mmc: meson-gx: add SDIO interrupt support

Add SDIO interrupt support. Successfully tested on a S905X4-based
system (V3 register layout) with a BRCM4334 SDIO wifi module
(brcmfmac driver).

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Link: https://lore.kernel.org/r/27bffe3c-e579-3581-95e8-2587733487d2@gmail.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 8c40439..df05e60 100644 (file)
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -41,14 +41,17 @@
 #define   CLK_V2_TX_DELAY_MASK GENMASK(19, 16)
 #define   CLK_V2_RX_DELAY_MASK GENMASK(23, 20)
 #define   CLK_V2_ALWAYS_ON BIT(24)
+#define   CLK_V2_IRQ_SDIO_SLEEP BIT(25)
 
 #define   CLK_V3_TX_DELAY_MASK GENMASK(21, 16)
 #define   CLK_V3_RX_DELAY_MASK GENMASK(27, 22)
 #define   CLK_V3_ALWAYS_ON BIT(28)
+#define   CLK_V3_IRQ_SDIO_SLEEP BIT(29)
 
 #define   CLK_TX_DELAY_MASK(h)         (h->data->tx_delay_mask)
 #define   CLK_RX_DELAY_MASK(h)         (h->data->rx_delay_mask)
 #define   CLK_ALWAYS_ON(h)             (h->data->always_on)
+#define   CLK_IRQ_SDIO_SLEEP(h)                (h->data->irq_sdio_sleep)
 
 #define SD_EMMC_DELAY 0x4
 #define SD_EMMC_ADJUST 0x8
@@ -135,6 +138,7 @@ struct meson_mmc_data {
        unsigned int rx_delay_mask;
        unsigned int always_on;
        unsigned int adjust;
+       unsigned int irq_sdio_sleep;
 };
 
 struct sd_emmc_desc {
@@ -174,6 +178,7 @@ struct meson_host {
        bool vqmmc_enabled;
        bool needs_pre_post_req;
 
+       spinlock_t lock;
 };
 
 #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
@@ -430,6 +435,7 @@ static int meson_mmc_clk_init(struct meson_host *host)
        clk_reg |= FIELD_PREP(CLK_CORE_PHASE_MASK, CLK_PHASE_180);
        clk_reg |= FIELD_PREP(CLK_TX_PHASE_MASK, CLK_PHASE_0);
        clk_reg |= FIELD_PREP(CLK_RX_PHASE_MASK, CLK_PHASE_0);
+       clk_reg |= CLK_IRQ_SDIO_SLEEP(host);
        writel(clk_reg, host->regs + SD_EMMC_CLOCK);
 
        /* get the mux parents */
@@ -928,32 +934,54 @@ static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
        }
 }
 
+static void __meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+       struct meson_host *host = mmc_priv(mmc);
+       u32 reg_irqen = IRQ_EN_MASK;
+
+       if (enable)
+               reg_irqen |= IRQ_SDIO;
+       writel(reg_irqen, host->regs + SD_EMMC_IRQ_EN);
+}
+
 static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
 {
        struct meson_host *host = dev_id;
        struct mmc_command *cmd;
-       struct mmc_data *data;
        u32 status, raw_status;
        irqreturn_t ret = IRQ_NONE;
 
        raw_status = readl(host->regs + SD_EMMC_STATUS);
-       status = raw_status & IRQ_EN_MASK;
+       status = raw_status & (IRQ_EN_MASK | IRQ_SDIO);
 
        if (!status) {
                dev_dbg(host->dev,
                        "Unexpected IRQ! irq_en 0x%08lx - status 0x%08x\n",
-                        IRQ_EN_MASK, raw_status);
+                        IRQ_EN_MASK | IRQ_SDIO, raw_status);
                return IRQ_NONE;
        }
 
-       if (WARN_ON(!host) || WARN_ON(!host->cmd))
+       if (WARN_ON(!host))
                return IRQ_NONE;
 
