ARM: OMAP: Add GPMC support for OMAP2

Implement basic support for General-Purpose Memory Controller
as found on OMAP2420.

Dynamic CS address space allocation still needs to be done.

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

1 files changed, 209 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
new file mode 100644
index 00000000000..4aeaa4e7958
--- /dev/null
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -0,0 +1,209 @@
+/*
+ * GPMC support functions
+ *
+ * Copyright (C) 2005-2006 Nokia Corporation
+ *
+ * Author: Juha Yrjola
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+
+#include <asm/io.h>
+#include <asm/arch/gpmc.h>
+
+#undef DEBUG
+
+#define GPMC_BASE		0x6800a000
+#define GPMC_REVISION		0x00
+#define GPMC_SYSCONFIG		0x10
+#define GPMC_SYSSTATUS		0x14
+#define GPMC_IRQSTATUS		0x18
+#define GPMC_IRQENABLE		0x1c
+#define GPMC_TIMEOUT_CONTROL	0x40
+#define GPMC_ERR_ADDRESS	0x44
+#define GPMC_ERR_TYPE		0x48
+#define GPMC_CONFIG		0x50
+#define GPMC_STATUS		0x54
+#define GPMC_PREFETCH_CONFIG1	0x1e0
+#define GPMC_PREFETCH_CONFIG2	0x1e4
+#define GPMC_PREFETCH_CONTROL	0x1e8
+#define GPMC_PREFETCH_STATUS	0x1f0
+#define GPMC_ECC_CONFIG		0x1f4
+#define GPMC_ECC_CONTROL	0x1f8
+#define GPMC_ECC_SIZE_CONFIG	0x1fc
+
+#define GPMC_CS0		0x60
+#define GPMC_CS_SIZE		0x30
+
+static void __iomem *gpmc_base =
+	(void __iomem *) IO_ADDRESS(GPMC_BASE);
+static void __iomem *gpmc_cs_base =
+	(void __iomem *) IO_ADDRESS(GPMC_BASE) + GPMC_CS0;
+
+static struct clk *gpmc_l3_clk;
+
+static void gpmc_write_reg(int idx, u32 val)
+{
+	__raw_writel(val, gpmc_base + idx);
+}
+
+static u32 gpmc_read_reg(int idx)
+{
+	return __raw_readl(gpmc_base + idx);
+}
+
+void gpmc_cs_write_reg(int cs, int idx, u32 val)
+{
+	void __iomem *reg_addr;
+
+	reg_addr = gpmc_cs_base + (cs * GPMC_CS_SIZE) + idx;
+	__raw_writel(val, reg_addr);
+}
+
+u32 gpmc_cs_read_reg(int cs, int idx)
+{
+	return __raw_readl(gpmc_cs_base + (cs * GPMC_CS_SIZE) + idx);
+}
+
+/* TODO: Add support for gpmc_fck to clock framework and use it */
+static unsigned long gpmc_get_fclk_period(void)
+{
+	/* In picoseconds */
+	return 1000000000 / ((clk_get_rate(gpmc_l3_clk)) / 1000);
+}
+
+unsigned int gpmc_ns_to_ticks(unsigned int time_ns)
+{
+	unsigned long tick_ps;
+
+	/* Calculate in picosecs to yield more exact results */
+	tick_ps = gpmc_get_fclk_period();
+
+	return (time_ns * 1000 + tick_ps - 1) / tick_ps;
+}
+
+#ifdef DEBUG
+static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
+			       int time, int div, const char *name)
+#else
+static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit,
+			       int time)
+#endif
+{
+	u32 l;
+	int ticks, mask, nr_bits;
+
+	if (time == 0)
+		ticks = 0;
+	else
+		ticks = gpmc_ns_to_ticks(time);
