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Subject[RFC PATCH 2/3] mmc: omap_hsmmc: add tuning support
Date
From: Balaji T K <balajitk@ti.com>

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: Viswanath Puttagunta <vishp@ti.com>
Signed-off-by: Sourav Poddar <sourav.poddar@ti.com>
[ kishon@ti.com : Set the functional clock to 192MHz if the contoller
supports HS200 ]
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
drivers/mmc/host/omap_hsmmc.c | 325 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 322 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 2e42ed3..675bd31d 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -22,6 +22,7 @@
#include <linux/dmaengine.h>
#include <linux/seq_file.h>
#include <linux/sizes.h>
+#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
@@ -47,6 +48,7 @@
/* 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
@@ -100,6 +102,7 @@
#define CLKEXTFREE (1 << 16)
#define CTPL (1 << 11)
#define DW8 (1 << 5)
+#define BRR (1 << 5)
#define OD 0x1
#define STAT_CLEAR 0xFFFFFFFF
#define INIT_STREAM_CMD 0x00000000
@@ -129,6 +132,20 @@
#define CERR_EN (1 << 28)
#define BADA_EN (1 << 29)

+#define V1V8_SIGEN (1 << 19)
+#define AC12_SCLK_SEL (1 << 23)
+#define AC12_UHSMC_MASK (7 << 16)
+#define AC12_UHSMC_SDR50 (2 << 16)
+#define AC12_UHSMC_SDR104 (3 << 16)
+#define DLL_LOCK (1 << 0)
+#define DLL_CALIB (1 << 1)
+#define DLL_UNLOCK_STICKY (1 << 2)
+#define DLL_SWT (1 << 20)
+#define DLL_FORCE_SR_C_MASK (0x7F << 13)
+#define DLL_FORCE_SR_C_SHIFT 13
+#define DLL_FORCE_VALUE (1 << 12)
+#define DLL_RESET (1 << 31)
+
#define INT_EN_MASK (BADA_EN | CERR_EN | ACE_EN | DEB_EN | DCRC_EN |\
DTO_EN | CIE_EN | CEB_EN | CCRC_EN | CTO_EN | \
BRR_EN | BWR_EN | TC_EN | CC_EN)
@@ -143,18 +160,23 @@
#define SDR50 (1 << 0)
#define SDR104 (1 << 1)
#define DDR50 (1 << 2)
+#define CAPA2_TSDR50 (1 << 13)

#define MMC_AUTOSUSPEND_DELAY 100
#define MMC_TIMEOUT_MS 20 /* 20 mSec */
#define MMC_TIMEOUT_US 20000 /* 20000 micro Sec */
#define OMAP_MMC_MIN_CLOCK 400000
#define OMAP_MMC_MAX_CLOCK 52000000
+#define MAX_PHASE_DELAY 0x7F
#define DRIVER_NAME "omap_hsmmc"

#define VDD_1V8 1800000 /* 180000 uV */
#define VDD_3V0 3000000 /* 300000 uV */
#define VDD_165_195 (ffs(MMC_VDD_165_195) - 1)

+#define EMMC_HSDDR_SD_SDR25_MAX 52000000
+#define SD_SDR50_MAX_FREQ 104000000
+
/*
* One controller can have multiple slots, like on some omap boards using
* omap.c controller driver. Luckily this is not currently done on any known
@@ -198,6 +220,7 @@ struct omap_hsmmc_host {
void __iomem *base;
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;
@@ -224,6 +247,13 @@ struct omap_hsmmc_host {
#define AUTO_CMD23 (1 << 0) /* Auto CMD23 support */
#define HSMMC_SDIO_IRQ_ENABLED (1 << 1) /* SDIO irq enabled */
#define HSMMC_WAKE_IRQ_ENABLED (1 << 2)
+
+ u32 *tuning_data;
+ int tuning_size;
+ int tuning_done;
+ int tuning_fsrc;
+ u32 tuning_uhsmc;
+ u32 tuning_opcode;
struct omap_hsmmc_next next_data;
struct omap_mmc_platform_data *pdata;
};
@@ -233,6 +263,48 @@ struct omap_mmc_of_data {
u8 controller_flags;
};

