[PATCH] mmc: core: Add host specific tuning support for SD HS mode
From: Wenchao Chen
Date: Wed Aug 09 2023 - 01:30:26 EST
Added .prepare_hs_tuning and .execute_hs_tuning host
callbacks to support host-specific tuning for SD high
speed mode.
Signed-off-by: Wenchao Chen <wenchao.chen@xxxxxxxxxx>
---
drivers/mmc/core/sd.c | 12 ++++
drivers/mmc/host/sdhci-sprd.c | 124 ++++++++++++++++++++++++++++++++++
include/linux/mmc/host.h | 6 ++
3 files changed, 142 insertions(+)
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 246ce027ae0a..ac2da8f2fbce 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1518,6 +1518,12 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
*/
mmc_set_clock(host, mmc_sd_get_max_clock(card));
+ if (host->ops->prepare_hs_tuning) {
+ err = host->ops->prepare_hs_tuning(host, card);
+ if (err)
+ goto free_card;
+ }
+
/*
* Switch to wider bus (if supported).
*/
@@ -1529,6 +1535,12 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
}
+
+ if (host->ops->execute_hs_tuning) {
+ err = host->ops->execute_hs_tuning(host, card);
+ if (err)
+ goto free_card;
+ }
}
cont:
if (!oldcard) {
diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c
index 7f4ee2e12735..5f365dcbb9c7 100644
--- a/drivers/mmc/host/sdhci-sprd.c
+++ b/drivers/mmc/host/sdhci-sprd.c
@@ -9,6 +9,7 @@
#include <linux/dma-mapping.h>
#include <linux/highmem.h>
#include <linux/iopoll.h>
+#include <linux/mmc/mmc.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
@@ -22,6 +23,9 @@
#include "sdhci-pltfm.h"
#include "mmc_hsq.h"
+#include "../core/mmc_ops.h"
+#include "../core/sd_ops.h"
+
/* SDHCI_ARGUMENT2 register high 16bit */
#define SDHCI_SPRD_ARG2_STUFF GENMASK(31, 16)
@@ -73,6 +77,11 @@
#define SDHCI_SPRD_CLK_DEF_RATE 26000000
#define SDHCI_SPRD_PHY_DLL_CLK 52000000
+#define SDHCI_SPRD_MAX_PHASE 0xff
+#define SDHCI_SPRD_CMD_DLY_MASK GENMASK(15, 8)
+#define SDHCI_SPRD_POSRD_DLY_MASK GENMASK(23, 16)
+#define SDHCI_SPRD_CPST_EN GENMASK(27, 24)
+
struct sdhci_sprd_host {
u32 version;
struct clk *clk_sdio;
@@ -86,6 +95,11 @@ struct sdhci_sprd_host {
u32 phy_delay[MMC_TIMING_MMC_HS400 + 2];
};
+enum sdhci_sprd_tuning_type {
+ SDHCI_SPRD_TUNING_SD_HS_CMD,
+ SDHCI_SPRD_TUNING_SD_HS_DATA,
+};
+
struct sdhci_sprd_phy_cfg {
const char *property;
u8 timing;
@@ -533,6 +547,111 @@ static void sdhci_sprd_hs400_enhanced_strobe(struct mmc_host *mmc,
SDHCI_SPRD_REG_32_DLL_DLY);
}
+static int mmc_send_tuning_cmd(struct mmc_card *card)
+{
+ return mmc_send_status(card, NULL);
+}
+
+static int mmc_send_tuning_data(struct mmc_card *card)
+{
+ u8 status[64];
+
+ return mmc_sd_switch(card, 0, 0, 0, status);
+}
+
+static int sdhci_sprd_tuning(struct mmc_host *mmc, struct mmc_card *card,
+ enum sdhci_sprd_tuning_type type)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ struct sdhci_sprd_host *sprd_host = TO_SPRD_HOST(host);
+ u32 *p = sprd_host->phy_delay;
+ int err = 0;
+ int i;
+ bool value;
+ int final_phase;
+ u32 dll_cfg, dll_dly;
+ int range_end = SDHCI_SPRD_MAX_PHASE;
+ int len = 0;
+ int count = 0;
+
+ sdhci_reset(host, SDHCI_RESET_CMD | SDHCI_RESET_DATA);
+
+ dll_cfg = sdhci_readl(host, SDHCI_SPRD_REG_32_DLL_CFG);
+ dll_cfg &= ~SDHCI_SPRD_CPST_EN;
