[PATCH] add pismo support
Russell King - ARM Linux
linux at arm.linux.org.uk
Sun Nov 29 09:26:56 EST 2009
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 at 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(+)
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, ®ion);
+ break;
+ case 3:
+ /* static RAM */
+ pismo_add_sram(pismo, i, ®ion);
+ 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 at 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
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