        /* ack all raised interrupts */
        writel(status, host->regs + SD_EMMC_STATUS);
 
        cmd = host->cmd;
-       data = cmd->data;
+
+       if (status & IRQ_SDIO) {
+               spin_lock(&host->lock);
+               __meson_mmc_enable_sdio_irq(host->mmc, 0);
+               sdio_signal_irq(host->mmc);
+               spin_unlock(&host->lock);
+               status &= ~IRQ_SDIO;
+               if (!status)
+                       return IRQ_HANDLED;
+       }
+
+       if (WARN_ON(!cmd))
+               return IRQ_NONE;
+
        cmd->error = 0;
        if (status & IRQ_CRC_ERR) {
                dev_dbg(host->dev, "CRC Error - status 0x%08x\n", status);
@@ -971,12 +999,9 @@ static irqreturn_t meson_mmc_irq(int irq, void *dev_id)
 
        meson_mmc_read_resp(host->mmc, cmd);
 
-       if (status & IRQ_SDIO) {
-               dev_dbg(host->dev, "IRQ: SDIO TODO.\n");
-               ret = IRQ_HANDLED;
-       }
-
        if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
+               struct mmc_data *data = cmd->data;
+
                if (data && !cmd->error)
                        data->bytes_xfered = data->blksz * data->blocks;
                if (meson_mmc_bounce_buf_read(data) ||
@@ -1119,6 +1144,21 @@ static int meson_mmc_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios)
        return -EINVAL;
 }
 
+static void meson_mmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
+{
+       struct meson_host *host = mmc_priv(mmc);
+       unsigned long flags;
+
+       spin_lock_irqsave(&host->lock, flags);
+       __meson_mmc_enable_sdio_irq(mmc, enable);
+       spin_unlock_irqrestore(&host->lock, flags);
+}
+
+static void meson_mmc_ack_sdio_irq(struct mmc_host *mmc)
+{
+       meson_mmc_enable_sdio_irq(mmc, 1);
+}
+
 static const struct mmc_host_ops meson_mmc_ops = {
        .request        = meson_mmc_request,
        .set_ios        = meson_mmc_set_ios,
@@ -1128,6 +1168,8 @@ static const struct mmc_host_ops meson_mmc_ops = {
        .execute_tuning = meson_mmc_resampling_tuning,
        .card_busy      = meson_mmc_card_busy,
        .start_signal_voltage_switch = meson_mmc_voltage_switch,
+       .enable_sdio_irq = meson_mmc_enable_sdio_irq,
+       .ack_sdio_irq   = meson_mmc_ack_sdio_irq,
 };
 
 static int meson_mmc_probe(struct platform_device *pdev)
@@ -1233,7 +1275,13 @@ static int meson_mmc_probe(struct platform_device *pdev)
        if (ret)
                goto err_init_clk;
 
+       spin_lock_init(&host->lock);
+
        mmc->caps |= MMC_CAP_CMD23;
+
+       if (mmc->caps & MMC_CAP_SDIO_IRQ)
+               mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;
+
        if (host->dram_access_quirk) {
                /* Limit segments to 1 due to low available sram memory */
                mmc->max_segs = 1;
@@ -1324,6 +1372,7 @@ static const struct meson_mmc_data meson_gx_data = {
        .rx_delay_mask  = CLK_V2_RX_DELAY_MASK,
        .always_on      = CLK_V2_ALWAYS_ON,
        .adjust         = SD_EMMC_ADJUST,
+       .irq_sdio_sleep = CLK_V2_IRQ_SDIO_SLEEP,
 };
 
 static const struct meson_mmc_data meson_axg_data = {
@@ -1331,6 +1380,7 @@ static const struct meson_mmc_data meson_axg_data = {
        .rx_delay_mask  = CLK_V3_RX_DELAY_MASK,
        .always_on      = CLK_V3_ALWAYS_ON,
        .adjust         = SD_EMMC_V3_ADJUST,
+       .irq_sdio_sleep = CLK_V3_IRQ_SDIO_SLEEP,
 };
 
 static const struct of_device_id meson_mmc_of_match[] = {