3 files changed, 354 insertions, 0 deletions

diff --git a/drivers/mtd/maps/Kconfig b/drivers/mtd/maps/Kconfig
index 4c364d44ad59..2de0cc823d60 100644
--- a/drivers/mtd/maps/Kconfig
+++ b/drivers/mtd/maps/Kconfig
@@ -549,4 +549,21 @@ 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.
+
+          When built as a module, it will be called pismo.ko
+
 endmenu
diff --git a/drivers/mtd/maps/pismo.c b/drivers/mtd/maps/pismo.c
new file mode 100644
index 000000000000..c48cad271f5d
--- /dev/null
+++ b/drivers/mtd/maps/pismo.c
@@ -0,0 +1,320 @@
+/*
+ * 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 __devinit pismo_width_to_bytes(unsigned int width)
+{
+        width &= 15;
+        if (width > 2)
+                return 0;
+        return 1 << width;
+}
+
+static int __devinit 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 __devinit 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 __devinit 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 __devinit 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 __devinit 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 __init pismo_init(void)
+{
+        BUILD_BUG_ON(sizeof(struct pismo_cs_block) != 48);
+        BUILD_BUG_ON(sizeof(struct pismo_eeprom) != 256);
+
+        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");
diff --git a/include/linux/mtd/pismo.h b/include/linux/mtd/pismo.h
new file mode 100644
index 000000000000..8dfb7e1421c5
--- /dev/null
+++ b/include/linux/mtd/pismo.h
@@ -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