Re: [PATCH v1 1/1] mmc: sdhci-of-dwcmshc: Add CQE support
From: Shawn Lin
Date: Mon Aug 28 2023 - 03:49:35 EST
+Jyan Chou
On 2023/8/25 22:35, Sergey Khimich wrote:
Implement SDHCI CQE support for DesignWare SDHCI.
For enabling CQE support just set 'supports-cqe' in your DevTree file
for appropriate mmc node.
Hi Sergey
Jyan had pushed a version to support it:
https://patchwork.kernel.org/project/linux-mmc/patch/20230616063731.17591-1-jyanchou@xxxxxxxxxxx/
And obviously there are some special limitations from IP vendor
you need to address such as 128MB DMA boundary.
Signed-off-by: Sergey Khimich <serghox@xxxxxxxxx>
---
drivers/mmc/host/Kconfig | 1 +
drivers/mmc/host/sdhci-of-dwcmshc.c | 154 +++++++++++++++++++++++++++-
2 files changed, 154 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 159a3e9490ae..c9fc790d7dba 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -233,6 +233,7 @@ config MMC_SDHCI_OF_DWCMSHC
depends on MMC_SDHCI_PLTFM
depends on OF
depends on COMMON_CLK
+ select MMC_CQHCI
help
This selects Synopsys DesignWare Cores Mobile Storage Controller
support.
diff --git a/drivers/mmc/host/sdhci-of-dwcmshc.c b/drivers/mmc/host/sdhci-of-dwcmshc.c
index e68cd87998c8..5ee8954a8f5a 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -19,6 +19,7 @@
#include <linux/sizes.h>
#include "sdhci-pltfm.h"
+#include "cqhci.h"
#define SDHCI_DWCMSHC_ARG2_STUFF GENMASK(31, 16)
@@ -35,6 +36,9 @@
#define DWCMSHC_ENHANCED_STROBE BIT(8)
#define DWCMSHC_EMMC_ATCTRL 0x40
+/* DWC IP vendor area 2 pointer */
+#define DWCMSHC_P_VENDOR_AREA2 0xea
+
/* Rockchip specific Registers */
#define DWCMSHC_EMMC_DLL_CTRL 0x800
#define DWCMSHC_EMMC_DLL_RXCLK 0x804
@@ -74,6 +78,10 @@
#define BOUNDARY_OK(addr, len) \
((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))
+#define DWCMCHC_SDHCI_CQE_TRNS_MODE (SDHCI_TRNS_MULTI | \
+ SDHCI_TRNS_BLK_CNT_EN | \
+ SDHCI_TRNS_DMA)
+
enum dwcmshc_rk_type {
DWCMSHC_RK3568,
DWCMSHC_RK3588,
@@ -89,7 +97,8 @@ struct rk35xx_priv {
struct dwcmshc_priv {
struct clk *bus_clk;
- int vendor_specific_area1; /* P_VENDOR_SPECIFIC_AREA reg */
+ int vendor_specific_area1; /* P_VENDOR_SPECIFIC_AREA1 reg */
+ int vendor_specific_area2; /* P_VENDOR_SPECIFIC_AREA2 reg */
void *priv; /* pointer to SoC private stuff */
};
@@ -209,6 +218,65 @@ static void dwcmshc_hs400_enhanced_strobe(struct mmc_host *mmc,
sdhci_writel(host, vendor, reg);
}
+static u32 dwcmshc_cqe_irq_handler(struct sdhci_host *host, u32 intmask)
+{
+ int cmd_error = 0;
+ int data_error = 0;
+
+ if (!sdhci_cqe_irq(host, intmask, &cmd_error, &data_error))
+ return intmask;
+
+ cqhci_irq(host->mmc, intmask, cmd_error, data_error);
+
+ return 0;
+}
+
+static void dwcmshc_sdhci_cqe_enable(struct mmc_host *mmc)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ u32 pstate;
+ u8 ctrl;
+ int count = 10;
+
+ /*
+ * CQE gets stuck if it sees Buffer Read Enable bit set, which can be
+ * the case after tuning, so ensure the buffer is drained.
+ */
+ pstate = sdhci_readl(host, SDHCI_PRESENT_STATE);
+ while (pstate & SDHCI_DATA_AVAILABLE) {
+ sdhci_readl(host, SDHCI_BUFFER);
+ pstate = sdhci_readl(host, SDHCI_PRESENT_STATE);
+ if (count-- == 0) {
+ dev_warn(mmc_dev(host->mmc),
+ "CQE may get stuck because the Buffer Read Enable bit is set\n");
+ break;
+ }
+ mdelay(1);
+ }
+
+ sdhci_writew(host, DWCMCHC_SDHCI_CQE_TRNS_MODE, SDHCI_TRANSFER_MODE);
+
+ sdhci_cqe_enable(mmc);
+
+ /*
+ * The "DesignWare Cores Mobile Storage Host Controller
+ * DWC_mshc / DWC_mshc_lite Databook" says:
+ * when Host Version 4 Enable" is 1 in Host Control 2 register,
+ * SDHCI_CTRL_ADMA32 bit means ADMA2 is selected.
+ * Selection of 32-bit/64-bit System Addressing:
+ * either 32-bit or 64-bit system addressing is selected by
+ * 64-bit Addressing bit in Host Control 2 register.
