From: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
To: Adrian Hunter <adrian.hunter@intel.com>,
Kevin Liu <kliu5@marvell.com>,
Michal Simek <michal.simek@xilinx.com>,
Suneel Garapati <suneel.garapati@xilinx.com>,
Ulf Hansson <ulf.hansson@linaro.org>
Cc: linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org
Subject: [PATCH 6/7] mmc: sdhci: squash v2/v3+ clock calculation differences
Date: Thu, 02 Apr 2020 13:54:57 +0200 [thread overview]
Message-ID: <ea92e0e23c8cc79b960d9129aa64d0371e630b7f.1585827904.git.mirq-linux@rere.qmqm.pl> (raw)
In-Reply-To: <cover.1585827904.git.mirq-linux@rere.qmqm.pl>
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(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index d750c0997c3f..01fd897f8f3c 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -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;
--
2.20.1
next prev parent reply other threads:[~2020-04-02 11:55 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-02 11:54 [PATCH 0/7] SDHCI clock handling fixes and cleanups Michał Mirosław
2020-04-02 11:54 ` [PATCH 3/7] mmc: sdhci: fix SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN Michał Mirosław
2020-04-15 13:06 ` Adrian Hunter
2020-04-15 16:03 ` Michał Mirosław
2020-04-16 7:40 ` Adrian Hunter
2020-04-02 11:54 ` [PATCH 2/7] mmc: sdhci: fix programmable clock config from preset value Michał Mirosław
2020-04-15 12:44 ` Adrian Hunter
2020-04-02 11:54 ` [PATCH 1/7] mmc: sdhci: fix base clock usage in " Michał Mirosław
2020-04-15 12:25 ` Adrian Hunter
2020-04-15 16:28 ` Michał Mirosław
2020-04-16 8:26 ` Adrian Hunter
2020-04-17 13:55 ` Alan Cooper
2020-04-20 5:31 ` Adrian Hunter
2020-04-02 11:54 ` [PATCH 4/7] mmc: sdhci: move SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN frequency limit Michał Mirosław
2020-04-15 13:16 ` Adrian Hunter
2020-04-15 16:16 ` Michał Mirosław
2020-04-16 7:43 ` Adrian Hunter
2020-04-02 11:54 ` Michał Mirosław [this message]
2020-04-02 11:54 ` [PATCH 5/7] mmc: sdhci: simplify clock frequency calculation Michał Mirosław
2020-04-03 13:02 ` kbuild test robot
2020-04-03 16:15 ` Michał Mirosław
2020-04-15 13:54 ` Adrian Hunter
2020-04-15 16:45 ` Michał Mirosław
2020-04-02 11:54 ` [PATCH 7/7] mmc: sdhci: respect non-zero div quirk in programmable clock mode Michał Mirosław
2020-04-03 16:03 ` kbuild test robot
2020-04-15 8:52 ` [PATCH 0/7] SDHCI clock handling fixes and cleanups Ulf Hansson
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