Patchwork add pismo support

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Submitter Russell King - ARM Linux
Date Nov. 29, 2009, 2:56 p.m.
Message ID <20091129145623.GD11445@n2100.arm.linux.org.uk>
Download mbox | patch
Permalink /patch/39730/
State New, archived
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Comments

Russell King - ARM Linux - Nov. 29, 2009, 2:56 p.m.
The following patch adds support for PISMO modules found on ARM Ltd
development platforms.  These are MTD modules, and can have a
selection of SRAM, flash or DOC devices as described by an on-board
I2C EEPROM.

We support SRAM and NOR flash devices only by registering appropriate
conventional MTD platform devices as children of the 'pismo' device.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
--
 drivers/mtd/maps/Kconfig  |   15 ++
 drivers/mtd/maps/Makefile |    1 
 drivers/mtd/maps/pismo.c  |  325 ++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mtd/pismo.h |   17 ++
 4 files changed, 358 insertions(+)
Mike Frysinger - Nov. 29, 2009, 3:12 p.m.
On Sun, Nov 29, 2009 at 09:56, Russell King - ARM Linux wrote:
> --- a/drivers/mtd/maps/Kconfig
> +++ b/drivers/mtd/maps/Kconfig
> +config MTD_PISMO
> +       tristate "MTD discovery driver for PISMO modules"
> +       depends on I2C
> +       depends on ARCH_VERSATILE
> +       help
> +         This driver allows for discovery of PISMO modules - see
> +         <http://www.pismoworld.org/>.  These are small modules containing
> +         up to five memory devices (eg, SRAM, flash, DOC) described by an
> +         I2C EEPROM.
> +
> +         This driver does not create any MTD maps itself; instead it
> +         creates MTD physmap and MTD SRAM platform devices.  If you
> +         enable this option, you should consider enabling MTD_PHYSMAP
> +         and/or MTD_PLATRAM according to the devices on your module.

a sentence telling the module name when built as a module would be good

> +static unsigned int pismo_width_to_bytes(unsigned int width)
> +static int pismo_eeprom_read(struct i2c_client *client, void *buf, u8 addr,
> +       size_t size)
> +static int pismo_add_device(struct pismo_data *pismo, int i,
> +       struct pismo_mem *region, const char *name, void *pdata, size_t psize)
> +static int pismo_add_nor(struct pismo_data *pismo, int i,
> +       struct pismo_mem *region)
> +static int pismo_add_sram(struct pismo_data *pismo, int i,
> +       struct pismo_mem *region)
> +static void pismo_add_one(struct pismo_data *pismo, int i,
> +       const struct pismo_cs_block *cs, phys_addr_t base)
> +static int __devinit pismo_probe(struct i2c_client *client,
> +                                const struct i2c_device_id *id)

all should be __devinit since they're only called by pismo_probe()

> +static int pismo_init(void)

__init

> +       if (sizeof(struct pismo_cs_block) != 48) {
> +               pr_err("BUG: PISMO: sizeof(struct pismo_cs_block) wrong\n");
> +               return -EINVAL;
> +       }
> +       if (sizeof(struct pismo_eeprom) != 256) {
> +               pr_err("BUG: PISMO: sizeof(struct pismo_eeprom) wrong\n");
> +               return -EINVAL;
> +       }

BUILD_BUG()
-mike

Patch

diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index 0b98654..631b060 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -553,4 +553,19 @@  config MTD_VMU
 	  To build this as a module select M here, the module will be called
 	  vmu-flash.
 
