diff options
Diffstat (limited to 'arch/arm/mach-omap2/board-rx51-sdram.c')
| -rw-r--r-- | arch/arm/mach-omap2/board-rx51-sdram.c | 221 |
1 files changed, 221 insertions, 0 deletions
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 00000000000..f392844195d --- /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]; +} + |