+static const u32 ref_tuning_4bits[] = {
+ 0x00FF0FFF, 0xCCC3CCFF, 0xFFCC3CC3, 0xEFFEFFFE,
+ 0xDDFFDFFF, 0xFBFFFBFF, 0xFF7FFFBF, 0xEFBDF777,
+ 0xF0FFF0FF, 0x3CCCFC0F, 0xCFCC33CC, 0xEEFFEFFF,
+ 0xFDFFFDFF, 0xFFBFFFDF, 0xFFF7FFBB, 0xDE7B7FF7
+};
+
+static const u32 ref_tuning_8bits[] = {
+ 0xFF00FFFF, 0x0000FFFF, 0xCCCCFFFF, 0xCCCC33CC,
+ 0xCC3333CC, 0xFFFFCCCC, 0xFFFFEEFF, 0xFFEEEEFF,
+ 0xFFDDFFFF, 0xDDDDFFFF, 0xBBFFFFFF, 0xBBFFFFFF,
+ 0xFFFFFFBB, 0XFFFFFF77, 0x77FF7777, 0xFFEEDDBB,
+ 0x00FFFFFF, 0x00FFFFFF, 0xCCFFFF00, 0xCC33CCCC,
+ 0x3333CCCC, 0xFFCCCCCC, 0xFFEEFFFF, 0xEEEEFFFF,
+ 0xDDFFFFFF, 0xDDFFFFFF, 0xFFFFFFDD, 0XFFFFFFBB,
+ 0xFFFFBBBB, 0xFFFF77FF, 0xFF7777FF, 0xEEDDBB77
+};
+
+static inline int 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_SR_C_MASK);
+ dll &= ~DLL_CALIB;
+ dll |= (count << DLL_FORCE_SR_C_SHIFT);
+ OMAP_HSMMC_WRITE(host->base, DLL, dll);
+ dll |= DLL_FORCE_VALUE;
+ 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;
+ dll = OMAP_HSMMC_READ(host->base, DLL);
+
+ return 0;
+}
+
static void omap_hsmmc_start_dma_transfer(struct omap_hsmmc_host *host);

static int omap_hsmmc_card_detect(struct device *dev, int slot)
@@ -531,7 +603,10 @@ static void omap_hsmmc_enable_irq(struct omap_hsmmc_host *host,
u32 irq_mask = INT_EN_MASK;
unsigned long flags;

- if (host->use_dma)
+ if ((cmd->opcode == MMC_SEND_TUNING_BLOCK) ||
+ (cmd->opcode == MMC_SEND_TUNING_BLOCK_HS200))
+ irq_mask |= BRR_EN;
+ else if (host->use_dma)
irq_mask &= ~(BRR_EN | BWR_EN);

/* Disable timeout for erases */
@@ -578,6 +653,33 @@ static u16 calc_divisor(struct omap_hsmmc_host *host, struct mmc_ios *ios)
return dsor;
}

+static inline int omap_hsmmc_restore_dll(struct omap_hsmmc_host *host)
+{
+ u32 ac12;
+ u32 dll;
+
+ ac12 = OMAP_HSMMC_READ(host->base, AC12);
+ ac12 |= host->tuning_uhsmc;
+ OMAP_HSMMC_WRITE(host->base, AC12, ac12);
+
+ dll = OMAP_HSMMC_READ(host->base, DLL);
+ dll |= DLL_FORCE_VALUE;
+ OMAP_HSMMC_WRITE(host->base, DLL, dll);
+
+ if (omap_hsmmc_set_dll(host, host->tuning_fsrc))
+ return -EIO;
+ return 0;
+}
+
+static inline void omap_hsmmc_save_dll(struct omap_hsmmc_host *host)
+{
+ u32 ac12;
+
+ ac12 = OMAP_HSMMC_READ(host->base, AC12);
+ ac12 &= ~AC12_UHSMC_MASK;
+ OMAP_HSMMC_WRITE(host->base, AC12, ac12);
+}
+
static void omap_hsmmc_set_clock(struct omap_hsmmc_host *host)
{
struct mmc_ios *ios = &host->mmc->ios;
@@ -589,6 +691,9 @@ static void omap_hsmmc_set_clock(struct omap_hsmmc_host *host)

omap_hsmmc_stop_clock(host);

+ if (host->mmc->caps2 & MMC_CAP2_HS200)
+ clk_set_rate(host->fclk, 192000000);
+
regval = OMAP_HSMMC_READ(host->base, SYSCTL);
regval = regval & ~(CLKD_MASK | DTO_MASK);
clkdiv = calc_divisor(host, ios);
@@ -667,7 +772,6 @@ static void omap_hsmmc_set_bus_mode(struct omap_hsmmc_host *host)
}

#ifdef CONFIG_PM
-
/*
* Restore the MMC host context, if it was lost as result of a
* power state change.
@@ -878,6 +982,12 @@ omap_hsmmc_start_command(struct omap_hsmmc_host *host, struct mmc_command *cmd,
if (host->use_dma)
cmdreg |= DMAE;

+ /* 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 = (cmd->opcode << 24) | (resptype << 16) |
+ (cmdtype << 22) | DP_SELECT | DDIR;
+ }
host->req_in_progress = 1;