+	nr_bits = end_bit - st_bit + 1;
+	if (ticks >= 1 << nr_bits)
+		return -1;
+
+	mask = (1 << nr_bits) - 1;
+	l = gpmc_cs_read_reg(cs, reg);
+#ifdef DEBUG
+	printk(KERN_INFO "GPMC CS%d: %-10s: %d ticks, %3lu ns (was %i ticks)\n",
+	       cs, name, ticks, gpmc_get_clk_period(div) * ticks / 1000,
+	       (l >> st_bit) & mask);
+#endif
+	l &= ~(mask << st_bit);
+	l |= ticks << st_bit;
+	gpmc_cs_write_reg(cs, reg, l);
+
+	return 0;
+}
+
+#ifdef DEBUG
+#define GPMC_SET_ONE(reg, st, end, field) \
+	if (set_gpmc_timing_reg(cs, (reg), (st), (end),		\
+			t->field, #field) < 0)			\
+		return -1
+#else
+#define GPMC_SET_ONE(reg, st, end, field) \
+	if (set_gpmc_timing_reg(cs, (reg), (st), (end), t->field) < 0) \
+		return -1
+#endif
+
+int gpmc_cs_calc_divider(int cs, unsigned int sync_clk)
+{
+	int div;
+	u32 l;
+
+	l = sync_clk * 1000 + (gpmc_get_fclk_period() - 1);
+	div = l / gpmc_get_fclk_period();
+	if (div > 4)
+		return -1;
+	if (div < 0)
+		div = 1;
+
+	return div;
+}
+
+int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
+{
+	int div;
+	u32 l;
+
+	div = gpmc_cs_calc_divider(cs, t->sync_clk);
+	if (div < 0)
+		return -1;
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG2,  0,  3, cs_on);
+	GPMC_SET_ONE(GPMC_CS_CONFIG2,  8, 12, cs_rd_off);
+	GPMC_SET_ONE(GPMC_CS_CONFIG2, 16, 20, cs_wr_off);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG3,  0,  3, adv_on);
+	GPMC_SET_ONE(GPMC_CS_CONFIG3,  8, 12, adv_rd_off);
+	GPMC_SET_ONE(GPMC_CS_CONFIG3, 16, 20, adv_wr_off);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG4,  0,  3, oe_on);
+	GPMC_SET_ONE(GPMC_CS_CONFIG4,  8, 12, oe_off);
+	GPMC_SET_ONE(GPMC_CS_CONFIG4, 16, 19, we_on);
+	GPMC_SET_ONE(GPMC_CS_CONFIG4, 24, 28, we_off);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG5,  0,  4, rd_cycle);
+	GPMC_SET_ONE(GPMC_CS_CONFIG5,  8, 12, wr_cycle);
+	GPMC_SET_ONE(GPMC_CS_CONFIG5, 16, 20, access);
+
+	GPMC_SET_ONE(GPMC_CS_CONFIG5, 24, 27, page_burst_access);
+
+#ifdef DEBUG
+	printk(KERN_INFO "GPMC CLK period is %d (div %d)\n",
+	       cs, get_gpmc_clk_period(div), div);
+#endif
+
+	l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1);
+	l &= ~0x03;
+	l |= (div - 1);
+
+	return 0;
+}
+
+unsigned long gpmc_cs_get_base_addr(int cs)
+{
+	return (gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7) & 0x1f) << 24;
+}
+
+void __init gpmc_init(void)
+{
+	u32 l;
+
+	gpmc_l3_clk = clk_get(NULL, "core_l3_ck");
+	BUG_ON(IS_ERR(gpmc_l3_clk));
+
+	l = gpmc_read_reg(GPMC_REVISION);
+	printk(KERN_INFO "GPMC revision %d.%d\n", (l >> 4) & 0x0f, l & 0x0f);
+	/* Set smart idle mode and automatic L3 clock gating */
+	l = gpmc_read_reg(GPMC_SYSCONFIG);
+	l &= 0x03 << 3;
+	l |= (0x02 << 3) | (1 << 0);
+	gpmc_write_reg(GPMC_SYSCONFIG, l);
+}