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author | Robert ABEL <rabel@cit-ec.uni-bielefeld.de> | 2015-02-27 16:56:54 +0100 |
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committer | Roger Quadros <rogerq@ti.com> | 2015-03-06 12:46:06 +0200 |
commit | 7f2e8c58ae9e35240e5924c63163c07a506d0d12 (patch) | |
tree | 27c51437df1950442adeec4d0c47a153d04b58f1 /drivers/memory/omap-gpmc.c | |
parent | 2e67690137f3a7bac660edd548f8846709c55381 (diff) | |
download | linux-stable-7f2e8c58ae9e35240e5924c63163c07a506d0d12.tar.gz linux-stable-7f2e8c58ae9e35240e5924c63163c07a506d0d12.tar.bz2 linux-stable-7f2e8c58ae9e35240e5924c63163c07a506d0d12.zip |
ARM OMAP2+ GPMC: fix WAITMONITORINGTIME divider bug
The WAITMONITORINGTIME is expressed as a number of GPMC_CLK clock cycles,
even though the access is defined as asynchronous, and no GPMC_CLK clock
is provided to the external device. Still, GPMCFCLKDIVIDER is used as a divider
for the GPMC clock, so it must be programmed to define the
correct WAITMONITORINGTIME delay.
This patch correctly computes WAITMONITORINGTIME in GPMC_CLK cycles instead of GPMC_FCLK cycles,
both during programming (gpmc_cs_set_timings) and during retrieval (gpmc_cs_show_timings).
Signed-off-by: Robert ABEL <rabel@cit-ec.uni-bielefeld.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Diffstat (limited to 'drivers/memory/omap-gpmc.c')
-rw-r--r-- | drivers/memory/omap-gpmc.c | 130 |
1 files changed, 103 insertions, 27 deletions
diff --git a/drivers/memory/omap-gpmc.c b/drivers/memory/omap-gpmc.c index 768bab233196..6c076b7c9b6f 100644 --- a/drivers/memory/omap-gpmc.c +++ b/drivers/memory/omap-gpmc.c @@ -179,6 +179,11 @@ */ #define GPMC_NR_IRQ 2 +enum gpmc_clk_domain { + GPMC_CD_FCLK, + GPMC_CD_CLK +}; + struct gpmc_cs_data { const char *name; @@ -277,16 +282,55 @@ static unsigned long gpmc_get_fclk_period(void) return rate; } -static unsigned int gpmc_ns_to_ticks(unsigned int time_ns) +/** + * gpmc_get_clk_period - get period of selected clock domain in ps + * @cs Chip Select Region. + * @cd Clock Domain. + * + * GPMC_CS_CONFIG1 GPMCFCLKDIVIDER for cs has to be setup + * prior to calling this function with GPMC_CD_CLK. + */ +static unsigned long gpmc_get_clk_period(int cs, enum gpmc_clk_domain cd) +{ + + unsigned long tick_ps = gpmc_get_fclk_period(); + u32 l; + int div; + + switch (cd) { + case GPMC_CD_CLK: + /* get current clk divider */ + l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1); + div = (l & 0x03) + 1; + /* get GPMC_CLK period */ + tick_ps *= div; + break; + case GPMC_CD_FCLK: + /* FALL-THROUGH */ + default: + break; + } + + return tick_ps; + +} + +static unsigned int gpmc_ns_to_clk_ticks(unsigned int time_ns, int cs, + enum gpmc_clk_domain cd) { unsigned long tick_ps; /* Calculate in picosecs to yield more exact results */ - tick_ps = gpmc_get_fclk_period(); + tick_ps = gpmc_get_clk_period(cs, cd); return (time_ns * 1000 + tick_ps - 1) / tick_ps; } +static unsigned int gpmc_ns_to_ticks(unsigned int time_ns) +{ + return gpmc_ns_to_clk_ticks(time_ns, /* any CS */ 0, GPMC_CD_FCLK); +} + static unsigned int gpmc_ps_to_ticks(unsigned int time_ps) { unsigned long tick_ps; @@ -297,9 +341,15 @@ static unsigned int gpmc_ps_to_ticks(unsigned int time_ps) return (time_ps + tick_ps - 1) / tick_ps; } +unsigned int gpmc_clk_ticks_to_ns(unsigned ticks, int cs, + enum gpmc_clk_domain