[PATCH v7 2/2] mmc: sdhci-of-dwcmshc: Implement SDHCI CQE support

From: Sergey Khimich
Date: Tue Mar 19 2024 - 08:00:08 EST


From: Sergey Khimich <serghox@xxxxxxxxx>

For enabling CQE support just set 'supports-cqe' in your DevTree file
for appropriate mmc node.

Signed-off-by: Sergey Khimich <serghox@xxxxxxxxx>
---
drivers/mmc/host/Kconfig | 1 +
drivers/mmc/host/sdhci-of-dwcmshc.c | 191 +++++++++++++++++++++++++++-
2 files changed, 190 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 81f2c4e05287..554dbf7f2fa4 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 a1f57af6acfb..8d6cfb648096 100644
--- a/drivers/mmc/host/sdhci-of-dwcmshc.c
+++ b/drivers/mmc/host/sdhci-of-dwcmshc.c
@@ -21,6 +21,7 @@
#include <linux/sizes.h>

#include "sdhci-pltfm.h"
+#include "cqhci.h"

#define SDHCI_DWCMSHC_ARG2_STUFF GENMASK(31, 16)

@@ -52,6 +53,9 @@
#define AT_CTRL_SWIN_TH_VAL_MASK GENMASK(31, 24) /* bits [31:24] */
#define AT_CTRL_SWIN_TH_VAL 0x9 /* sampling window threshold */

+/* 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
@@ -167,6 +171,10 @@
#define BOUNDARY_OK(addr, len) \
((addr | (SZ_128M - 1)) == ((addr + len - 1) | (SZ_128M - 1)))

+#define DWCMSHC_SDHCI_CQE_TRNS_MODE (SDHCI_TRNS_MULTI | \
+ SDHCI_TRNS_BLK_CNT_EN | \
+ SDHCI_TRNS_DMA)
+
enum dwcmshc_rk_type {
DWCMSHC_RK3568,
DWCMSHC_RK3588,
@@ -182,7 +190,9 @@ 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 */
u16 delay_line;
u16 flags;
@@ -441,6 +451,90 @@ static void dwcmshc_hs400_enhanced_strobe(struct mmc_host *mmc,
sdhci_writel(host, vendor, reg);
}

+static int dwcmshc_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+ int err = sdhci_execute_tuning(mmc, opcode);
+ struct sdhci_host *host = mmc_priv(mmc);
+
+ if (err)
+ return err;
+
+ /*
+ * Tuning can leave the IP in an active state (Buffer Read Enable bit
+ * set) which prevents the entry to low power states (i.e. S0i3). Data
+ * reset will clear it.
+ */
+ sdhci_reset(host, SDHCI_RESET_DATA);
+
+ return 0;
+}
+
+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);
+ u8 ctrl;
+
+ sdhci_writew(host, DWCMSHC_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_set_tran_desc(struct cqhci_host *cq_host, u8 **desc,
+ dma_addr_t addr, int len, bool end, bool dma64)
+{
+ int tmplen, offset;
+
+ if (likely(!len || BOUNDARY_OK(addr, len))) {
+ cqhci_set_tran_desc(*desc, addr, len, end, dma64);
+ return;
+ }
+
+ offset = addr & (SZ_128M - 1);
+ tmplen = SZ_128M - offset;
+ cqhci_set_tran_desc(*desc, addr, tmplen, false, dma64);
+
+ addr += tmplen;
+ len -= tmplen;
+ *desc += cq_host->trans_desc_len;
+ cqhci_set_tran_desc(*desc, addr, len, end, dma64);
+}
+
+static void dwcmshc_cqhci_dumpregs(struct mmc_host *mmc)
+{
+ sdhci_dumpregs(mmc_priv(mmc));
+}
+
static void dwcmshc_rk3568_set_clock(struct sdhci_host *host, unsigned int clock)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -649,6 +743,7 @@ 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 = {
@@ -700,6 +795,73 @@ static const struct sdhci_pltfm_data sdhci_dwcmshc_th1520_pdata = {
.quirks2 = SDHCI_QUIRK2_PRESET_VALUE_BROKEN,
};

+static const struct cqhci_host_ops dwcmshc_cqhci_ops = {
+ .enable = dwcmshc_sdhci_cqe_enable,
+ .disable = sdhci_cqe_disable,
+ .dumpregs = dwcmshc_cqhci_dumpregs,
+ .set_tran_desc = dwcmshc_set_tran_desc,
+};
+
+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");
+ goto dsbl_cqe_caps;
+ }
+
+ /*
+ * For dwcmshc host controller we have to enable internal clock
+ * before access to some registers from Vendor Specific Area 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_clock_disable;
+ }
+
+ dev_dbg(mmc_dev(host->mmc), "CQE init done\n");
+
+ return;
+
+int_clock_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);
+
+dsbl_cqe_caps:
+ host->mmc->caps2 &= ~(MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD);
+}
+
static int dwcmshc_rk35xx_init(struct sdhci_host *host, struct dwcmshc_priv *dwc_priv)
{
int err;
@@ -796,7 +958,7 @@ static int dwcmshc_probe(struct platform_device *pdev)
struct rk35xx_priv *rk_priv = NULL;
const struct sdhci_pltfm_data *pltfm_data;
int err;
- u32 extra;
+ u32 extra, caps;

pltfm_data = device_get_match_data(&pdev->dev);
if (!pltfm_data) {
@@ -847,6 +1009,7 @@ static int dwcmshc_probe(struct platform_device *pdev)

host->mmc_host_ops.request = dwcmshc_request;
host->mmc_host_ops.hs400_enhanced_strobe = dwcmshc_hs400_enhanced_strobe;
+ host->mmc_host_ops.execute_tuning = dwcmshc_execute_tuning;

if (pltfm_data == &sdhci_dwcmshc_rk35xx_pdata) {
rk_priv = devm_kzalloc(&pdev->dev, sizeof(struct rk35xx_priv), GFP_KERNEL);
@@ -896,6 +1059,10 @@ 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;

pm_runtime_get_noresume(dev);
@@ -906,6 +1073,14 @@ static int dwcmshc_probe(struct platform_device *pdev)
if (err)
goto err_rpm;

+ /* Setup Command Queue Engine if enabled */
+ if (device_property_read_bool(&pdev->dev, "supports-cqe")) {
+ priv->vendor_specific_area2 =
+ sdhci_readw(host, DWCMSHC_P_VENDOR_AREA2);
+
+ dwcmshc_cqhci_init(host, pdev);
+ }
+
if (rk_priv)
dwcmshc_rk35xx_postinit(host, priv);

@@ -961,6 +1136,12 @@ static int dwcmshc_suspend(struct device *dev)

pm_runtime_resume(dev);

+ if (host->mmc->caps2 & MMC_CAP2_CQE) {
+ ret = cqhci_suspend(host->mmc);
+ if (ret)
+ return ret;
+ }
+
ret = sdhci_suspend_host(host);
if (ret)
return ret;
@@ -1005,6 +1186,12 @@ static int dwcmshc_resume(struct device *dev)
if (ret)
goto disable_rockchip_clks;

+ if (host->mmc->caps2 & MMC_CAP2_CQE) {
+ ret = cqhci_resume(host->mmc);
+ if (ret)
+ goto disable_rockchip_clks;
+ }
+
return 0;

disable_rockchip_clks:
--
2.30.2