mmc: sunxi: Support new mode
Almost all of the newer Allwinner SoCs have a new operating mode for the
eMMC clocks that needs to be enabled in both the clock and the MMC
controller.
Details about that mode are sparse, and the name itself (new mode vs old
mode) doesn't give much details, but it seems that the it changes the
sampling of the MMC clock. One side effect is also that it divides the
parent clock rate by 2.
Add support for it through a Kconfig option.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
diff --git a/drivers/mmc/sunxi_mmc.c b/drivers/mmc/sunxi_mmc.c
index 588574f..bc638ae 100644
--- a/drivers/mmc/sunxi_mmc.c
+++ b/drivers/mmc/sunxi_mmc.c
@@ -96,6 +96,18 @@
static int mmc_set_mod_clk(struct sunxi_mmc_priv *priv, unsigned int hz)
{
unsigned int pll, pll_hz, div, n, oclk_dly, sclk_dly;
+ bool new_mode = false;
+ u32 val = 0;
+
+ if (IS_ENABLED(CONFIG_MMC_SUNXI_HAS_NEW_MODE) && (priv->mmc_no == 2))
+ new_mode = true;
+
+ /*
+ * The MMC clock has an extra /2 post-divider when operating in the new
+ * mode.
+ */
+ if (new_mode)
+ hz = hz * 2;
if (hz <= 24000000) {
pll = CCM_MMC_CTRL_OSCM24;
@@ -152,9 +164,18 @@
#endif
}
- writel(CCM_MMC_CTRL_ENABLE | pll | CCM_MMC_CTRL_SCLK_DLY(sclk_dly) |
- CCM_MMC_CTRL_N(n) | CCM_MMC_CTRL_OCLK_DLY(oclk_dly) |
- CCM_MMC_CTRL_M(div), priv->mclkreg);
+ if (new_mode) {
+#ifdef CONFIG_MMC_SUNXI_HAS_NEW_MODE
+ val = CCM_MMC_CTRL_MODE_SEL_NEW;
+ writel(SUNXI_MMC_NTSR_MODE_SEL_NEW, &priv->reg->ntsr);
+#endif
+ } else {
+ val = CCM_MMC_CTRL_OCLK_DLY(oclk_dly) |
+ CCM_MMC_CTRL_SCLK_DLY(sclk_dly);
+ }
+
+ writel(CCM_MMC_CTRL_ENABLE| pll | CCM_MMC_CTRL_N(n) |
+ CCM_MMC_CTRL_M(div) | val, priv->mclkreg);
debug("mmc %u set mod-clk req %u parent %u n %u m %u rate %u\n",
priv->mmc_no, hz, pll_hz, 1u << n, div, pll_hz / (1u << n) / div);