cd) +{ + return ticks * gpmc_get_clk_period(cs, cd) / 1000; +} + unsigned int gpmc_ticks_to_ns(unsigned int ticks) { - return ticks * gpmc_get_fclk_period() / 1000; + return gpmc_clk_ticks_to_ns(ticks, /* any CS */ 0, GPMC_CD_FCLK); } static unsigned int gpmc_ticks_to_ps(unsigned int ticks) @@ -355,18 +405,24 @@ static void gpmc_cs_bool_timings(int cs, const struct gpmc_bool_timings *p) * @st_bit: Start Bit * @end_bit: End Bit. Must be >= @st_bit. * @name: DTS node name, w/o "gpmc," + * @cd: Clock Domain of timing parameter. + * @shift: Parameter value left shifts @shift, which is then printed instead of value. * @raw: Raw Format Option. * raw format: gpmc,name = <value> * tick format: gpmc,name = <value> /‍* x ns -- y ns; x ticks *‍/ * Where x ns -- y ns result in the same tick value. * @noval: Parameter values equal to 0 are not printed. - * @shift: Parameter value left shifts @shift, which is then printed instead of value. * @return: Specified timing parameter (after optional @shift). * */ -static int get_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, - bool raw, bool noval, int shift, - const char *name) +static int get_gpmc_timing_reg( + /* timing specifiers */ + int cs, int reg, int st_bit, int end_bit, + const char *name, const enum gpmc_clk_domain cd, + /* value transform */ + int shift, + /* format specifiers */ + bool raw, bool noval) { u32 l; int nr_bits; @@ -386,8 +442,8 @@ static int get_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, unsigned int time_ns_min = 0; if (l) - time_ns_min = gpmc_ticks_to_ns(l - 1) + 1; - time_ns = gpmc_ticks_to_ns(l); + time_ns_min = gpmc_clk_ticks_to_ns(l - 1, cs, cd) + 1; + time_ns = gpmc_clk_ticks_to_ns(l, cs, cd); pr_info("gpmc,%s = <%u> /* %u ns - %u ns; %i ticks */\n", name, time_ns, time_ns_min, time_ns, l); } else { @@ -402,13 +458,15 @@ static int get_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, pr_info("cs%i %s: 0x%08x\n", cs, #config, \ gpmc_cs_read_reg(cs, config)) #define GPMC_GET_RAW(reg, st, end, field) \ - get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 0, 0, field) + get_gpmc_timing_reg(cs, (reg), (st), (end), field, GPMC_CD_FCLK, 0, 1, 0) #define GPMC_GET_RAW_BOOL(reg, st, end, field) \ - get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 1, 0, field) + get_gpmc_timing_reg(cs, (reg), (st), (end), field, GPMC_CD_FCLK, 0, 1, 1) #define GPMC_GET_RAW_SHIFT(reg, st, end, shift, field) \ - get_gpmc_timing_reg(cs, (reg), (st), (end), 1, 1, (shift), field) + get_gpmc_timing_reg(cs, (reg), (st), (end), field, GPMC_CD_FCLK, (shift), 1, 1) #define GPMC_GET_TICKS(reg, st, end, field) \ - get_gpmc_timing_reg(cs, (reg), (st), (end), 0, 0, 0, field) + get_gpmc_timing_reg(cs, (reg), (st), (end), field, GPMC_CD_FCLK, 0, 0, 0) +#define GPMC_GET_TICKS_CD(reg, st, end, field, cd) \ + get_gpmc_timing_reg(cs, (reg), (st), (end), field, (cd), 0, 0, 0) static void gpmc_show_regs(int cs, const char *desc) { @@ -476,7 +534,7 @@ static void gpmc_cs_show_timings(int cs, const char *desc) GPMC_GET_TICKS(GPMC_CS_CONFIG6, 0, 3, "bus-turnaround-ns"); GPMC_GET_TICKS(GPMC_CS_CONFIG6, 8, 11, "cycle2cycle-delay-ns"); - GPMC_GET_TICKS(GPMC_CS_CONFIG1, 18, 19, "wait-monitoring-ns"); + GPMC_GET_TICKS_CD(GPMC_CS_CONFIG1, 18, 19, "wait-monitoring-ns", GPMC_CD_CLK); GPMC_GET_TICKS(GPMC_CS_CONFIG1, 25, 26, "clk-activation-ns"); GPMC_GET_TICKS(GPMC_CS_CONFIG6, 