omap3: rx51: Add SDRAM init

This patch adds board specific SDRAM init for RX51. This patch is a
collaboration of work from following people:

Juha Yrjola: Original code
Lauri Leukkunen: Port to RX51
Tero Kristo: Support for multiple OPP:s, merge of patches
Samu Onkalo: Fixed SDRAM parameters according to specs
Kalle Jokiniemi: A fix for rounding error

Signed-off-by: Tero Kristo <tero.kristo@nokia.com>
Cc: Samu Onkalo <samu.p.onkalo@nokia.com>
Cc: Kalle Jokiniemi <kalle.jokiniemi@digia.com>
Cc: Lauri Leukkunen <lauri.leukkunen@nokia.com>
Cc: Juha Yrjola <juha.yrjola@solidboot.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

3 files changed, 228 insertions, 1 deletions

diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
index f40619ed7fad..d56fb2b19195 100644
--- a/arch/arm/mach-omap2/Makefile
+++ b/arch/arm/mach-omap2/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_MACH_OMAP_3430SDP)		+= board-3430sdp.o \
                                            mmc-twl4030.o
 obj-$(CONFIG_MACH_NOKIA_N8X0)           += board-n8x0.o
 obj-$(CONFIG_MACH_NOKIA_RX51)           += board-rx51.o \
+                                           board-rx51-sdram.o \
                                            board-rx51-peripherals.o \
                                            mmc-twl4030.o
 obj-$(CONFIG_MACH_OMAP_ZOOM2)           += board-zoom2.o \
diff --git a/arch/arm/mach-omap2/board-rx51-sdram.c b/arch/arm/mach-omap2/board-rx51-sdram.c
new file mode 100644
index 000000000000..f392844195d2
--- /dev/null
+++ b/arch/arm/mach-omap2/board-rx51-sdram.c
@@ -0,0 +1,221 @@
+/*
+ * SDRC register values for RX51
+ *
+ * Copyright (C) 2008 Nokia Corporation
+ *
+ * Lauri Leukkunen <lauri.leukkunen@nokia.com>
+ *
+ * Original code by Juha Yrjola <juha.yrjola@solidboot.com>
+ *
+ * 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/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <plat/io.h>
+#include <plat/common.h>
+#include <plat/clock.h>
+#include <plat/sdrc.h>
+
+
+/* In picoseconds, except for tREF (ns), tXP, tCKE, tWTR (clks) */
+struct sdram_timings {
+        u32 casl;
+        u32 tDAL;
+        u32 tDPL;
+        u32 tRRD;
+        u32 tRCD;
+        u32 tRP;
+        u32 tRAS;
+        u32 tRC;
+        u32 tRFC;
+        u32 tXSR;
+
+        u32 tREF; /* in ns */
+
+        u32 tXP;
+        u32 tCKE;
+        u32 tWTR;
+};
+
+struct omap_sdrc_params rx51_sdrc_params[4];
+
+static const struct sdram_timings rx51_timings[] = {
+        {
+                .casl = 3,
+                .tDAL = 33000,
+                .tDPL = 15000,
+                .tRRD = 12000,
+                .tRCD = 22500,
+                .tRP = 18000,
+                .tRAS = 42000,
+                .tRC = 66000,
+                .tRFC = 138000,
+                .tXSR = 200000,
+
+                .tREF = 7800,
+
+                .tXP = 2,
+                .tCKE = 2,
+                .tWTR = 2
+        },
+};
+
+static unsigned long sdrc_get_fclk_period(long rate)
+{
+        /* In picoseconds */
+        return 1000000000 / rate;
+}
+
+static unsigned int sdrc_ps_to_ticks(unsigned int time_ps, long rate)
+{
+        unsigned long tick_ps;
+
+        /* Calculate in picosecs to yield more exact results */
+        tick_ps = sdrc_get_fclk_period(rate);
+
+        return (time_ps + tick_ps - 1) / tick_ps;
+}
+#undef DEBUG
+#ifdef DEBUG
+static int set_sdrc_timing_regval(u32 *regval, int st_bit, int end_bit,
+                                int ticks, long rate, const char *name)
+#else
+static int set_sdrc_timing_regval(u32 *regval, int st_bit, int end_bit,
+                               int ticks)
+#endif
+{
+        int mask, nr_bits;
+
+        nr_bits = end_bit - st_bit + 1;
+        if (ticks >= 1 << nr_bits)
+                return -1;
+        mask = (1 << nr_bits) - 1;
+        *regval &= ~(mask << st_bit);
+        *regval |= ticks << st_bit;
+#ifdef DEBUG
+        printk(KERN_INFO "SDRC %s: %i ticks %i ns\n", name, ticks,
+                        (unsigned int)sdrc_get_fclk_period(rate) * ticks /
+                        1000);
+#endif
+
+        return 0;
+}
+
+#ifdef DEBUG
+#define SDRC_SET_ONE(reg, st, end, field, rate) \
+        if (set_sdrc_timing_regval((reg), (st), (end), \
+                        rx51_timings->field, (rate), #field) < 0) \
