
+	struct mchp48l640_flash *flash;
+	struct flash_platform_data *data;
+	int err;
+	int status;
+
+	flash = devm_kzalloc(&spi->dev, sizeof(*flash), GFP_KERNEL);
+	if (!flash)
+		return -ENOMEM;
+
+	flash->spi = spi;
+	mutex_init(&flash->lock);
+	spi_set_drvdata(spi, flash);
+
+	err = mchp48l640_read_status(flash, &status);
+	if (err)
+		return err;
+
+	err = mchp48l640_set_mode(flash);
+	if (err)
+		return err;
+
+	data = dev_get_platdata(&spi->dev);
+
+	flash->caps = of_device_get_match_data(&spi->dev);
+	if (!flash->caps)
+		flash->caps = &mchp48l640_caps;
+
+	mtd_set_of_node(&flash->mtd, spi->dev.of_node);
+	flash->mtd.dev.parent	= &spi->dev;
+	flash->mtd.type		= MTD_RAM;
+	flash->mtd.flags	= MTD_CAP_RAM;
+	flash->mtd.writesize	= flash->caps->page_size;
+	flash->mtd.size		= flash->caps->size;
+	flash->mtd._read	= mchp48l640_read;
+	flash->mtd._write	= mchp48l640_write;
+
+	err = mtd_device_register(&flash->mtd, data ? data->parts : NULL,
+				  data ? data->nr_parts : 0);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static int mchp48l640_remove(struct spi_device *spi)
+{
+	struct mchp48l640_flash *flash = spi_get_drvdata(spi);
+
+	return mtd_device_unregister(&flash->mtd);
+}
+
+static const struct of_device_id mchp48l640_of_table[] = {
+	{
+		.compatible = "microchip,48l640",
+		.data = &mchp48l640_caps,
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, mchp48l640_of_table);
+
+static struct spi_driver mchp48l640_driver = {
+	.driver = {
+		.name	= "mchp48l640",
+		.of_match_table = of_match_ptr(mchp48l640_of_table),
+	},
+	.probe		= mchp48l640_probe,
+	.remove		= mchp48l640_remove,
+};
+
+module_spi_driver(mchp48l640_driver);
+
+MODULE_DESCRIPTION("MTD SPI driver for Microchip 48l640 EERAM chips");
+MODULE_AUTHOR("Heiko Schocher <hs@denx.de>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("spi:mchp48l640");