[PATCH v2 3/3] mmc: sdio: mediatek: Support SDIO feature

From: Yong Mao
Date: Tue Apr 18 2017 - 06:14:03 EST

From: yong mao <yong.mao@xxxxxxxxxxxx>

1. Add irqlock to protect accessing the shared register
2. Implement enable_sdio_irq interface
3. Add msdc_recheck_sdio_irq mechanism to make sure all interrupts
can be processed immediately

Signed-off-by: Yong Mao <yong.mao@xxxxxxxxxxxx>
Signed-off-by: Chaotian Jing <chaotian.jing@xxxxxxxxxxxx>
---
drivers/mmc/host/mtk-sd.c | 182 +++++++++++++++++++++++++++++++++++----------
1 file changed, 143 insertions(+), 39 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 07f3236..fdae197 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -118,6 +118,7 @@
#define MSDC_PS_CDSTS (0x1 << 1) /* R */
#define MSDC_PS_CDDEBOUNCE (0xf << 12) /* RW */
#define MSDC_PS_DAT (0xff << 16) /* R */
+#define MSDC_PS_DATA1 (0x1 << 17) /* R */
#define MSDC_PS_CMD (0x1 << 24) /* R */
#define MSDC_PS_WP (0x1 << 31) /* R */

@@ -312,6 +313,7 @@ struct msdc_host {
int cmd_rsp;

spinlock_t lock;
+ spinlock_t irqlock; /* irq lock */
struct mmc_request *mrq;
struct mmc_command *cmd;
struct mmc_data *data;
@@ -330,12 +332,14 @@ struct msdc_host {
struct pinctrl_state *pins_uhs;
struct delayed_work req_timeout;
int irq; /* host interrupt */
+ bool irq_thread_alive;

struct clk *src_clk; /* msdc source clock */
struct clk *h_clk; /* msdc h_clk */
u32 mclk; /* mmc subsystem clock frequency */
u32 src_clk_freq; /* source clock frequency */
u32 sclk; /* SD/MS bus clock frequency */
+ bool clock_on;
unsigned char timing;
bool vqmmc_enabled;
u32 hs400_ds_delay;
@@ -343,6 +347,7 @@ struct msdc_host {
u32 hs400_cmd_int_delay; /* cmd internal delay for HS400 */
bool hs400_cmd_resp_sel_rising;
/* cmd response sample selection for HS400 */
+ u32 clk_pad_delay;
bool hs400_mode; /* current eMMC will run at hs400 mode */
struct msdc_save_para save_para; /* used when gate HCLK */
struct msdc_tune_para def_tune_para; /* default tune setting */
@@ -399,6 +404,7 @@ static void msdc_reset_hw(struct msdc_host *host)

static void msdc_cmd_next(struct msdc_host *host,
struct mmc_request *mrq, struct mmc_command *cmd);
+static void msdc_recheck_sdio_irq(struct msdc_host *host);

static const u32 cmd_ints_mask = MSDC_INTEN_CMDRDY | MSDC_INTEN_RSPCRCERR |
MSDC_INTEN_CMDTMO | MSDC_INTEN_ACMDRDY |
@@ -525,6 +531,7 @@ static void msdc_gate_clock(struct msdc_host *host)
{
clk_disable_unprepare(host->src_clk);
clk_disable_unprepare(host->h_clk);
+ host->clock_on = false;
}

static void msdc_ungate_clock(struct msdc_host *host)
@@ -533,6 +540,7 @@ static void msdc_ungate_clock(struct msdc_host *host)
clk_prepare_enable(host->src_clk);
while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
cpu_relax();
+ host->clock_on = true;
}

static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
@@ -541,6 +549,7 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
u32 flags;
u32 div;
u32 sclk;
+ unsigned long irq_flags;

if (!hz) {
dev_dbg(host->dev, "set mclk to 0\n");
@@ -549,8 +558,11 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
return;
}

+ spin_lock_irqsave(&host->irqlock, irq_flags);
flags = readl(host->base + MSDC_INTEN);
sdr_clr_bits(host->base + MSDC_INTEN, flags);
+ spin_unlock_irqrestore(&host->irqlock, irq_flags);
+
sdr_clr_bits(host->base + MSDC_CFG, MSDC_CFG_HS400_CK_MODE);
if (timing == MMC_TIMING_UHS_DDR50 ||
timing == MMC_TIMING_MMC_DDR52 ||
@@ -600,7 +612,10 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
host->timing = timing;
/* need because clk changed. */
msdc_set_timeout(host, host->timeout_ns, host->timeout_clks);
+
+ spin_lock_irqsave(&host->irqlock, irq_flags);
sdr_set_bits(host->base + MSDC_INTEN, flags);
+ spin_unlock_irqrestore(&host->irqlock, irq_flags);