+ *
+ * On the other hand the "DesignWare Cores Mobile Storage Host
+ * Controller DWC_mshc / DWC_mshc_lite User Guide" says, that we have to
+ * set DMA_SEL to ADMA2 _only_ mode in the Host Control 2 register.
+ */
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+ ctrl &= ~SDHCI_CTRL_DMA_MASK;
+ ctrl |= SDHCI_CTRL_ADMA32;
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+}
+
static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -344,6 +412,7 @@ static const struct sdhci_ops sdhci_dwcmshc_ops = {
.get_max_clock = dwcmshc_get_max_clock,
.reset = sdhci_reset,
.adma_write_desc = dwcmshc_adma_write_desc,
+ .irq = dwcmshc_cqe_irq_handler,
};
static const struct sdhci_ops sdhci_dwcmshc_rk35xx_ops = {
@@ -378,6 +447,74 @@ static const struct sdhci_pltfm_data sdhci_dwcmshc_rk35xx_pdata = {
SDHCI_QUIRK2_CLOCK_DIV_ZERO_BROKEN,
};
+static void dwcmshc_cqhci_dumpregs(struct mmc_host *mmc)
+{
+ sdhci_dumpregs(mmc_priv(mmc));
+}
+
+static const struct cqhci_host_ops dwcmshc_cqhci_ops = {
+ .enable = dwcmshc_sdhci_cqe_enable,
+ .disable = sdhci_cqe_disable,
+ .dumpregs = dwcmshc_cqhci_dumpregs,
+};
+
+static void dwcmshc_cqhci_init(struct sdhci_host *host, struct platform_device *pdev)
+{
+ struct cqhci_host *cq_host;
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
+ bool dma64 = false;
+ u16 clk;
+ int err;
+
+ host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
+ cq_host = devm_kzalloc(&pdev->dev, sizeof(*cq_host), GFP_KERNEL);
+ if (!cq_host) {
+ dev_err(mmc_dev(host->mmc), "Unable to setup CQE: not enough memory\n");
+ return;
+ }
+
+ /*
+ * For dwcmshc host controller we have to enable internal clock
+ * before access to some registers from Vendor Specific Aria 2.
+ */
+ clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+ clk |= SDHCI_CLOCK_INT_EN;
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+ clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+ if (!(clk & SDHCI_CLOCK_INT_EN)) {
+ dev_err(mmc_dev(host->mmc), "Unable to setup CQE: internal clock enable error\n");
+ goto free_cq_host;
+ }
+
+ cq_host->mmio = host->ioaddr + priv->vendor_specific_area2;
+ cq_host->ops = &dwcmshc_cqhci_ops;
+
+ /* Enable using of 128-bit task descriptors */
+ dma64 = host->flags & SDHCI_USE_64_BIT_DMA;
+ if (dma64) {
+ dev_dbg(mmc_dev(host->mmc), "128-bit task descriptors\n");
+ cq_host->caps |= CQHCI_TASK_DESC_SZ_128;
+ }
+ err = cqhci_init(cq_host, host->mmc, dma64);
+ if (err) {
+ dev_err(mmc_dev(host->mmc), "Unable to setup CQE: error %d\n", err);
+ goto int_clok_disable;
+ }
+
+ dev_dbg(mmc_dev(host->mmc), "CQE init done\n");
+
+ return;
+
+int_clok_disable:
+ clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+ clk &= ~SDHCI_CLOCK_INT_EN;
+ sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+free_cq_host:
+ devm_kfree(&pdev->dev, cq_host);
+}
+
static int dwcmshc_rk35xx_init(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv)
{
int err;
@@ -471,6 +608,7 @@ static int dwcmshc_probe(struct platform_device *pdev)
const struct sdhci_pltfm_data *pltfm_data;
int err;
u32 extra;
+ u32 caps;
pltfm_data = device_get_match_data(&pdev->dev);
if (!pltfm_data) {
@@ -518,6 +656,8 @@ static int dwcmshc_probe(struct platform_device *pdev)
priv->vendor_specific_area1 =
sdhci_readl(host, DWCMSHC_P_VENDOR_AREA1) & DWCMSHC_AREA1_MASK;
+ priv->vendor_specific_area2 =
+ sdhci_readw(host, DWCMSHC_P_VENDOR_AREA2);
host->mmc_host_ops.request = dwcmshc_request;
host->mmc_host_ops.hs400_enhanced_strobe = dwcmshc_hs400_enhanced_strobe;
@@ -546,12 +686,24 @@ static int dwcmshc_probe(struct platform_device *pdev)
sdhci_enable_v4_mode(host);
#endif
+ caps = sdhci_readl(host, SDHCI_CAPABILITIES);
+ if (caps & SDHCI_CAN_64BIT_V4)
+ sdhci_enable_v4_mode(host);
+
host->mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
err = sdhci_setup_host(host);
if (err)
goto err_clk;
+ /* Setup Command Queue Engine if enabled */
+ if (device_property_read_bool(&pdev->dev, "supports-cqe")) {
+ if (caps & SDHCI_CAN_64BIT_V4)
+ dwcmshc_cqhci_init(host, pdev);
+ else
+ dev_warn(dev, "Cannot enable CQE without V4 mode support\n");
+ }
+
if (rk_priv)
dwcmshc_rk35xx_postinit(host, priv);