OMAP_HSMMC_WRITE(host->base, ARG, cmd->arg);
@@ -965,6 +1075,9 @@ omap_hsmmc_cmd_done(struct omap_hsmmc_host *host, struct mmc_command *cmd)
return;
}

+ if (host->cmd->opcode == MMC_SEND_TUNING_BLOCK)
+ return;
+
host->cmd = NULL;

if (cmd->flags & MMC_RSP_PRESENT) {
@@ -1104,6 +1217,7 @@ 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 = 0;

data = host->data;
dev_vdbg(mmc_dev(host->mmc), "IRQ Status is %x\n", status);
@@ -1139,6 +1253,15 @@ static void omap_hsmmc_do_irq(struct omap_hsmmc_host *host, int status)
}

OMAP_HSMMC_WRITE(host->base, STAT, 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);
+ return;
+ }
+
if (end_cmd || ((status & CC_EN) && host->cmd))
omap_hsmmc_cmd_done(host, host->cmd);
if ((end_trans || (status & TC_EN)) && host->mrq)
@@ -1844,6 +1967,189 @@ static int omap_hsmmc_multi_io_quirk(struct mmc_card *card,
return blk_size;
}

+static int omap_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+ struct omap_hsmmc_host *host;
+ struct mmc_ios *ios = &mmc->ios;
+ const u32 *tuning_ref;
+ int phase_delay = 0;
+ int err = 0;
+ int count = 0;
+ int length = 0;
+ int note_index = 0xFF;
+ int max_index = 0;
+ int max_window = 0;
+ bool previous_match = false;
+ bool current_match;
+ u32 ac12, capa2, dll = 0;
+
+ host = mmc_priv(mmc);
+ 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;
+
+ host->tuning_done = 0;
+ /* clock tuning is not needed for upto 52MHz */
+ if (ios->clock <= EMMC_HSDDR_SD_SDR25_MAX)
+ return 0;
+
+ omap_hsmmc_stop_clock(host);
+
+ ac12 = OMAP_HSMMC_READ(host->base, AC12);
+ capa2 = OMAP_HSMMC_READ(host->base, CAPA2);
+
+ ac12 &= ~AC12_UHSMC_MASK;
+ OMAP_HSMMC_WRITE(host->base, AC12, ac12);
+
+ /*
+ * Host Controller needs tuning only in case of SDR104 mode
+ * and for SDR50 mode when Use Tuning for SDR50 is set in
+ * Capabilities register.
+ */
+ if (ios->clock <= SD_SDR50_MAX_FREQ) {
+ if (!(capa2 & CAPA2_TSDR50))
+ return 0;
+ ac12 |= AC12_UHSMC_SDR50;
+ } else {
+ ac12 |= AC12_UHSMC_SDR104;
+ }
+
+ ac12 |= AC12_UHSMC_SDR104;
+ ac12 |= V1V8_SIGEN;
+
+ /* Enable SDR50/SDR104 mode */
+ OMAP_HSMMC_WRITE(host->base, AC12, ac12);
+ omap_hsmmc_start_clock(host);
+
+ /* Start software tuning Procedure */
+ dll |= DLL_SWT;
+ OMAP_HSMMC_WRITE(host->base, DLL, dll);
+
+ while (phase_delay < MAX_PHASE_DELAY) {
+ struct mmc_command cmd = {0};
+ struct mmc_request mrq = {0};
+
+ if (phase_delay > MAX_PHASE_DELAY)
+ break;
+
+ 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, 50000000, 0);
+ omap_hsmmc_start_command(host, &cmd, NULL);
+
+ host->cmd = NULL;
+ host->mrq = NULL;
+
+ /* Wait for Buffer Read Ready interrupt */
+ err = wait_for_completion_timeout(&host->buf_ready,
+ msecs_to_jiffies(5000));
+ omap_hsmmc_disable_irq(host);
+ host->req_in_progress = 0;
+
+ if (err == 0) {
+ dev_err(mmc_dev(host->mmc),
+ "Tuning BRR timeout. phase_delay=%x",
+ phase_delay);
+ err = -ETIMEDOUT;
+ goto tuning_error;
+ }
+
+ current_match = true;
+ if (memcmp(host->tuning_data, tuning_ref, host->tuning_size))
+ current_match = false;
+ else
+ current_match = true;
+
+ if (current_match == true) {
+ if (previous_match == false) {
+ /* new window */
+ note_index = count;
+ length = 1;
+ } else {
+ length++;
+ }
+ previous_match = true;
+ if (length > max_window) {
+ max_index = note_index;
+ max_window = length;
+ }
+ } else {
+ previous_match = false;
+ }
+ phase_delay += 4;
+ count++;
+ }
+
+ if (!max_window) {
+ dev_err(mmc_dev(host->mmc), "Unable to find match\n");
+ err = -EIO;
+ goto tuning_error;
+ }
+
+ ac12 = OMAP_HSMMC_READ(host->base, AC12);
+ if (!(ac12 & AC12_SCLK_SEL)) {
+ err = -EIO;
+ goto tuning_error;
+ }
+
+ dll = OMAP_HSMMC_READ(host->base, DLL);
+ dll &= ~DLL_SWT;
+ OMAP_HSMMC_WRITE(host->base, DLL, dll);
+ count = 4 * (max_index + (max_window >> 1));
+ if (omap_hsmmc_set_dll(host, count)) {
+ err = -EIO;
+ goto tuning_error;
+ }
+ host->tuning_fsrc = count;
+ host->tuning_uhsmc = (OMAP_HSMMC_READ(host->base, AC12)
+ & AC12_UHSMC_MASK);
+ host->tuning_opcode = opcode;
+ host->tuning_done = 1;
+ omap_hsmmc_reset_controller_fsm(host, SRD);
+ omap_hsmmc_reset_controller_fsm(host, SRC);
+
+ return 0;
+
+tuning_error:
+ dev_err(mmc_dev(host->mmc),
+ "Tuning failed. Using fixed sampling clock\n");
+ ac12 = OMAP_HSMMC_READ(host->base, AC12);
+ ac12 &= ~(AC12_UHSMC_MASK | AC12_SCLK_SEL);
+ OMAP_HSMMC_WRITE(host->base, AC12, ac12);
+
+ dll = OMAP_HSMMC_READ(host->base, DLL);
+ dll &= ~(DLL_FORCE_VALUE | DLL_SWT);
+ OMAP_HSMMC_WRITE(host->base, DLL, dll);
+
+ omap_hsmmc_reset_controller_fsm(host, SRD);
+ omap_hsmmc_reset_controller_fsm(host, SRC);
+ return err;
+}
+
static struct mmc_host_ops omap_hsmmc_ops = {
.enable = omap_hsmmc_enable_fclk,
.disable = omap_hsmmc_disable_fclk,
@@ -1855,6 +2161,7 @@ static struct mmc_host_ops omap_hsmmc_ops = {
.get_ro = omap_hsmmc_get_ro,
.init_card = omap_hsmmc_init_card,
.enable_sdio_irq = omap_hsmmc_enable_sdio_irq,
+ .execute_tuning = omap_execute_tuning,
};