/*
* mmc_select_hs400() will drop to 50Mhz and High speed mode,
@@ -708,6 +723,7 @@ static inline u32 msdc_cmd_prepare_raw_cmd(struct msdc_host *host,
static void msdc_start_data(struct msdc_host *host, struct mmc_request *mrq,
struct mmc_command *cmd, struct mmc_data *data)
{
+ unsigned long flags;
bool read;

WARN_ON(host->data);
@@ -716,8 +732,12 @@ static void msdc_start_data(struct msdc_host *host, struct mmc_request *mrq,

mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);
msdc_dma_setup(host, &host->dma, data);
+
+ spin_lock_irqsave(&host->irqlock, flags);
sdr_set_bits(host->base + MSDC_INTEN, data_ints_mask);
sdr_set_field(host->base + MSDC_DMA_CTRL, MSDC_DMA_CTRL_START, 1);
+ spin_unlock_irqrestore(&host->irqlock, flags);
+
dev_dbg(host->dev, "DMA start\n");
dev_dbg(host->dev, "%s: cmd=%d DMA data: %d blocks; read=%d\n",
__func__, cmd->opcode, data->blocks, read);
@@ -774,6 +794,8 @@ static void msdc_request_done(struct msdc_host *host, struct mmc_request *mrq)
if (mrq->data)
msdc_unprepare_data(host, mrq);
mmc_request_done(host->mmc, mrq);
+
+ msdc_recheck_sdio_irq(host);
}

/* returns true if command is fully handled; returns false otherwise */
@@ -797,15 +819,17 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
| MSDC_INT_CMDTMO)))
return done;

- spin_lock_irqsave(&host->lock, flags);
done = !host->cmd;
+ spin_lock_irqsave(&host->lock, flags);
host->cmd = NULL;
spin_unlock_irqrestore(&host->lock, flags);

if (done)
return true;

+ spin_lock_irqsave(&host->irqlock, flags);
sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);
+ spin_unlock_irqrestore(&host->irqlock, flags);

if (cmd->flags & MMC_RSP_PRESENT) {
if (cmd->flags & MMC_RSP_136) {
@@ -883,6 +907,7 @@ static inline bool msdc_cmd_is_ready(struct msdc_host *host,
static void msdc_start_command(struct msdc_host *host,
struct mmc_request *mrq, struct mmc_command *cmd)
{
+ unsigned long flags;
u32 rawcmd;

WARN_ON(host->cmd);
@@ -901,7 +926,10 @@ static void msdc_start_command(struct msdc_host *host,
rawcmd = msdc_cmd_prepare_raw_cmd(host, mrq, cmd);
mod_delayed_work(system_wq, &host->req_timeout, DAT_TIMEOUT);

+ spin_lock_irqsave(&host->irqlock, flags);
sdr_set_bits(host->base + MSDC_INTEN, cmd_ints_mask);
+ spin_unlock_irqrestore(&host->irqlock, flags);
+
writel(cmd->arg, host->base + SDC_ARG);
writel(rawcmd, host->base + SDC_CMD);
}
@@ -993,8 +1021,8 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
| MSDC_INT_DMA_BDCSERR | MSDC_INT_DMA_GPDCSERR
| MSDC_INT_DMA_PROTECT);

- spin_lock_irqsave(&host->lock, flags);
done = !host->data;
+ spin_lock_irqsave(&host->lock, flags);
if (check_data)
host->data = NULL;
spin_unlock_irqrestore(&host->lock, flags);
@@ -1009,7 +1037,11 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
1);
while (readl(host->base + MSDC_DMA_CFG) & MSDC_DMA_CFG_STS)
cpu_relax();
+
+ spin_lock_irqsave(&host->irqlock, flags);
sdr_clr_bits(host->base + MSDC_INTEN, data_ints_mask);
+ spin_unlock_irqrestore(&host->irqlock, flags);
+
dev_dbg(host->dev, "DMA stop\n");

if ((events & MSDC_INT_XFER_COMPL) && (!stop || !stop->error)) {
@@ -1123,44 +1155,47 @@ static void msdc_request_timeout(struct work_struct *work)

static irqreturn_t msdc_irq(int irq, void *dev_id)
{
+ unsigned long flags;
struct msdc_host *host = (struct msdc_host *) dev_id;
+ struct mmc_request *mrq;
+ struct mmc_command *cmd;
+ struct mmc_data *data;
+ u32 events, event_mask;
+
+ spin_lock_irqsave(&host->irqlock, flags);
+ events = readl(host->base + MSDC_INT);
+ event_mask = readl(host->base + MSDC_INTEN);
+ /* clear interrupts */
+ writel(events & event_mask, host->base + MSDC_INT);
+
+ mrq = host->mrq;
+ cmd = host->cmd;
+ data = host->data;
+ spin_unlock_irqrestore(&host->irqlock, flags);
+
+ if ((events & event_mask) & MSDC_INT_SDIOIRQ) {
+ mmc_signal_sdio_irq(host->mmc);
+ if (!mrq)
+ return IRQ_HANDLED;
+ }

