@@ -1756,82 +1756,74 @@ static u16 sdhci_get_preset_value(struct sdhci_host *host)
u16 sdhci_calc_clk(struct sdhci_host *host, unsigned int clock,
unsigned int *actual_clock)
{
- unsigned int div = 0; /* Initialized for compiler warning */
- int real_div = div, clk_mul = 1;
+ unsigned int div, real_div, clk_mul = 1;
u16 clk = 0;
- bool use_base_clk;
if (clock == 0)
unreachable();
- if (host->version >= SDHCI_SPEC_300) {
- if (host->preset_enabled) {
- u16 pre_val;
-
- pre_val = sdhci_get_preset_value(host);
- div = FIELD_GET(SDHCI_PRESET_SDCLK_FREQ_MASK, pre_val);
- if (pre_val & SDHCI_PRESET_CLKGEN_SEL) {
- clk = SDHCI_PROG_CLOCK_MODE;
- real_div = div + 1;
- clk_mul = host->clk_mul ?: 1;
- } else {
- real_div = max_t(int, 1, div << 1);
- }
+ if (host->preset_enabled) {
+ /* Only version 3.00+ can have preset_enabled */
+ u16 pre_val;
+
+ pre_val = sdhci_get_preset_value(host);
+ div = FIELD_GET(SDHCI_PRESET_SDCLK_FREQ_MASK, pre_val);
+ if (pre_val & SDHCI_PRESET_CLKGEN_SEL) {
+ clk = SDHCI_PROG_CLOCK_MODE;
+ real_div = div + 1;
+ clk_mul = host->clk_mul ?: 1;
+ } else {
+ real_div = max_t(int, 1, div << 1);
+ }
+
+ goto clock_set;
+ }
+
+ /*
+ * Check if the Host Controller supports Programmable Clock
+ * Mode.
+ */
+ if (host->version >= SDHCI_SPEC_300 && host->clk_mul) {
+ div = DIV_ROUND_UP(host->max_clk * host->clk_mul, clock);
+
+ if (div <= SDHCI_MAX_DIV_SPEC_300 / 2 + 1) {
+ /*
+ * Set Programmable Clock Mode in the Clock
+ * Control register.
+ */
+ clk = SDHCI_PROG_CLOCK_MODE;
+ real_div = div;
+ clk_mul = host->clk_mul;
+ div--;
+
goto clock_set;
}
/*
- * Check if the Host Controller supports Programmable Clock
- * Mode.
+ * Divisor is too big for requested clock rate.
+ * Fall back to the base clock, then.
*/
- use_base_clk = !host->clk_mul;
+ }
- if (!use_base_clk) {
- div = DIV_ROUND_UP(host->max_clk * host->clk_mul, clock);
+ div = DIV_ROUND_UP(host->max_clk, clock);
- if (div <= SDHCI_MAX_DIV_SPEC_300 / 2 + 1) {
- /*
- * Set Programmable Clock Mode in the Clock
- * Control register.
- */
- clk = SDHCI_PROG_CLOCK_MODE;
- real_div = div;
- clk_mul = host->clk_mul;
- div--;
- } else {
- /*
- * Divisor is too big for requested clock rate.
- * Use the base clock, then.
- */
- use_base_clk = true;
- }
- }
+ if (div == 1 && (host->quirks2 & SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN))
+ div = 2;
- if (use_base_clk) {
- /* Version 3.00 divisors must be 1 or a multiple of 2. */
- div = DIV_ROUND_UP(host->max_clk, clock);
- if (div > 1) {
- div = min(div, SDHCI_MAX_DIV_SPEC_300);
- div = round_up(div, 2);
- }
- div >>= 1;
- if (host->quirks2 & SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN)
- div += !div;
-
- real_div = div * 2 + !div;
- }
+ if (host->version >= SDHCI_SPEC_300) {
+ /* Version 3.00 divisors must be a multiple of 2. */
+ div = min(div, SDHCI_MAX_DIV_SPEC_300);
+ div = DIV_ROUND_UP(div, 2);
} else {
/* Version 2.00 divisors must be a power of 2. */
- div = DIV_ROUND_UP(host->max_clk, clock);
div = min(div, SDHCI_MAX_DIV_SPEC_200);
- div = roundup_pow_of_two(div);
- real_div = div;
- div >>= 1;
+ div = roundup_pow_of_two(div) / 2;
}
+ real_div = div * 2 + !div;
+
clock_set:
- if (real_div)
- *actual_clock = (host->max_clk * clk_mul) / real_div;
+ *actual_clock = (host->max_clk * clk_mul) / real_div;
clk |= (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIV_MASK_LEN)
<< SDHCI_DIVIDER_HI_SHIFT;
SDHCI V2 differs from base-clock-V3+ only in allowed divisor values. Remove the duplicate version of code. We can see now, that 'real_div' can't be zero. Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> --- drivers/mmc/host/sdhci.c | 106 ++++++++++++++++++--------------------- 1 file changed, 49 insertions(+), 57 deletions(-)