+                err = -1;
+#else
+#define SDRC_SET_ONE(reg, st, end, field, rate) \
+        if (set_sdrc_timing_regval((reg), (st), (end), \
+                        rx51_timings->field) < 0) \
+                err = -1;
+#endif
+
+#ifdef DEBUG
+static int set_sdrc_timing_regval_ps(u32 *regval, int st_bit, int end_bit,
+                                int time, long rate, const char *name)
+#else
+static int set_sdrc_timing_regval_ps(u32 *regval, int st_bit, int end_bit,
+                                int time, long rate)
+#endif
+{
+        int ticks, ret;
+        ret = 0;
+
+        if (time == 0)
+                ticks = 0;
+        else
+                ticks = sdrc_ps_to_ticks(time, rate);
+
+#ifdef DEBUG
+        ret = set_sdrc_timing_regval(regval, st_bit, end_bit, ticks,
+                                     rate, name);
+#else
+        ret = set_sdrc_timing_regval(regval, st_bit, end_bit, ticks);
+#endif
+
+        return ret;
+}
+
+#ifdef DEBUG
+#define SDRC_SET_ONE_PS(reg, st, end, field, rate) \
+        if (set_sdrc_timing_regval_ps((reg), (st), (end), \
+                        rx51_timings->field, \
+                        (rate), #field) < 0) \
+                err = -1;
+
+#else
+#define SDRC_SET_ONE_PS(reg, st, end, field, rate) \
+        if (set_sdrc_timing_regval_ps((reg), (st), (end), \
+                        rx51_timings->field, (rate)) < 0) \
+                err = -1;
+#endif
+
+static int sdrc_timings(int id, long rate)
+{
+        u32 ticks_per_ms;
+        u32 rfr, l;
+        u32 actim_ctrla = 0, actim_ctrlb = 0;
+        u32 rfr_ctrl;
+        int err = 0;
+        long l3_rate = rate / 1000;
+
+        SDRC_SET_ONE_PS(&actim_ctrla,  0,  4, tDAL, l3_rate);
+        SDRC_SET_ONE_PS(&actim_ctrla,  6,  8, tDPL, l3_rate);
+        SDRC_SET_ONE_PS(&actim_ctrla,  9, 11, tRRD, l3_rate);
+        SDRC_SET_ONE_PS(&actim_ctrla, 12, 14, tRCD, l3_rate);
+        SDRC_SET_ONE_PS(&actim_ctrla, 15, 17, tRP, l3_rate);
+        SDRC_SET_ONE_PS(&actim_ctrla, 18, 21, tRAS, l3_rate);
+        SDRC_SET_ONE_PS(&actim_ctrla, 22, 26, tRC, l3_rate);
+        SDRC_SET_ONE_PS(&actim_ctrla, 27, 31, tRFC, l3_rate);
+
+        SDRC_SET_ONE_PS(&actim_ctrlb,  0,  7, tXSR, l3_rate);
+
+        SDRC_SET_ONE(&actim_ctrlb,  8, 10, tXP, l3_rate);
+        SDRC_SET_ONE(&actim_ctrlb, 12, 14, tCKE, l3_rate);
+        SDRC_SET_ONE(&actim_ctrlb, 16, 17, tWTR, l3_rate);
+
+        ticks_per_ms = l3_rate;
+        rfr = rx51_timings[0].tREF * ticks_per_ms / 1000000;
+        if (rfr > 65535 + 50)
+                rfr = 65535;
+        else
+                rfr -= 50;
+
+#ifdef DEBUG
+        printk(KERN_INFO "SDRC tREF: %i ticks\n", rfr);
+#endif
+
+        l = rfr << 8;
+        rfr_ctrl = l | 0x1; /* autorefresh, reload counter with 1xARCV */
+
+        rx51_sdrc_params[id].rate = rate;
+        rx51_sdrc_params[id].actim_ctrla = actim_ctrla;
+        rx51_sdrc_params[id].actim_ctrlb = actim_ctrlb;
+        rx51_sdrc_params[id].rfr_ctrl = rfr_ctrl;
+        rx51_sdrc_params[id].mr = 0x32;
+
+        rx51_sdrc_params[id + 1].rate = 0;
+
+        return err;
+}
+
+struct omap_sdrc_params *rx51_get_sdram_timings(void)
+{
+        int err;
+
+        err = sdrc_timings(0, 41500000);
+        err |= sdrc_timings(1, 83000000);
+        err |= sdrc_timings(2, 166000000);
+
+        return &rx51_sdrc_params[0];
+}
+
diff --git a/arch/arm/mach-omap2/board-rx51.c b/arch/arm/mach-omap2/board-rx51.c
index f1e7e5bbf985..1bb1de245917 100644
--- a/arch/arm/mach-omap2/board-rx51.c
+++ b/arch/arm/mach-omap2/board-rx51.c
@@ -30,6 +30,8 @@
 #include <plat/gpmc.h>
 #include <plat/usb.h>
 
+struct omap_sdrc_params *rx51_get_sdram_timings(void);
+
 static struct omap_lcd_config rx51_lcd_config = {
         .ctrl_name      = "internal",
 };
@@ -55,9 +57,12 @@ static struct omap_board_config_kernel rx51_config[] = {
 
 static void __init rx51_init_irq(void)
 {
+        struct omap_sdrc_params *sdrc_params;
+
         omap_board_config = rx51_config;
         omap_board_config_size = ARRAY_SIZE(rx51_config);
-        omap2_init_common_hw(NULL, NULL);
+        sdrc_params = rx51_get_sdram_timings();
+        omap2_init_common_hw(sdrc_params, sdrc_params);
         omap_init_irq();
         omap_gpio_init();
 }