- while (true) {
- unsigned long flags;
- struct mmc_request *mrq;
- struct mmc_command *cmd;
- struct mmc_data *data;
- u32 events, event_mask;
-
- spin_lock_irqsave(&host->lock, flags);
- events = readl(host->base + MSDC_INT);
- event_mask = readl(host->base + MSDC_INTEN);
- /* clear interrupts */
- writel(events & event_mask, host->base + MSDC_INT);
-
- mrq = host->mrq;
- cmd = host->cmd;
- data = host->data;
- spin_unlock_irqrestore(&host->lock, flags);
-
- if (!(events & event_mask))
- break;
+ if (!(events & (event_mask & ~MSDC_INT_SDIOIRQ)))
+ return IRQ_HANDLED;

- if (!mrq) {
- dev_err(host->dev,
- "%s: MRQ=NULL; events=%08X; event_mask=%08X\n",
- __func__, events, event_mask);
- WARN_ON(1);
- break;
- }
+ if (!mrq) {
+ dev_err(host->dev,
+ "%s: MRQ=NULL; events=%08X; event_mask=%08X\n",
+ __func__, events, event_mask);
+ WARN_ON(1);
+ return IRQ_HANDLED;
+ }

- dev_dbg(host->dev, "%s: events=%08X\n", __func__, events);
+ dev_dbg(host->dev, "%s: events=%08X\n", __func__, events);

- if (cmd)
- msdc_cmd_done(host, events, mrq, cmd);
- else if (data)
- msdc_data_xfer_done(host, events, mrq, data);
- }
+ if (cmd)
+ msdc_cmd_done(host, events, mrq, cmd);
+ else if (data)
+ msdc_data_xfer_done(host, events, mrq, data);

return IRQ_HANDLED;
}
@@ -1168,6 +1203,7 @@ static irqreturn_t msdc_irq(int irq, void *dev_id)
static void msdc_init_hw(struct msdc_host *host)
{
u32 val;
+ unsigned long flags;

/* Configure to MMC/SD mode, clock free running */
sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_MODE | MSDC_CFG_CKPDN);
@@ -1179,11 +1215,14 @@ static void msdc_init_hw(struct msdc_host *host)
sdr_clr_bits(host->base + MSDC_PS, MSDC_PS_CDEN);

/* Disable and clear all interrupts */
+ spin_lock_irqsave(&host->irqlock, flags);
writel(0, host->base + MSDC_INTEN);
val = readl(host->base + MSDC_INT);
writel(val, host->base + MSDC_INT);
+ spin_unlock_irqrestore(&host->irqlock, flags);

- writel(0, host->base + MSDC_PAD_TUNE);
+ sdr_set_field(host->base + MSDC_PAD_TUNE,
+ MSDC_PAD_TUNE_CLKTDLY, host->clk_pad_delay);
writel(0, host->base + MSDC_IOCON);
sdr_set_field(host->base + MSDC_IOCON, MSDC_IOCON_DDLSEL, 0);
writel(0x403c0046, host->base + MSDC_PATCH_BIT);
@@ -1196,9 +1235,11 @@ static void msdc_init_hw(struct msdc_host *host)
*/
sdr_set_bits(host->base + SDC_CFG, SDC_CFG_SDIO);

- /* disable detect SDIO device interrupt function */
- sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
-
+ if (host->mmc->caps & MMC_CAP_SDIO_IRQ)
+ sdr_set_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
+ else
+ /* disable detect SDIO device interrupt function */
+ sdr_clr_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
/* Configure to default data timeout */
sdr_set_field(host->base + SDC_CFG, SDC_CFG_DTOC, 3);

@@ -1210,11 +1251,15 @@ static void msdc_init_hw(struct msdc_host *host)
static void msdc_deinit_hw(struct msdc_host *host)
{
u32 val;
+ unsigned long flags;
+
/* Disable and clear all interrupts */
+ spin_lock_irqsave(&host->irqlock, flags);
writel(0, host->base + MSDC_INTEN);

val = readl(host->base + MSDC_INT);
writel(val, host->base + MSDC_INT);
+ spin_unlock_irqrestore(&host->irqlock, flags);
}

/* init gpd and bd list in msdc_drv_probe */
@@ -1582,6 +1627,48 @@ static void msdc_hw_reset(struct mmc_host *mmc)
sdr_clr_bits(host->base + EMMC_IOCON, 1);
}

