Re: [PATCH v2 07/11] mmc: host: omap_hsmmc: add tuning support

From: Ulf Hansson
Date: Tue Aug 25 2015 - 10:12:14 EST

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In reply to: Kishon Vijay Abraham I: "[PATCH v2 07/11] mmc: host: omap_hsmmc: add tuning support"
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On 25 August 2015 at 11:05, Kishon Vijay Abraham I <kishon@xxxxxx> wrote:
> From: Balaji T K <balajitk@xxxxxx>
>
> MMC tuning procedure is required to support SD card
> UHS1-SDR104 mode and EMMC HS200 mode.
>
> The tuning function omap_execute_tuning() will only
> be called by the MMC/SD core if the corresponding
> speed modes are supported by the OMAP silicon which
> is set in the mmc host "caps" field.
>
> Signed-off-by: Balaji T K <balajitk@xxxxxx>
> Signed-off-by: Viswanath Puttagunta <vishp@xxxxxx>
> Signed-off-by: Sourav Poddar <sourav.poddar@xxxxxx>
> [kishon@xxxxxx : cleanup the tuning sequence]
> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> ---
> drivers/mmc/host/omap_hsmmc.c | 234 ++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 232 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index c042b91..43485c3 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -18,6 +18,7 @@
> #include <linux/module.h>
> #include <linux/init.h>
> #include <linux/kernel.h>
> +#include <linux/slab.h>
> #include <linux/debugfs.h>
> #include <linux/dmaengine.h>
> #include <linux/seq_file.h>
> @@ -49,6 +50,7 @@
> /* OMAP HSMMC Host Controller Registers */
> #define OMAP_HSMMC_SYSSTATUS 0x0014
> #define OMAP_HSMMC_CON 0x002C
> +#define OMAP_HSMMC_DLL 0x0034
> #define OMAP_HSMMC_SDMASA 0x0100
> #define OMAP_HSMMC_BLK 0x0104
> #define OMAP_HSMMC_ARG 0x0108
> @@ -66,6 +68,7 @@
> #define OMAP_HSMMC_ISE 0x0138
> #define OMAP_HSMMC_AC12 0x013C
> #define OMAP_HSMMC_CAPA 0x0140
> +#define OMAP_HSMMC_CAPA2 0x0144
>
> #define VS18 (1 << 26)
> #define VS30 (1 << 25)
> @@ -114,6 +117,7 @@
>
> /* AC12 */
> #define AC12_V1V8_SIGEN (1 << 19)
> +#define AC12_SCLK_SEL (1 << 23)
> #define AC12_UHSMC_MASK (7 << 16)
> #define AC12_UHSMC_SDR12 (0 << 16)
> #define AC12_UHSMC_SDR25 (1 << 16)
> @@ -122,6 +126,18 @@
> #define AC12_UHSMC_DDR50 (4 << 16)
> #define AC12_UHSMC_RES (0x7 << 16)
>
> +/* DLL */
> +#define DLL_SWT (1 << 20)
> +#define DLL_FORCE_SR_C_SHIFT 13
> +#define DLL_FORCE_SR_C_MASK 0x7f
> +#define DLL_FORCE_VALUE (1 << 12)
> +#define DLL_CALIB (1 << 1)
> +
> +#define MAX_PHASE_DELAY 0x7c
> +
> +/* CAPA2 */
> +#define CAPA2_TSDR50 (1 << 13)
> +
> /* Interrupt masks for IE and ISE register */
> #define CC_EN (1 << 0)
> #define TC_EN (1 << 1)
> @@ -202,6 +218,7 @@ struct omap_hsmmc_host {
> int vqmmc_enabled;
> resource_size_t mapbase;
> spinlock_t irq_lock; /* Prevent races with irq handler */
> + struct completion buf_ready;
> unsigned int dma_len;
> unsigned int dma_sg_idx;
> unsigned char bus_mode;
> @@ -229,6 +246,9 @@ struct omap_hsmmc_host {
> struct omap_hsmmc_next next_data;
> struct omap_hsmmc_platform_data *pdata;
>
> + u32 *tuning_data;
> + int tuning_size;
> +
> /* return MMC cover switch state, can be NULL if not supported.
> *
> * possible return values:
> @@ -245,8 +265,39 @@ struct omap_mmc_of_data {
> u8 controller_flags;
> };
>
> +static const u8 ref_tuning_4bits[] = {
> + 0xff, 0x0f, 0xff, 0x00, 0xff, 0xcc, 0xc3, 0xcc,
> + 0xc3, 0x3c, 0xcc, 0xff, 0xfe, 0xff, 0xfe, 0xef,
> + 0xff, 0xdf, 0xff, 0xdd, 0xff, 0xfb, 0xff, 0xfb,
> + 0xbf, 0xff, 0x7f, 0xff, 0x77, 0xf7, 0xbd, 0xef,
> + 0xff, 0xf0, 0xff, 0xf0, 0x0f, 0xfc, 0xcc, 0x3c,
> + 0xcc, 0x33, 0xcc, 0xcf, 0xff, 0xef, 0xff, 0xee,
> + 0xff, 0xfd, 0xff, 0xfd, 0xdf, 0xff, 0xbf, 0xff,
> + 0xbb, 0xff, 0xf7, 0xff, 0xf7, 0x7f, 0x7b, 0xde,
> +};
> +
> +static const u8 ref_tuning_8bits[] = {
> + 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00, 0x00,
> + 0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc, 0xcc,
> + 0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff, 0xff,
> + 0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee, 0xff,
> + 0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd, 0xdd,
> + 0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff, 0xbb,
> + 0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff, 0xff,
> + 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee, 0xff,
> + 0xff, 0xff, 0xff, 0x00, 0xff, 0xff, 0xff, 0x00,
> + 0x00, 0xff, 0xff, 0xcc, 0xcc, 0xcc, 0x33, 0xcc,
> + 0xcc, 0xcc, 0x33, 0x33, 0xcc, 0xcc, 0xcc, 0xff,
> + 0xff, 0xff, 0xee, 0xff, 0xff, 0xff, 0xee, 0xee,
> + 0xff, 0xff, 0xff, 0xdd, 0xff, 0xff, 0xff, 0xdd,
> + 0xdd, 0xff, 0xff, 0xff, 0xbb, 0xff, 0xff, 0xff,
> + 0xbb, 0xbb, 0xff, 0xff, 0xff, 0x77, 0xff, 0xff,
> + 0xff, 0x77, 0x77, 0xff, 0x77, 0xbb, 0xdd, 0xee,
> +};