+config MTD_PISMO
+	tristate "MTD discovery driver for PISMO modules"
+	depends on I2C
+	depends on ARCH_VERSATILE
+	help
+	  This driver allows for discovery of PISMO modules - see
+	  <http://www.pismoworld.org/>.  These are small modules containing
+	  up to five memory devices (eg, SRAM, flash, DOC) described by an
+	  I2C EEPROM.
+
+	  This driver does not create any MTD maps itself; instead it
+	  creates MTD physmap and MTD SRAM platform devices.  If you
+	  enable this option, you should consider enabling MTD_PHYSMAP
+	  and/or MTD_PLATRAM according to the devices on your module.
+
 endmenu
diff --git a/drivers/mtd/maps/Makefile b/drivers/mtd/maps/Makefile
index 8bae7f9..cffaaf1 100644
--- a/drivers/mtd/maps/Makefile
+++ b/drivers/mtd/maps/Makefile
@@ -61,3 +61,4 @@  obj-$(CONFIG_MTD_INTEL_VR_NOR)	+= intel_vr_nor.o
 obj-$(CONFIG_MTD_BFIN_ASYNC)	+= bfin-async-flash.o
 obj-$(CONFIG_MTD_RBTX4939)	+= rbtx4939-flash.o
 obj-$(CONFIG_MTD_VMU)		+= vmu-flash.o
+obj-$(CONFIG_MTD_PISMO)		+= pismo.o
--- /dev/null	2009-08-03 10:19:25.737008066 +0100
+++ b/drivers/mtd/maps/pismo.c	2009-08-03 14:23:32.000000000 +0100
@@ -0,0 +1,325 @@ 
+/*
+ * PISMO memory driver - http://www.pismoworld.org/
+ *
+ * For ARM Realview and Versatile platforms
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ */
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/mtd/physmap.h>
+#include <linux/mtd/plat-ram.h>
+#include <linux/mtd/pismo.h>
+
+#define PISMO_NUM_CS	5
+
+struct pismo_cs_block {
+	u8	type;
+	u8	width;
+	__le16	access;
+	__le32	size;
+	u32	reserved[2];
+	char	device[32];
+} __packed;
+
+struct pismo_eeprom {
+	struct pismo_cs_block cs[PISMO_NUM_CS];
+	char	board[15];
+	u8	sum;
+} __packed;
+
+struct pismo_mem {
+	phys_addr_t base;
+	u32	size;
+	u16	access;
+	u8	width;
+	u8	type;
+};
+
+struct pismo_data {
+	struct i2c_client	*client;
+	void			(*vpp)(void *, int);
+	void			*vpp_data;
+	struct platform_device	*dev[PISMO_NUM_CS];
+};
+
+/* FIXME: set_vpp could do with a better calling convention */
+static struct pismo_data *vpp_pismo;
+static DEFINE_MUTEX(pismo_mutex);
+
+static int pismo_setvpp_probe_fix(struct pismo_data *pismo)
+{
+	mutex_lock(&pismo_mutex);
+	if (vpp_pismo) {
+		mutex_unlock(&pismo_mutex);
+		kfree(pismo);
+		return -EBUSY;
+	}
+	vpp_pismo = pismo;
+	mutex_unlock(&pismo_mutex);
+	return 0;
+}
+
+static void pismo_setvpp_remove_fix(struct pismo_data *pismo)
+{
+	mutex_lock(&pismo_mutex);
+	if (vpp_pismo == pismo)
+		vpp_pismo = NULL;
+	mutex_unlock(&pismo_mutex);
+}
+
+static void pismo_set_vpp(struct map_info *map, int on)
+{
+	struct pismo_data *pismo = vpp_pismo;
+
+	pismo->vpp(pismo->vpp_data, on);
+}
+/* end of hack */
+
+
+static unsigned int pismo_width_to_bytes(unsigned int width)
+{
+	width &= 15;
+	if (width > 2)
+		return 0;
+	return 1 << width;
+}
+
+static int pismo_eeprom_read(struct i2c_client *client, void *buf, u8 addr,
+	size_t size)
+{
+	int ret;
+	struct i2c_msg msg[] = {
+		{
+			.addr = client->addr,
+			.len = sizeof(addr),
+			.buf = &addr,
+		}, {
+			.addr = client->addr,
+			.flags = I2C_M_RD,
+			.len = size,
+			.buf = buf,
+		},
+	};
+
+	ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
+
+	return ret == ARRAY_SIZE(msg) ? size : -EIO;
+}
+
+static int pismo_add_device(struct pismo_data *pismo, int i,
+	struct pismo_mem *region, const char *name, void *pdata, size_t psize)
+{
+	struct platform_device *dev;
+	struct resource res = { };
+	phys_addr_t base = region.base;
+	int ret;
+
+	if (base == ~0)
+		return -ENXIO;
+
+	res.start = base;
+	res.end = base + region->size - 1;
+	res.flags = IORESOURCE_MEM;
+
+	dev = platform_device_alloc(name, i);
+	if (!dev)
+		return -ENOMEM;
+	dev->dev.parent = &pismo->client->dev;
+
+	do {
+		ret = platform_device_add_resources(dev, &res, 1);
+		if (ret)
+			break;
+
+		ret = platform_device_add_data(dev, pdata, psize);
+		if (ret)
+			break;
+
+		ret = platform_device_add(dev);
+		if (ret)
+			break;
+
+		pismo->dev[i] = dev;
+		return 0;
+	} while (0);
+
+	platform_device_put(dev);
+	return ret;
+}
+
+static int pismo_add_nor(struct pismo_data *pismo, int i,
+	struct pismo_mem *region)
+{
+	struct physmap_flash_data data = {
+		.width = region->width,
+	};
+
+	if (pismo->vpp)
+		data.set_vpp = pismo_set_vpp;