+/**
+ * msdc_recheck_sdio_irq - recheck whether the SDIO IRQ is lost
+ * @host: The host to check.
+ *
+ * Host controller may lost interrupt in some special case.
+ * Add sdio IRQ recheck mechanism to make sure all interrupts
+ * can be processed immediately
+ */
+static void msdc_recheck_sdio_irq(struct msdc_host *host)
+{
+ u32 reg_int, reg_ps;
+
+ if (host->clock_on && (host->mmc->caps & MMC_CAP_SDIO_IRQ) &&
+ host->irq_thread_alive) {
+ reg_int = readl(host->base + MSDC_INT);
+ reg_ps = readl(host->base + MSDC_PS);
+ if (!((reg_int & MSDC_INT_SDIOIRQ) ||
+ (reg_ps & MSDC_PS_DATA1)))
+ mmc_signal_sdio_irq(host->mmc);
+ }
+}
+
+static void msdc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+ unsigned long flags;
+ struct msdc_host *host = mmc_priv(mmc);
+
+ host->irq_thread_alive = true;
+ if (enable) {
+ msdc_recheck_sdio_irq(host);
+
+ spin_lock_irqsave(&host->irqlock, flags);
+ sdr_set_bits(host->base + SDC_CFG, SDC_CFG_SDIOIDE);
+ sdr_set_bits(host->base + MSDC_INTEN, MSDC_INTEN_SDIOIRQ);
+ spin_unlock_irqrestore(&host->irqlock, flags);
+ } else {
+ spin_lock_irqsave(&host->irqlock, flags);
+ sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INTEN_SDIOIRQ);
+ spin_unlock_irqrestore(&host->irqlock, flags);
+ }
+}
+
static struct mmc_host_ops mt_msdc_ops = {
.post_req = msdc_post_req,
.pre_req = msdc_pre_req,
@@ -1593,6 +1680,7 @@ static void msdc_hw_reset(struct mmc_host *mmc)
.execute_tuning = msdc_execute_tuning,
.prepare_hs400_tuning = msdc_prepare_hs400_tuning,
.hw_reset = msdc_hw_reset,
+ .enable_sdio_irq = msdc_enable_sdio_irq,
};

static void msdc_of_property_parse(struct platform_device *pdev,
@@ -1612,6 +1700,9 @@ static void msdc_of_property_parse(struct platform_device *pdev,
host->hs400_cmd_resp_sel_rising = true;
else
host->hs400_cmd_resp_sel_rising = false;
+
+ of_property_read_u32(pdev->dev.of_node, "mediatek,clk-pad-delay",
+ &host->clk_pad_delay);
}

static int msdc_drv_probe(struct platform_device *pdev)
@@ -1705,6 +1796,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
mmc_dev(mmc)->dma_mask = &host->dma_mask;

host->timeout_clks = 3 * 1048576;
+ host->irq_thread_alive = false;
host->dma.gpd = dma_alloc_coherent(&pdev->dev,
2 * sizeof(struct mt_gpdma_desc),
&host->dma.gpd_addr, GFP_KERNEL);
@@ -1718,6 +1810,7 @@ static int msdc_drv_probe(struct platform_device *pdev)
msdc_init_gpd_bd(host, &host->dma);
INIT_DELAYED_WORK(&host->req_timeout, msdc_request_timeout);
spin_lock_init(&host->lock);
+ spin_lock_init(&host->irqlock);

platform_set_drvdata(pdev, mmc);
msdc_ungate_clock(host);
@@ -1732,6 +1825,10 @@ static int msdc_drv_probe(struct platform_device *pdev)
pm_runtime_set_autosuspend_delay(host->dev, MTK_MMC_AUTOSUSPEND_DELAY);
pm_runtime_use_autosuspend(host->dev);
pm_runtime_enable(host->dev);
+
+ /* In SDIO irq mode, DATA1 slways need to be detected */
+ if (host->mmc->caps & MMC_CAP_SDIO_IRQ)
+ pm_runtime_get_sync(host->dev);
ret = mmc_add_host(mmc);

if (ret)
@@ -1821,6 +1918,10 @@ static int msdc_runtime_suspend(struct device *dev)

msdc_save_reg(host);
msdc_gate_clock(host);
+ if (host->mmc->caps & MMC_CAP_SDIO_IRQ) {
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+ }
return 0;
}

@@ -1829,6 +1930,9 @@ static int msdc_runtime_resume(struct device *dev)
struct mmc_host *mmc = dev_get_drvdata(dev);
struct msdc_host *host = mmc_priv(mmc);

+ /* In SDIO irq mode, DATA1 slways need to be detected */
+ if (host->mmc->caps & MMC_CAP_SDIO_IRQ)
+ pm_runtime_get_sync(host->dev);
msdc_ungate_clock(host);
msdc_restore_reg(host);
return 0;
--
1.7.9.5