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authorPeter Geis <pgwipeout@gmail.com>2022-03-05 16:58:35 -0500
committerUlf Hansson <ulf.hansson@linaro.org>2022-03-07 12:56:48 +0100
commit52c92286b71e28d88642a4a416f40fbdb6cbb46f (patch)
tree906e7a07330f594bfcbf3b7c3f646aac2ab55da5 /drivers/mmc
parentc4313e75001492f8a288d3ffd595544cbc880821 (diff)
mmc: dw-mmc-rockchip: Fix handling invalid clock rates
The Rockchip rk356x ciu clock cannot be set as low as the dw-mmc hardware supports. This leads to a situation during card initialization where the clock is set lower than the clock driver can support. The dw-mmc-rockchip driver spews errors when this happens. For normal operation this only happens a few times during boot, but when cd-broken is enabled (in cases such as the SoQuartz module) this fires multiple times each poll cycle. Fix this by testing the lowest possible frequency that the clock driver can support which is within the mmc specification. Divide that rate by the internal divider and set f_min to this. Signed-off-by: Peter Geis <pgwipeout@gmail.com> Link: https://lore.kernel.org/r/20220305215835.2210388-3-pgwipeout@gmail.com Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/dw_mmc-rockchip.c27
1 files changed, 23 insertions, 4 deletions
diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c
index 95d0ec0f5f3a..f825487aa739 100644
--- a/drivers/mmc/host/dw_mmc-rockchip.c
+++ b/drivers/mmc/host/dw_mmc-rockchip.c
@@ -15,7 +15,9 @@
#include "dw_mmc.h"
#include "dw_mmc-pltfm.h"
-#define RK3288_CLKGEN_DIV 2
+#define RK3288_CLKGEN_DIV 2
+
+static const unsigned int freqs[] = { 100000, 200000, 300000, 400000 };
struct dw_mci_rockchip_priv_data {
struct clk *drv_clk;
@@ -51,7 +53,7 @@ static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
ret = clk_set_rate(host->ciu_clk, cclkin);
if (ret)
- dev_warn(host->dev, "failed to set rate %uHz\n", ios->clock);
+ dev_warn(host->dev, "failed to set rate %uHz err: %d\n", cclkin, ret);
bus_hz = clk_get_rate(host->ciu_clk) / RK3288_CLKGEN_DIV;
if (bus_hz != host->bus_hz) {
@@ -290,13 +292,30 @@ static int dw_mci_rk3288_parse_dt(struct dw_mci *host)
static int dw_mci_rockchip_init(struct dw_mci *host)
{
+ int ret, i;
+
/* It is slot 8 on Rockchip SoCs */
host->sdio_id0 = 8;
- if (of_device_is_compatible(host->dev->of_node,
- "rockchip,rk3288-dw-mshc"))
+ if (of_device_is_compatible(host->dev->of_node, "rockchip,rk3288-dw-mshc")) {
host->bus_hz /= RK3288_CLKGEN_DIV;
+ /* clock driver will fail if the clock is less than the lowest source clock
+ * divided by the internal clock divider. Test for the lowest available
+ * clock and set the minimum freq to clock / clock divider.
+ */
+
+ for (i = 0; i < ARRAY_SIZE(freqs); i++) {
+ ret = clk_round_rate(host->ciu_clk, freqs[i] * RK3288_CLKGEN_DIV);
+ if (ret > 0) {
+ host->minimum_speed = ret / RK3288_CLKGEN_DIV;
+ break;
+ }
+ }
+ if (ret < 0)
+ dev_warn(host->dev, "no valid minimum freq: %d\n", ret);
+ }
+
return 0;
}