Re: [PATCH] mmc: dw_mmc: add support for RK3288

[Jaehoon Chung <jh80.chung@samsung.com>]

Acked-by: Jaehoon Chung <jh80.chung@samsung.com>

Best Regards,
Jaehoon Chung

On 07/31/2014 03:01 PM, Addy Ke wrote:
> 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 <dianders@chromium.org>
> Suggested-by: Jaehoon Chung <jh80.chung@samsung.com>
> Suggested-by: Doug Anderson <dianders@chromium.org>
> Signed-off-by: Addy Ke <addy.ke@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 },
>  	{},
>