16, 19, "wr-data-mux-bus-ns"); @@ -488,8 +546,22 @@ static inline void gpmc_cs_show_timings(int cs, const char *desc) } #endif +/** + * set_gpmc_timing_reg - set a single timing parameter for Chip Select Region. + * Caller is expected to have initialized CONFIG1 GPMCFCLKDIVIDER + * prior to calling this function with @cd equal to GPMC_CD_CLK. + * + * @cs: Chip Select Region. + * @reg: GPMC_CS_CONFIGn register offset. + * @st_bit: Start Bit + * @end_bit: End Bit. Must be >= @st_bit. + * @time: Timing parameter in ns. + * @cd: Timing parameter clock domain. + * @name: Timing parameter name. + * @return: 0 on success, -1 on error. + */ static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, - int time, const char *name) + int time, enum gpmc_clk_domain cd, const char *name) { u32 l; int ticks, mask, nr_bits; @@ -497,12 +569,12 @@ static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, if (time == 0) ticks = 0; else - ticks = gpmc_ns_to_ticks(time); + ticks = gpmc_ns_to_clk_ticks(time, cs, cd); nr_bits = end_bit - st_bit + 1; mask = (1 << nr_bits) - 1; if (ticks > mask) { - pr_err("%s: GPMC error! CS%d: %s: %d ns, %d ticks > %d\n", + pr_err("%s: GPMC CS%d: %s %d ns, %d ticks > %d ticks\n", __func__, cs, name, time, ticks, mask); return -1; @@ -512,7 +584,7 @@ static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, #ifdef DEBUG pr_info( "GPMC CS%d: %-17s: %3d ticks, %3lu ns (was %3i ticks) %3d ns\n", - cs, name, ticks, gpmc_get_fclk_period() * ticks / 1000, + cs, name, ticks, gpmc_get_clk_period(cs, cd) * ticks / 1000, (l >> st_bit) & mask, time); #endif l &= ~(mask << st_bit); @@ -522,11 +594,14 @@ static int set_gpmc_timing_reg(int cs, int reg, int st_bit, int end_bit, return 0; } -#define GPMC_SET_ONE(reg, st, end, field) \ - if (set_gpmc_timing_reg(cs, (reg), (st), (end), \ - t->field, #field) < 0) \ +#define GPMC_SET_ONE_CD(reg, st, end, field, cd) \ + if (set_gpmc_timing_reg(cs, (reg), (st), (end), \ + t->field, (cd), #field) < 0) \ return -1 +#define GPMC_SET_ONE(reg, st, end, field) \ + GPMC_SET_ONE_CD(reg, st, end, field, GPMC_CD_FCLK) + /** * gpmc_calc_waitmonitoring_divider - calculate proper GPMCFCLKDIVIDER based on WAITMONITORINGTIME * WAITMONITORINGTIME will be _at least_ as long as desired, i.e. @@ -644,22 +719,23 @@ int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t, GPMC_SET_ONE(GPMC_CS_CONFIG6, 0, 3, bus_turnaround); GPMC_SET_ONE(GPMC_CS_CONFIG6, 8, 11, cycle2cycle_delay); - GPMC_SET_ONE(GPMC_CS_CONFIG1, 18, 19, wait_monitoring); - GPMC_SET_ONE(GPMC_CS_CONFIG1, 25, 26, clk_activation); - if (gpmc_capability & GPMC_HAS_WR_DATA_MUX_BUS) GPMC_SET_ONE(GPMC_CS_CONFIG6, 16, 19, wr_data_mux_bus); if (gpmc_capability & GPMC_HAS_WR_ACCESS) GPMC_SET_ONE(GPMC_CS_CONFIG6, 24, 28, wr_access); l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG1); + l &= ~0x03; + l |= (div - 1); + gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, l); + + GPMC_SET_ONE_CD(GPMC_CS_CONFIG1, 18, 19, wait_monitoring, GPMC_CD_CLK); + GPMC_SET_ONE(GPMC_CS_CONFIG1, 25, 26, clk_activation); + #ifdef DEBUG pr_info("GPMC CS%d CLK period is %lu ns (div %d)\n", cs, (div * gpmc_get_fclk_period()) / 1000, div); #endif - l &= ~0x03; - l |= (div - 1); - gpmc_cs_write_reg(cs, GPMC_CS_CONFIG1, l); gpmc_cs_bool_timings(cs, &t->bool_timings); gpmc_cs_show_timings(cs, "after gpmc_cs_set_timings"); |