These bit patterns already exists in the mmc core as a part of the
mmc_send_tuning() API.

> +
> static void omap_hsmmc_start_dma_transfer(struct omap_hsmmc_host *host);
> static void omap_hsmmc_conf_bus_power(struct omap_hsmmc_host *host, int iov);
> +static void omap_hsmmc_disable_tuning(struct omap_hsmmc_host *host);
>
> static int omap_hsmmc_card_detect(struct device *dev)
> {
> @@ -609,8 +660,12 @@ static void omap_hsmmc_enable_irq(struct omap_hsmmc_host *host,
> {
> u32 irq_mask = INT_EN_MASK;
> unsigned long flags;
> + bool is_tuning;
>
> - if (host->use_dma)
> + is_tuning = (cmd->opcode == MMC_SEND_TUNING_BLOCK) ||
> + (cmd->opcode == MMC_SEND_TUNING_BLOCK_HS200);
> +
> + if (!is_tuning && host->use_dma)
> irq_mask &= ~(BRR_EN | BWR_EN);
>
> /* Disable timeout for erases */
> @@ -956,7 +1011,11 @@ omap_hsmmc_start_command(struct omap_hsmmc_host *host, struct mmc_command *cmd,
> cmdreg &= ~(DDIR);
> }
>
> - if (host->use_dma)
> + /* Tuning command is special. Data Present Select should be set */
> + if ((cmd->opcode == MMC_SEND_TUNING_BLOCK) ||
> + (cmd->opcode == MMC_SEND_TUNING_BLOCK_HS200))
> + cmdreg |= DP_SELECT | DDIR;
> + else if (host->use_dma)
> cmdreg |= DMAE;
>
> host->req_in_progress = 1;
> @@ -1187,6 +1246,7 @@ static void omap_hsmmc_do_irq(struct omap_hsmmc_host *host, int status)
> struct mmc_data *data;
> int end_cmd = 0, end_trans = 0;
> int error = 0;
> + int i;
>
> data = host->data;
> dev_vdbg(mmc_dev(host->mmc), "IRQ Status is %x\n", status);
> @@ -1222,6 +1282,13 @@ static void omap_hsmmc_do_irq(struct omap_hsmmc_host *host, int status)
> }
> }
>
> + if (status & BRR_EN) {
> + for (i = 0; i < host->tuning_size / 4; i++)
> + host->tuning_data[i] =
> + OMAP_HSMMC_READ(host->base, DATA);
> + complete(&host->buf_ready);
> + }
> +
> OMAP_HSMMC_WRITE(host->base, STAT, status);
> if (end_cmd || ((status & CC_EN) && host->cmd))
> omap_hsmmc_cmd_done(host, host->cmd);
> @@ -1721,6 +1788,7 @@ static void omap_hsmmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> if (ios->power_mode != host->power_mode) {
> switch (ios->power_mode) {
> case MMC_POWER_OFF:
> + omap_hsmmc_disable_tuning(host);
> mmc_pdata(host)->set_power(host->dev, 0, 0);
> break;
> case MMC_POWER_UP:
> @@ -2035,6 +2103,166 @@ static int omap_hsmmc_card_busy(struct mmc_host *mmc)
> return ret;
> }
>
> +static inline void omap_hsmmc_set_dll(struct omap_hsmmc_host *host, int count)
> +{
> + int i;
> + u32 dll;
> +
> + dll = OMAP_HSMMC_READ(host->base, DLL);
> + dll |= DLL_FORCE_VALUE;
> + dll &= ~(DLL_FORCE_SR_C_MASK << DLL_FORCE_SR_C_SHIFT);
> + dll |= (count << DLL_FORCE_SR_C_SHIFT);
