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>

2 files changed, 180 insertions, 4 deletions

diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index c7a48f921fe..f4f04d87df3 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();
 }
diff --git a/include/asm-arm/arch-omap/gpmc.h b/include/asm-arm/arch-omap/gpmc.h
index 1a0a5207822..7c03ef6c14c 100644
--- a/include/asm-arm/arch-omap/gpmc.h
+++ b/include/asm-arm/arch-omap/gpmc.h
@@ -85,7 +85,7 @@ extern void gpmc_cs_write_reg(int cs, int idx, u32 val);
 extern u32 gpmc_cs_read_reg(int cs, int idx);
 extern int gpmc_cs_calc_divider(int cs, unsigned int sync_clk);
 extern int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t);
-extern unsigned long gpmc_cs_get_base_addr(int cs);
-
+extern int gpmc_cs_request(int cs, unsigned long size, unsigned long *base);
+extern void gpmc_cs_free(int cs);
 
 #endif