[PATCH 4.10 30/75] memory/atmel-ebi: Fix ns <-> cycles conversions

From: Greg Kroah-Hartman
Date: Mon Mar 13 2017 - 05:01:00 EST


4.10-stable review patch. If anyone has any objections, please let me know.

------------------

From: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>

commit ee194289502a6901cc77dc9a893bf2afd351ac5e upstream.

at91sam9_ebi_get_config() is incorrectly converting timings in clock
cycles into timings in nanoseconds by multiplying the cycle values by
the clk rate instead of the clk period.

at91sam9_ebi_xslate_config() has the same problem for the
tdf_ns -> tdf_cycles conversion.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Reported-by: Chris Leahy <leahycm@xxxxxxxxx>
Fixes: 6a4ec4cd0888 ("memory: add Atmel EBI (External Bus Interface) driver")
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/memory/atmel-ebi.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)

--- a/drivers/memory/atmel-ebi.c
+++ b/drivers/memory/atmel-ebi.c
@@ -93,7 +93,7 @@ static void at91sam9_ebi_get_config(stru
struct at91_ebi_dev_config *conf)
{
struct at91sam9_smc_generic_fields *fields = &ebid->ebi->sam9;
- unsigned int clk_rate = clk_get_rate(ebid->ebi->clk);
+ unsigned int clk_period = NSEC_PER_SEC / clk_get_rate(ebid->ebi->clk);
struct at91sam9_ebi_dev_config *config = &conf->sam9;
struct at91sam9_smc_timings *timings = &config->timings;
unsigned int val;
@@ -102,43 +102,43 @@ static void at91sam9_ebi_get_config(stru
config->mode = val & ~AT91_SMC_TDF;

val = (val & AT91_SMC_TDF) >> 16;
- timings->tdf_ns = clk_rate * val;
+ timings->tdf_ns = clk_period * val;

regmap_fields_read(fields->setup, conf->cs, &val);
timings->ncs_rd_setup_ns = (val >> 24) & 0x1f;
timings->ncs_rd_setup_ns += ((val >> 29) & 0x1) * 128;
- timings->ncs_rd_setup_ns *= clk_rate;
+ timings->ncs_rd_setup_ns *= clk_period;
timings->nrd_setup_ns = (val >> 16) & 0x1f;
timings->nrd_setup_ns += ((val >> 21) & 0x1) * 128;
- timings->nrd_setup_ns *= clk_rate;
+ timings->nrd_setup_ns *= clk_period;
timings->ncs_wr_setup_ns = (val >> 8) & 0x1f;
timings->ncs_wr_setup_ns += ((val >> 13) & 0x1) * 128;
- timings->ncs_wr_setup_ns *= clk_rate;
+ timings->ncs_wr_setup_ns *= clk_period;
timings->nwe_setup_ns = val & 0x1f;
timings->nwe_setup_ns += ((val >> 5) & 0x1) * 128;
- timings->nwe_setup_ns *= clk_rate;
+ timings->nwe_setup_ns *= clk_period;

regmap_fields_read(fields->pulse, conf->cs, &val);
timings->ncs_rd_pulse_ns = (val >> 24) & 0x3f;
timings->ncs_rd_pulse_ns += ((val >> 30) & 0x1) * 256;
- timings->ncs_rd_pulse_ns *= clk_rate;
+ timings->ncs_rd_pulse_ns *= clk_period;
timings->nrd_pulse_ns = (val >> 16) & 0x3f;
timings->nrd_pulse_ns += ((val >> 22) & 0x1) * 256;
- timings->nrd_pulse_ns *= clk_rate;
+ timings->nrd_pulse_ns *= clk_period;
timings->ncs_wr_pulse_ns = (val >> 8) & 0x3f;
timings->ncs_wr_pulse_ns += ((val >> 14) & 0x1) * 256;
- timings->ncs_wr_pulse_ns *= clk_rate;
+ timings->ncs_wr_pulse_ns *= clk_period;
timings->nwe_pulse_ns = val & 0x3f;
timings->nwe_pulse_ns += ((val >> 6) & 0x1) * 256;
- timings->nwe_pulse_ns *= clk_rate;
+ timings->nwe_pulse_ns *= clk_period;

regmap_fields_read(fields->cycle, conf->cs, &val);
timings->nrd_cycle_ns = (val >> 16) & 0x7f;
timings->nrd_cycle_ns += ((val >> 23) & 0x3) * 256;
- timings->nrd_cycle_ns *= clk_rate;
+ timings->nrd_cycle_ns *= clk_period;
timings->nwe_cycle_ns = val & 0x7f;
timings->nwe_cycle_ns += ((val >> 7) & 0x3) * 256;
- timings->nwe_cycle_ns *= clk_rate;
+ timings->nwe_cycle_ns *= clk_period;
}

static int at91_xlate_timing(struct device_node *np, const char *prop,
@@ -334,6 +334,7 @@ static int at91sam9_ebi_apply_config(str
struct at91_ebi_dev_config *conf)
{
unsigned int clk_rate = clk_get_rate(ebid->ebi->clk);
+ unsigned int clk_period = NSEC_PER_SEC / clk_rate;
struct at91sam9_ebi_dev_config *config = &conf->sam9;
struct at91sam9_smc_timings *timings = &config->timings;
struct at91sam9_smc_generic_fields *fields = &ebid->ebi->sam9;
@@ -376,7 +377,7 @@ static int at91sam9_ebi_apply_config(str
val |= AT91SAM9_SMC_NWECYCLE(coded_val);
regmap_fields_write(fields->cycle, conf->cs, val);

- val = DIV_ROUND_UP(timings->tdf_ns, clk_rate);
+ val = DIV_ROUND_UP(timings->tdf_ns, clk_period);
if (val > AT91_SMC_TDF_MAX)
val = AT91_SMC_TDF_MAX;
regmap_fields_write(fields->mode, conf->cs,