> + OMAP_HSMMC_WRITE(host->base, DLL, dll);
> +
> + dll |= DLL_CALIB;
> + OMAP_HSMMC_WRITE(host->base, DLL, dll);
> + for (i = 0; i < 1000; i++) {
> + if (OMAP_HSMMC_READ(host->base, DLL) & DLL_CALIB)
> + break;
> + }
> + dll &= ~DLL_CALIB;
> + OMAP_HSMMC_WRITE(host->base, DLL, dll);
> +}
> +
> +static void omap_hsmmc_disable_tuning(struct omap_hsmmc_host *host)
> +{
> + int val;
> +
> + val = OMAP_HSMMC_READ(host->base, AC12);
> + val &= ~(AC12_SCLK_SEL);
> + OMAP_HSMMC_WRITE(host->base, AC12, val);
> +
> + val = OMAP_HSMMC_READ(host->base, DLL);
> + val &= ~(DLL_FORCE_VALUE | DLL_SWT);
> + OMAP_HSMMC_WRITE(host->base, DLL, val);
> +}
> +
> +static int omap_hsmmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
> +{
> + u32 val;
> + u8 cur_match, prev_match = 0;
> + int ret;
> + u32 phase_delay = 0;
> + u32 start_window = 0, max_window = 0;
> + u32 length = 0, max_len = 0;
> + const u8 *tuning_ref;
> + struct mmc_ios *ios = &mmc->ios;
> + struct omap_hsmmc_host *host;
> + struct mmc_command cmd = {0};
> + struct mmc_request mrq = {NULL};
> +
> + /* clock tuning is not needed for upto 52MHz */
> + if (ios->clock <= OMAP_MMC_MAX_CLOCK)
> + return 0;
> +
> + host = mmc_priv(mmc);
> +
> + val = OMAP_HSMMC_READ(host->base, CAPA2);
> + if (ios->timing == MMC_TIMING_UHS_SDR50 && !(val & CAPA2_TSDR50))
> + return 0;
> +
> + switch (ios->bus_width) {
> + case MMC_BUS_WIDTH_8:
> + tuning_ref = ref_tuning_8bits;
> + host->tuning_size = sizeof(ref_tuning_8bits);
> + break;
> + case MMC_BUS_WIDTH_4:
> + tuning_ref = ref_tuning_4bits;
> + host->tuning_size = sizeof(ref_tuning_4bits);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + host->tuning_data = kzalloc(host->tuning_size, GFP_KERNEL);
> + if (!host->tuning_data)
> + return -ENOMEM;
> +
> + val = OMAP_HSMMC_READ(host->base, DLL);
> + val |= DLL_SWT;
> + OMAP_HSMMC_WRITE(host->base, DLL, val);
> +
> + while (phase_delay <= MAX_PHASE_DELAY) {
> + omap_hsmmc_set_dll(host, phase_delay);
> +
> + cmd.opcode = opcode;
> + cmd.arg = 0;
> + cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
> + cmd.retries = 0;
> + cmd.data = NULL;
> + cmd.error = 0;
> +
> + mrq.cmd = &cmd;
> + host->mrq = &mrq;
> + OMAP_HSMMC_WRITE(host->base, BLK, host->tuning_size);
> + set_data_timeout(host, 150000000, 0);
> + omap_hsmmc_start_command(host, &cmd, NULL);
> + host->cmd = NULL;
> + host->mrq = NULL;
> +
> + ret = wait_for_completion_timeout(&host->buf_ready,
> + msecs_to_jiffies(5000));
> + if (ret == 0) {
> + dev_err(mmc_dev(host->mmc), "Tuning BRR timeout");
> + ret = -ETIMEDOUT;
> + goto tuning_error;
> + }
> +

