[PATCH v2 1/1] drivers: mmc: iproc_sdhci: enable HS200 mode

[Jaehoon Chung]

On 2/26/21 3:15 PM, Rayagonda Kokatanur wrote:
> From: Bharat Gooty <bharat.gooty at broadcom.com>
> 
> Add tuning functionality which is needed for HS200 mode.
> For HS200, program the correct needed 1.8 voltage
> 
> Signed-off-by: Bharat Gooty <bharat.gooty at broadcom.com>
> Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur at broadcom.com>

Reviewed-by: Jaehoon Chung <jh80.chung at samsung.com>

Best Regards,
Jaehoon Chung

> ---
> Changes from v1:
>  --Address review comments from Jaehoon Chung,
>    Add comment for udelay
>    Move #define to top
>    Remove udelay
> 
>  drivers/mmc/iproc_sdhci.c | 92 +++++++++++++++++++++++++++++++++++----
>  1 file changed, 83 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/mmc/iproc_sdhci.c b/drivers/mmc/iproc_sdhci.c
> index 6e4f527e5d..11d86ad658 100644
> --- a/drivers/mmc/iproc_sdhci.c
> +++ b/drivers/mmc/iproc_sdhci.c
> @@ -10,8 +10,11 @@
>  #include <malloc.h>
>  #include <sdhci.h>
>  #include <asm/global_data.h>
> +#include "mmc_private.h"
>  #include <linux/delay.h>
>  
> +#define MAX_TUNING_LOOP	40
> +
>  DECLARE_GLOBAL_DATA_PTR;
>  
>  struct sdhci_iproc_host {
> @@ -140,17 +143,89 @@ static void sdhci_iproc_writeb(struct sdhci_host *host, u8 val, int reg)
>  
>  static int sdhci_iproc_set_ios_post(struct sdhci_host *host)
>  {
> -	u32 ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> +	struct mmc *mmc = (struct mmc *)host->mmc;
> +	u32 ctrl;
> +
> +	if (mmc->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
> +		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> +		ctrl |= SDHCI_CTRL_VDD_180;
> +		sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
> +	}
>  
> -	/* Reset UHS mode bits */
> -	ctrl &= ~SDHCI_CTRL_UHS_MASK;
> +	sdhci_set_uhs_timing(host);
> +	return 0;
> +}
>  
> -	if (host->mmc->ddr_mode)
> -		ctrl |= UHS_DDR50_BUS_SPEED;
> +static void sdhci_start_tuning(struct sdhci_host *host)
> +{
> +	u32 ctrl;
>  
> +	ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> +	ctrl |= SDHCI_CTRL_EXEC_TUNING;
>  	sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
>  
> -	return 0;
> +	sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_INT_ENABLE);
> +	sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_SIGNAL_ENABLE);
> +}
> +
> +static void sdhci_end_tuning(struct sdhci_host *host)
> +{
> +	/* Enable only interrupts served by the SD controller */
> +	sdhci_writel(host, SDHCI_INT_DATA_MASK | SDHCI_INT_CMD_MASK,
> +		     SDHCI_INT_ENABLE);
> +	/* Mask all sdhci interrupt sources */
> +	sdhci_writel(host, 0x0, SDHCI_SIGNAL_ENABLE);
> +}
> +
> +static int sdhci_iproc_execute_tuning(struct mmc *mmc, u8 opcode)
> +{
> +	struct mmc_cmd cmd;
> +	u32 ctrl;
> +	u32 blocksize = SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG, 64);
> +	struct sdhci_host *host = dev_get_priv(mmc->dev);
> +	char tuning_loop_counter = MAX_TUNING_LOOP;
> +	int ret = 0;
> +
> +	sdhci_start_tuning(host);
> +
> +	cmd.cmdidx = opcode;
> +	cmd.resp_type = MMC_RSP_R1;
> +	cmd.cmdarg = 0;
> +
> +	if (opcode == MMC_CMD_SEND_TUNING_BLOCK_HS200 && mmc->bus_width == 8)
> +		blocksize = SDHCI_MAKE_BLKSZ(SDHCI_DEFAULT_BOUNDARY_ARG, 128);
> +
> +	sdhci_writew(host, blocksize, SDHCI_BLOCK_SIZE);
> +	sdhci_writew(host, 1, SDHCI_BLOCK_COUNT);
> +	sdhci_writew(host, SDHCI_TRNS_READ, SDHCI_TRANSFER_MODE);
> +
> +	do {
> +		mmc_send_cmd(mmc, &cmd, NULL);
> +		if (opcode == MMC_CMD_SEND_TUNING_BLOCK)
> +			/*
> +			 * For tuning command, do not do busy loop. As tuning
> +			 * is happening (CLK-DATA latching for setup/hold time
> +			 * requirements), give time to complete
> +			 */
> +			udelay(1);
> +
> +		ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> +
> +		if (tuning_loop_counter-- == 0)
> +			break;
> +
> +	} while (ctrl & SDHCI_CTRL_EXEC_TUNING);
> +
> +	if (tuning_loop_counter < 0 || (!(ctrl & SDHCI_CTRL_TUNED_CLK))) {
> +		ctrl &= ~(SDHCI_CTRL_TUNED_CLK | SDHCI_CTRL_EXEC_TUNING);
> +		sdhci_writel(host, ctrl, SDHCI_HOST_CONTROL2);
> +		printf("%s:Tuning failed, opcode = 0x%02x\n", __func__, opcode);
> +		ret = -EIO;
> +	}
> +
> +	sdhci_end_tuning(host);
> +
> +	return ret;
>  }
>  
>  static struct sdhci_ops sdhci_platform_ops = {
> @@ -163,6 +238,7 @@ static struct sdhci_ops sdhci_platform_ops = {
>  	.write_b = sdhci_iproc_writeb,
>  #endif
>  	.set_ios_post = sdhci_iproc_set_ios_post,
> +	.platform_execute_tuning = sdhci_iproc_execute_tuning,
>  };
>  
>  struct iproc_sdhci_plat {
> @@ -190,9 +266,7 @@ static int iproc_sdhci_probe(struct udevice *dev)
>  
>  	host->name = dev->name;
>  	host->ioaddr = dev_read_addr_ptr(dev);
> -	host->voltages = MMC_VDD_165_195 |
> -			 MMC_VDD_32_33 | MMC_VDD_33_34;
> -	host->quirks = SDHCI_QUIRK_BROKEN_VOLTAGE | SDHCI_QUIRK_BROKEN_R1B;
> +	host->quirks = SDHCI_QUIRK_BROKEN_R1B;
>  	host->host_caps = MMC_MODE_DDR_52MHz;
>  	host->index = fdtdec_get_uint(gd->fdt_blob, node, "index", 0);
>  	host->ops = &sdhci_platform_ops;
>