+
+	return pismo_add_device(pismo, i, region, "physmap-flash",
+		&data, sizeof(data));
+}
+
+static int pismo_add_sram(struct pismo_data *pismo, int i,
+	struct pismo_mem *region)
+{
+	struct platdata_mtd_ram data = {
+		.bankwidth = region->width,
+	};
+
+	return pismo_add_device(pismo, i, region, "mtd-ram",
+		&data, sizeof(data));
+}
+
+static void pismo_add_one(struct pismo_data *pismo, int i,
+	const struct pismo_cs_block *cs, phys_addr_t base)
+{
+	struct device *dev = &pismo->client->dev;
+	struct pismo_mem region;
+
+	region.base = base;
+	region.type = cs->type;
+	region.width = pismo_width_to_bytes(cs->width);
+	region.access = le16_to_cpu(cs->access);
+	region.size = le32_to_cpu(cs->size);
+
+	if (region.width == 0) {
+		dev_err(dev, "cs%u: bad width: %02x, ignoring\n", i, cs->width);
+		return;
+	}
+
+	/*
+	 * FIXME: may need to the platforms memory controller here, but at
+	 * the moment we assume that it has already been correctly setup.
+	 * The memory controller can also tell us the base address as well.
+	 */
+
+	dev_info(dev, "cs%u: %.32s: type %02x access %u00ps size %uK\n",
+		i, cs->device, region.type, region.access, region.size / 1024);
+
+	switch (region.type) {
+	case 0:
+		break;
+	case 1:
+		/* static DOC */
+		break;
+	case 2:
+		/* static NOR */
+		pismo_add_nor(pismo, i, &region);
+		break;
+	case 3:
+		/* static RAM */
+		pismo_add_sram(pismo, i, &region);
+		break;
+	}
+}
+
+static int __devexit pismo_remove(struct i2c_client *client)
+{
+	struct pismo_data *pismo = i2c_get_clientdata(client);
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(pismo->dev); i++)
+		platform_device_unregister(pismo->dev[i]);
+
+	/* FIXME: set_vpp needs saner arguments */
+	pismo_setvpp_remove_fix(pismo);
+
+	kfree(pismo);
+
+	return 0;
+}
+
+static int __devinit pismo_probe(struct i2c_client *client,
+				 const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct pismo_pdata *pdata = client->dev.platform_data;
+	struct pismo_eeprom eeprom;
+	struct pismo_data *pismo;
+	int ret, i;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev, "functionality mismatch\n");
+		return -EIO;
+	}
+
+	pismo = kzalloc(sizeof(*pismo), GFP_KERNEL);
+	if (!pismo)
+		return -ENOMEM;
+
+	/* FIXME: set_vpp needs saner arguments */
+	ret = pismo_setvpp_probe_fix(pismo);
+	if (ret)
+		return ret;
+
+	pismo->client = client;
+	if (pdata) {
+		pismo->vpp = pdata->set_vpp;
+		pismo->vpp_data = pdata->vpp_data;
+	}
+	i2c_set_clientdata(client, pismo);
+
+	ret = pismo_eeprom_read(client, &eeprom, 0, sizeof(eeprom));
+	if (ret < 0) {
+		dev_err(&client->dev, "error reading EEPROM: %d\n", ret);
+		return ret;
+	}
+
+	dev_info(&client->dev, "%.15s board found\n", eeprom.board);
+
+	for (i = 0; i < ARRAY_SIZE(eeprom.cs); i++)
+		if (eeprom.cs[i].type != 0xff)
+			pismo_add_one(pismo, i, &eeprom.cs[i],
+				      pdata->cs_addrs[i]);
+
+	return 0;
+}
+
+static const struct i2c_device_id pismo_id[] = {
+	{ "pismo" },
+	{ },
+};
+MODULE_DEVICE_TABLE(i2c, pismo_id);
+
+static struct i2c_driver pismo_driver = {
+	.driver	= {
+		.name	= "pismo",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= pismo_probe,
+	.remove		= __devexit_p(pismo_remove),
+	.id_table	= pismo_id,
+};
+
+static int pismo_init(void)
+{
+	if (sizeof(struct pismo_cs_block) != 48) {
+		pr_err("BUG: PISMO: sizeof(struct pismo_cs_block) wrong\n");
+		return -EINVAL;
+	}
+	if (sizeof(struct pismo_eeprom) != 256) {
+		pr_err("BUG: PISMO: sizeof(struct pismo_eeprom) wrong\n");
+		return -EINVAL;
+	}
+	return i2c_add_driver(&pismo_driver);
+}
+module_init(pismo_init);
+
+static void __exit pismo_exit(void)
+{
+	i2c_del_driver(&pismo_driver);
+}
+module_exit(pismo_exit);
+
+MODULE_AUTHOR("Russell King <linux@arm.linux.org.uk>");
+MODULE_DESCRIPTION("PISMO memory driver");
+MODULE_LICENSE("GPL");
--- /dev/null	2009-08-03 10:19:25.737008066 +0100
+++ b/include/linux/mtd/pismo.h	2009-07-18 10:32:59.000000000 +0100
@@ -0,0 +1,17 @@ 
+/*
+ * PISMO memory driver - http://www.pismoworld.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ */
+#ifndef __LINUX_MTD_PISMO_H
+#define __LINUX_MTD_PISMO_H
+
+struct pismo_pdata {
+	void			(*set_vpp)(void *, int);
+	void			*vpp_data;
+	phys_addr_t		cs_addrs[5];
+};
+
+#endif