This patch focuses on clock setting for RK3288 mmc controller.
In RK3288 mmc controller, CLKDIV register can only be set 0 or 1,
and if DDR 8bit mode, CLKDIV register must be set 1.
Reported-by Doug Anderson <diand...@chromium.org>
Suggested-by: Jaehoon Chung <jh80.ch...@samsung.com>
Suggested-by: Doug Anderson <diand...@chromium.org>
Signed-off-by: Addy Ke <addy...@rock-chips.com>
---
changes since v1:
- dw_mci_rk3288_setup_clock: do not call clk_get_rate(), just use the
host->bus_hz which is already called by dw_mmc.c, suggested by Jaehoon Chung
changes since v2:
- merge from ChromiumOS tree, fix up clock settting bug,
which cause DDR50 mode for emmc not to work, reported by Doug Anderson
- remove MMC_TIMING_UHS_DDR50 condition, because on RK3288 only emmc can work
in 8bit mode, suggested by Doug Anderson
.../devicetree/bindings/mmc/rockchip-dw-mshc.txt | 6 ++-
drivers/mmc/host/dw_mmc-pltfm.c | 56 +++++++++++++++++++++-
2 files changed, 58 insertions(+), 4 deletions(-)
diff --git a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
index c559f3f..c327c2d 100644
--- a/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
+++ b/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
@@ -10,12 +10,14 @@ extensions to the Synopsys Designware Mobile Storage Host
Controller.
Required Properties:
* compatible: should be
- - "rockchip,rk2928-dw-mshc": for Rockchip RK2928 and following
+ - "rockchip,rk2928-dw-mshc": for Rockchip RK2928 and following,
+ before RK3288
+ - "rockchip,rk3288-dw-mshc": for Rockchip RK3288
Example:
rkdwmmc0@12200000 {
- compatible = "rockchip,rk2928-dw-mshc";
+ compatible = "rockchip,rk3288-dw-mshc";
reg = <0x12200000 0x1000>;
interrupts = <0 75 0>;
#address-cells = <1>;
diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
index d4a47a9..b547f7a 100644
--- a/drivers/mmc/host/dw_mmc-pltfm.c
+++ b/drivers/mmc/host/dw_mmc-pltfm.c
@@ -21,17 +21,67 @@
#include <linux/mmc/mmc.h>
#include <linux/mmc/dw_mmc.h>
#include <linux/of.h>
+#include <linux/clk.h>
#include "dw_mmc.h"
#include "dw_mmc-pltfm.h"
+#define RK3288_CLKGEN_DIV 2
+
static void dw_mci_pltfm_prepare_command(struct dw_mci *host, u32 *cmdr)
{
*cmdr |= SDMMC_CMD_USE_HOLD_REG;
}
-static const struct dw_mci_drv_data rockchip_drv_data = {
+static int dw_mci_rk3288_setup_clock(struct dw_mci *host)
+{
+ host->bus_hz /= RK3288_CLKGEN_DIV;
+
+ return 0;
+}
+
+static void dw_mci_rk3288_set_ios(struct dw_mci *host, struct mmc_ios *ios)
+{
+ int ret;
+ unsigned int cclkin;
+ u32 bus_hz;
+
+ /*
+ * cclkin: source clock of mmc controller.
+ * bus_hz: card interface clock generated by CLKGEN.
+ * bus_hz = cclkin / RK3288_CLKGEN_DIV;
+ * ios->clock = (div == 0) ? bus_hz : (bus_hz / (2 * div))
+ *
+ * Note: div can only be 0 or 1
+ * if DDR50 8bit mode(only emmc work in 8bit mode),
+ * div must be set 1
+ */
+ if ((ios->bus_width == MMC_BUS_WIDTH_8) &&
+ (ios->timing == MMC_TIMING_MMC_DDR52))
+ cclkin = 2 * ios->clock * RK3288_CLKGEN_DIV;
+ else
+ cclkin = ios->clock * RK3288_CLKGEN_DIV;
+
+ ret = clk_set_rate(host->ciu_clk, cclkin);
+ if (ret)
+ dev_warn(host->dev, "failed to set rate %uHz\n", ios->clock);
+
+ bus_hz = clk_get_rate(host->ciu_clk) / RK3288_CLKGEN_DIV;
+ if (bus_hz != host->bus_hz) {
+ host->bus_hz = bus_hz;
+ /* force dw_mci_setup_bus() */
+ host->current_speed = 0;
+ }
+}
+
+static const struct dw_mci_drv_data rk2928_drv_data = {
+ .prepare_command = dw_mci_pltfm_prepare_command,
+};
+
+static const struct dw_mci_drv_data rk3288_drv_data = {
.prepare_command = dw_mci_pltfm_prepare_command,
+ .set_ios = dw_mci_rk3288_set_ios,
+ .setup_clock = dw_mci_rk3288_setup_clock,
};
static const struct dw_mci_drv_data socfpga_drv_data = {
@@ -95,7 +145,9 @@ EXPORT_SYMBOL_GPL(dw_mci_pltfm_pmops);
static const struct of_device_id dw_mci_pltfm_match[] = {
{ .compatible = "snps,dw-mshc", },
{ .compatible = "rockchip,rk2928-dw-mshc",
- .data = &rockchip_drv_data },
+ .data = &rk2928_drv_data },
+ { .compatible = "rockchip,rk3288-dw-mshc",
+ .data = &rk3288_drv_data },
{ .compatible = "altr,socfpga-dw-mshc",
.data = &socfpga_drv_data },
{},
--
1.8.3.2
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