Please make use of mmc_send_tuning() which should simplfy some parts
of this code.

> + host->req_in_progress = false;
> +
> + cur_match = !memcmp(host->tuning_data, tuning_ref,
> + host->tuning_size);
> + if (cur_match) {
> + if (prev_match) {
> + length++;
> + } else {
> + start_window = phase_delay;
> + length = 1;
> + }
> + }
> +
> + if (length > max_len) {
> + max_window = start_window;
> + max_len = length;
> + }
> +
> + prev_match = cur_match;
> + phase_delay += 4;
> + }
> +
> + if (!max_len) {
> + dev_err(mmc_dev(host->mmc), "Unable to find match\n");
> + ret = -EIO;
> + goto tuning_error;
> + }
> +
> + val = OMAP_HSMMC_READ(host->base, AC12);
> + if (!(val & AC12_SCLK_SEL)) {
> + ret = -EIO;
> + goto tuning_error;
> + }
> +
> + phase_delay = max_window + 4 * (max_len >> 1);
> + omap_hsmmc_set_dll(host, phase_delay);
> +
> + omap_hsmmc_reset_controller_fsm(host, SRD);
> + omap_hsmmc_reset_controller_fsm(host, SRC);
> +
> + kfree(host->tuning_data);
> + return 0;
> +
> +tuning_error:
> + dev_err(mmc_dev(host->mmc),
> + "Tuning failed. Using fixed sampling clock\n");
> +
> + omap_hsmmc_disable_tuning(host);
> + omap_hsmmc_reset_controller_fsm(host, SRD);
> + omap_hsmmc_reset_controller_fsm(host, SRC);
> +
> + kfree(host->tuning_data);
> + return ret;
> +}
> +
> static struct mmc_host_ops omap_hsmmc_ops = {
> .post_req = omap_hsmmc_post_req,
> .pre_req = omap_hsmmc_pre_req,
> @@ -2046,6 +2274,7 @@ static struct mmc_host_ops omap_hsmmc_ops = {
> .enable_sdio_irq = omap_hsmmc_enable_sdio_irq,
> .start_signal_voltage_switch = omap_hsmmc_start_signal_voltage_switch,
> .card_busy = omap_hsmmc_card_busy,
> + .execute_tuning = omap_hsmmc_execute_tuning,
> };
>
> #ifdef CONFIG_DEBUG_FS
> @@ -2275,6 +2504,7 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
> mmc->f_max = OMAP_MMC_MAX_CLOCK;
>
> spin_lock_init(&host->irq_lock);
> + init_completion(&host->buf_ready);
>
> host->fclk = devm_clk_get(&pdev->dev, "fck");
> if (IS_ERR(host->fclk)) {
> --
> 1.7.9.5
>

Kind regards
Uffe
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Next message: Sudeep Holla: "Re: [PATCH v1 3/3] arm64: dts: add Hi6220 mailbox node"
Previous message: Marek Marczykowski-GÃrecki: "Re: [PATCH 3.12 49/82] xen/gntdevt: Fix race condition in gntdev_release()"
In reply to: Kishon Vijay Abraham I: "[PATCH v2 07/11] mmc: host: omap_hsmmc: add tuning support"
Next in thread: Kishon Vijay Abraham I: "[PATCH v2 08/11] mmc: host: omap_hsmmc: Workaround for errata id i802"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]