#ifdef CONFIG_DEBUG_FS
@@ -2107,6 +2414,7 @@ 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)) {
@@ -2159,7 +2467,7 @@ static int omap_hsmmc_probe(struct platform_device *pdev)

mmc->pm_caps = mmc_slot(host).pm_caps;

- reg = OMAP_HSMMC_READ(host->base, OMAP_HSMMC_CAPA2);
+ reg = OMAP_HSMMC_READ(host->base, CAPA2);

if (reg & SDR50)
mmc->caps |= MMC_CAP_UHS_DDR50;
@@ -2172,6 +2480,9 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
if (reg & DDR50)
mmc->caps |= MMC_CAP_UHS_DDR50;

+ mmc->caps |= MMC_CAP_DRIVER_TYPE_A | MMC_CAP_DRIVER_TYPE_C |
+ MMC_CAP_DRIVER_TYPE_D;
+
omap_hsmmc_conf_bus_power(host);

if (!pdev->dev.of_node) {
@@ -2380,6 +2691,7 @@ static int omap_hsmmc_suspend(struct device *dev)
OMAP_HSMMC_WRITE(host->base, HCTL,
OMAP_HSMMC_READ(host->base, HCTL) & ~SDBP);
}
+ host->tuning_done = 0;

/* do not wake up due to sdio irq */
if ((host->mmc->caps & MMC_CAP_SDIO_IRQ) &&
@@ -2434,6 +2746,9 @@ static int omap_hsmmc_runtime_suspend(struct device *dev)
int ret = 0;

host = platform_get_drvdata(to_platform_device(dev));
+ if (host->tuning_done)
+ omap_hsmmc_restore_dll(host);
+
omap_hsmmc_context_save(host);
dev_dbg(dev, "disabled\n");

@@ -2480,6 +2795,10 @@ static int omap_hsmmc_runtime_resume(struct device *dev)

host = platform_get_drvdata(to_platform_device(dev));
omap_hsmmc_context_restore(host);
+
+ if (host->tuning_done)
+ omap_hsmmc_restore_dll(host);
+
dev_dbg(dev, "enabled\n");

spin_lock_irqsave(&host->irq_lock, flags);
--
1.7.9.5


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