+ sdhci_writel(host, dll_cfg, SDHCI_SPRD_REG_32_DLL_CFG);
+
+ dll_dly = p[mmc->ios.timing];
+
+ for (i = 0; i <= SDHCI_SPRD_MAX_PHASE; i++) {
+ if (type == SDHCI_SPRD_TUNING_SD_HS_CMD) {
+ dll_dly &= ~SDHCI_SPRD_CMD_DLY_MASK;
+ dll_dly |= ((i << 8) & SDHCI_SPRD_CMD_DLY_MASK);
+ } else {
+ dll_dly &= ~SDHCI_SPRD_POSRD_DLY_MASK;
+ dll_dly |= ((i << 16) & SDHCI_SPRD_POSRD_DLY_MASK);
+ }
+
+ sdhci_writel(host, dll_dly, SDHCI_SPRD_REG_32_DLL_DLY);
+
+ if (type == SDHCI_SPRD_TUNING_SD_HS_CMD)
+ value = !mmc_send_tuning_cmd(card);
+ else
+ value = !mmc_send_tuning_data(card);
+
+ if (value) {
+ dev_dbg(mmc_dev(host->mmc), "tuning ok: %d\n", i);
+ count++;
+ } else {
+ dev_dbg(mmc_dev(host->mmc), "tuning fail: %d\n", i);
+ if (len < count) {
+ len = count;
+ range_end = i - 1;
+ count = 0;
+ }
+ }
+ }
+
+ if (!count) {
+ final_phase = 0;
+ dev_err(mmc_dev(host->mmc), "all tuning phase fail!\n");
+ err = -EIO;
+ goto out;
+ }
+
+ if (count > len) {
+ len = count;
+ range_end = i - 1;
+ }
+
+ final_phase = range_end - (len - 1) / 2;
+
+ if (type == SDHCI_SPRD_TUNING_SD_HS_CMD) {
+ p[mmc->ios.timing] &= ~SDHCI_SPRD_CMD_DLY_MASK;
+ p[mmc->ios.timing] |= ((final_phase << 8) & SDHCI_SPRD_CMD_DLY_MASK);
+ } else {
+ p[mmc->ios.timing] &= ~(SDHCI_SPRD_POSRD_DLY_MASK);
+ p[mmc->ios.timing] |= ((final_phase << 16) & SDHCI_SPRD_POSRD_DLY_MASK);
+ }
+
+ dev_info(mmc_dev(host->mmc), "the best step %d, phase 0x%02x, delay value 0x%08x\n",
+ final_phase, final_phase, p[mmc->ios.timing]);
+
+out:
+ sdhci_writel(host, p[mmc->ios.timing], SDHCI_SPRD_REG_32_DLL_DLY);
+
+ return err;
+}
+
+static int sdhci_sprd_prepare_hs_cmd_tuning(struct mmc_host *mmc, struct mmc_card *card)
+{
+ return sdhci_sprd_tuning(mmc, card, SDHCI_SPRD_TUNING_SD_HS_CMD);
+}
+
+static int sdhci_sprd_execute_hs_data_tuning(struct mmc_host *mmc, struct mmc_card *card)
+{
+ return sdhci_sprd_tuning(mmc, card, SDHCI_SPRD_TUNING_SD_HS_DATA);
+}
+
static void sdhci_sprd_phy_param_parse(struct sdhci_sprd_host *sprd_host,
struct device_node *np)
{
@@ -577,6 +696,11 @@ static int sdhci_sprd_probe(struct platform_device *pdev)
host->mmc_host_ops.request = sdhci_sprd_request;
host->mmc_host_ops.hs400_enhanced_strobe =
sdhci_sprd_hs400_enhanced_strobe;
+ host->mmc_host_ops.prepare_hs_tuning =
+ sdhci_sprd_prepare_hs_cmd_tuning;
+ host->mmc_host_ops.execute_hs_tuning =
+ sdhci_sprd_execute_hs_data_tuning;
+
/*
* We can not use the standard ops to change and detect the voltage
* signal for Spreadtrum SD host controller, since our voltage regulator
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 461d1543893b..13cf894b9e3c 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -184,6 +184,12 @@ struct mmc_host_ops {
/* Execute HS400 tuning depending host driver */
int (*execute_hs400_tuning)(struct mmc_host *host, struct mmc_card *card);
+ /* Prepare HS tuning depending host driver */
+ int (*prepare_hs_tuning)(struct mmc_host *host, struct mmc_card *card);
+
+ /* Execute HS tuning depending host driver */
+ int (*execute_hs_tuning)(struct mmc_host *host, struct mmc_card *card);
+
/* Prepare switch to DDR during the HS400 init sequence */
int (*hs400_prepare_ddr)(struct mmc_host *host);
--
2.17.1