ARM: OMAP2: Dynamic allocator for GPMC memory space

Add support for assigning memory regions dynamically to peripherals
attached to GPMC interface. Platform specific code should now call
gpmc_cs_request to get a free GPMC memory region instead of using
a fixed address.

Make the H4 and Apollon platform initialization use the new API.

Signed-off-by: Imre Deak <imre.deak@solidboot.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 178 insertions, 2 deletions

diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index c7a48f921fef..f4f04d87df32 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -13,6 +13,8 @@
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/clk.h>
+#include <linux/ioport.h>
+#include <linux/spinlock.h>
 
 #include <asm/io.h>
 #include <asm/arch/gpmc.h>
@@ -41,6 +43,19 @@
 #define GPMC_CS0                0x60
 #define GPMC_CS_SIZE            0x30
 
+#define GPMC_CS_NUM             8
+#define GPMC_MEM_START          0x00000000
+#define GPMC_MEM_END            0x3FFFFFFF
+#define BOOT_ROM_SPACE          0x100000        /* 1MB */
+
+#define GPMC_CHUNK_SHIFT        24              /* 16 MB */
+#define GPMC_SECTION_SHIFT      28              /* 128 MB */
+
+static struct resource  gpmc_mem_root;
+static struct resource  gpmc_cs_mem[GPMC_CS_NUM];
+static spinlock_t       gpmc_mem_lock = SPIN_LOCK_UNLOCKED;
+static unsigned         gpmc_cs_map;
+
 static void __iomem *gpmc_base =
         (void __iomem *) IO_ADDRESS(GPMC_BASE);
 static void __iomem *gpmc_cs_base =
@@ -187,9 +202,168 @@ int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
         return 0;
 }
 
-unsigned long gpmc_cs_get_base_addr(int cs)
+static void gpmc_cs_enable_mem(int cs, u32 base, u32 size)
+{
+        u32 l;
+        u32 mask;
+
+        mask = (1 << GPMC_SECTION_SHIFT) - size;
+        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+        l &= ~0x3f;
+        l = (base >> GPMC_CHUNK_SHIFT) & 0x3f;
+        l &= ~(0x0f << 8);
+        l |= ((mask >> GPMC_CHUNK_SHIFT) & 0x0f) << 8;
+        l |= 1 << 6;            /* CSVALID */
+        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
+}
+
+static void gpmc_cs_disable_mem(int cs)
+{
+        u32 l;
+
+        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+        l &= ~(1 << 6);         /* CSVALID */
+        gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
+}
+
+static void gpmc_cs_get_memconf(int cs, u32 *base, u32 *size)
+{
+        u32 l;
+        u32 mask;
+
+        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+        *base = (l & 0x3f) << GPMC_CHUNK_SHIFT;
+        mask = (l >> 8) & 0x0f;
+        *size = (1 << GPMC_SECTION_SHIFT) - (mask << GPMC_CHUNK_SHIFT);
+}
+
+static int gpmc_cs_mem_enabled(int cs)
+{
+        u32 l;
+
+        l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
+        return l & (1 << 6);
+}
+
+static void gpmc_cs_set_reserved(int cs, int reserved)
 {
-        return (gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7) & 0x1f) << 24;
+        gpmc_cs_map &= ~(1 << cs);
+        gpmc_cs_map |= (reserved ? 1 : 0) << cs;
+}
+
+static int gpmc_cs_reserved(int cs)
+{
+        return gpmc_cs_map & (1 << cs);
+}
+
+static unsigned long gpmc_mem_align(unsigned long size)
+{
+        int order;
+
+        size = (size - 1) >> (GPMC_CHUNK_SHIFT - 1);
+        order = GPMC_CHUNK_SHIFT - 1;
+        do {
+                size >>= 1;
+                order++;
+        } while (size);
+        size = 1 << order;
+        return size;
+}
+
+static int gpmc_cs_insert_mem(int cs, unsigned long base, unsigned long size)
+{
+        struct resource *res = &gpmc_cs_mem[cs];
+        int r;
+
+        size = gpmc_mem_align(size);
+        spin_lock(&gpmc_mem_lock);
+        res->start = base;
+        res->end = base + size - 1;
+        r = request_resource(&gpmc_mem_root, res);
+        spin_unlock(&gpmc_mem_lock);
+
+        return r;
+}
+
+int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
+{
+        struct resource *res = &gpmc_cs_mem[cs];
+        int r = -1;
+
+        if (cs > GPMC_CS_NUM)
+                return -ENODEV;
+
+        size = gpmc_mem_align(size);
+        if (size > (1 << GPMC_SECTION_SHIFT))
+                return -ENOMEM;
+
+        spin_lock(&gpmc_mem_lock);
+        if (gpmc_cs_reserved(cs)) {
+                r = -EBUSY;
+                goto out;
+        }
+        if (gpmc_cs_mem_enabled(cs))
+                r = adjust_resource(res, res->start & ~(size - 1), size);
+        if (r < 0)
+                r = allocate_resource(&gpmc_mem_root, res, size, 0, ~0,
+                                      size, NULL, NULL);
+        if (r < 0)
+                goto out;
+
+        gpmc_cs_enable_mem(cs, res->start, res->end - res->start + 1);
+        *base = res->start;
+        gpmc_cs_set_reserved(cs, 1);
+out:
+        spin_unlock(&gpmc_mem_lock);
+        return r;
+}
+
+void gpmc_cs_free(int cs)
+{
+        spin_lock(&gpmc_mem_lock);
+        if (cs >= GPMC_CS_NUM || !gpmc_cs_reserved(cs)) {
+                printk(KERN_ERR "Trying to free non-reserved GPMC CS%d\n", cs);
+                BUG();
+                spin_unlock(&gpmc_mem_lock);
+                return;
+        }
+        gpmc_cs_disable_mem(cs);
+        release_resource(&gpmc_cs_mem[cs]);
+        gpmc_cs_set_reserved(cs, 0);
+        spin_unlock(&gpmc_mem_lock);
+}
+
+void __init gpmc_mem_init(void)
+{
+        int cs;
+        unsigned long boot_rom_space = 0;
+
+        if (cpu_is_omap242x()) {
+                u32 l;
+                l = omap_readl(OMAP242X_CONTROL_STATUS);
+                /* In case of internal boot the 1st MB is redirected to the
+                 * boot ROM memory space.
+                 */
+                if (l & (1 << 3))
+                        boot_rom_space = BOOT_ROM_SPACE;
+        } else
+                /* We assume internal boot if the mode can't be
+                 * determined.
+                 */
+                boot_rom_space = BOOT_ROM_SPACE;
+        gpmc_mem_root.start = GPMC_MEM_START + boot_rom_space;
+        gpmc_mem_root.end = GPMC_MEM_END;
+
+        /* Reserve all regions that has been set up by bootloader */
+        for (cs = 0; cs < GPMC_CS_NUM; cs++) {
+                u32 base, size;
+
+                if (!gpmc_cs_mem_enabled(cs))
+                        continue;
+                gpmc_cs_get_memconf(cs, &base, &size);
+                if (gpmc_cs_insert_mem(cs, base, size) < 0)
+                        BUG();
+        }
 }
 
 void __init gpmc_init(void)
@@ -206,4 +380,6 @@ void __init gpmc_init(void)
         l &= 0x03 << 3;
         l |= (0x02 << 3) | (1 << 0);
         gpmc_write_reg(GPMC_SYSCONFIG, l);
+
+        gpmc_mem_init();
 }