Add hardware tuning function instead of software tuning because O2/Bayhub
SD host controller support hardware tuning.
Changes: Add many functions to execute hardware tuning for eMMC 1.8V HS200
mode, the hardware tuning command and procedure is based on O2/Bayhub
hardware tuning spec.
Signed-off-by: ernest.zhang <ernest.zhang@xxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-pci-o2micro.c | 193 +++++++++++++++++++++++++++++++++++
drivers/mmc/host/sdhci.c | 5 +-
2 files changed, 197 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-pci-o2micro.c b/drivers/mmc/host/sdhci-pci-o2micro.c
index d465751..a918984 100644
--- a/drivers/mmc/host/sdhci-pci-o2micro.c
+++ b/drivers/mmc/host/sdhci-pci-o2micro.c
@@ -17,6 +17,9 @@
*/
#include <linux/pci.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
+#include <linux/delay.h>
#include "sdhci.h"
#include "sdhci-pci.h"
@@ -55,6 +58,194 @@
#define O2_SD_VENDOR_SETTING 0x110
#define O2_SD_VENDOR_SETTING2 0x1C8
+#define O2_SD_HW_TUNING_DISABLE BIT(4)
+
+static void sdhci_o2_start_tuning(struct sdhci_host *host)
+{
+ u16 ctrl;
+
+ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ ctrl |= SDHCI_CTRL_EXEC_TUNING;
+ sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+
+ /*
+ * As per the Host Controller spec v3.00, tuning command
+ * generates Buffer Read Ready interrupt, so enable that.
+ *
+ * Note: The spec clearly says that when tuning sequence
+ * is being performed, the controller does not generate
+ * interrupts other than Buffer Read Ready interrupt. But
+ * to make sure we don't hit a controller bug, we _only_
+ * enable Buffer Read Ready interrupt here.
+ */
+ sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_INT_ENABLE);
+ sdhci_writel(host, SDHCI_INT_DATA_AVAIL, SDHCI_SIGNAL_ENABLE);
+}
+
+static void sdhci_o2_end_tuning(struct sdhci_host *host)
+{
+ sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
+ sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
+}
+
+static inline bool sdhci_data_line_cmd(struct mmc_command *cmd)
+{
+ return cmd->data || cmd->flags & MMC_RSP_BUSY;
+}
+
+static void sdhci_del_timer(struct sdhci_host *host, struct mmc_request *mrq)
+{
+ if (sdhci_data_line_cmd(mrq->cmd))
+ del_timer(&host->data_timer);
+ else
+ del_timer(&host->timer);
+}
+
+static void sdhci_o2_set_tuning_mode(struct sdhci_host *host)
+{
+ u16 reg;
+
+ /* enable hardware tuning */
+ reg = sdhci_readw(host, O2_SD_VENDOR_SETTING);
+ reg &= ~O2_SD_HW_TUNING_DISABLE;
+ sdhci_writew(host, reg, O2_SD_VENDOR_SETTING);
+}
+
+
+static int sdhci_o2_send_tuning(struct sdhci_host *host, u32 opcode)
+{
+ struct mmc_command cmd = { };
+ struct mmc_data data = { };
+ struct scatterlist sg;
+ struct mmc_request mrq = { };
+ unsigned long flags;
+ u32 b = host->sdma_boundary;
+ int size = 64;
+ u8 *data_buf = kzalloc(size, GFP_KERNEL);
+
+ if (!data_buf)
+ return -ENOMEM;
+
+ cmd.opcode = opcode;
+ cmd.flags = MMC_RSP_PRESENT | MMC_RSP_OPCODE | MMC_RSP_CRC;
+ cmd.mrq = &mrq;
+ cmd.data = NULL;
+ mrq.cmd = &cmd;
+ mrq.data = &data;
+ data.blksz = size;
+ data.blocks = 1;
+ data.flags = MMC_DATA_READ;
+
+ data.timeout_ns = 50 * NSEC_PER_MSEC;
+
+ data.sg = &sg;
+ data.sg_len = 1;
+ sg_init_one(&sg, data_buf, size);
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ sdhci_writew(host, SDHCI_MAKE_BLKSZ(b, 64), SDHCI_BLOCK_SIZE);
+
+ /*
+ * The tuning block is sent by the card to the host controller.
+ * So we set the TRNS_READ bit in the Transfer Mode register.
+ * This also takes care of setting DMA Enable and Multi Block
+ * Select in the same register to 0.
+ */
+ sdhci_writew(host, SDHCI_TRNS_READ, SDHCI_TRANSFER_MODE);
+
+ sdhci_send_command(host, &cmd);
+
+ host->cmd = NULL;
+
+ sdhci_del_timer(host, &mrq);
+
+ host->tuning_done = 0;
+
+ mmiowb();
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ /* Wait for Buffer Read Ready interrupt */
+ wait_event_timeout(host->buf_ready_int, (host->tuning_done == 1),
+ msecs_to_jiffies(50));
+ kfree(data_buf);
+ return 0;
+}
+
+static void sdhci_o2_reset_tuning(struct sdhci_host *host)
+{
+ u16 ctrl;
+
+ ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ ctrl &= ~SDHCI_CTRL_TUNED_CLK;
+ ctrl &= ~SDHCI_CTRL_EXEC_TUNING;
+ sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+}
+
+static void __sdhci_o2_execute_tuning(struct sdhci_host *host, u32 opcode)
+{
+ int i;
+
+ sdhci_o2_send_tuning(host, MMC_SEND_TUNING_BLOCK_HS200);
+
+ for (i = 0; i < 150; i++) {
+ u16 ctrl = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+
+ if (!(ctrl & SDHCI_CTRL_EXEC_TUNING)) {
+ if (ctrl & SDHCI_CTRL_TUNED_CLK) {
+ host->tuning_done = true;
+ return;
+ }
+ pr_warn("%s: HW tuning failed !\n",
+ mmc_hostname(host->mmc));
+ break;
+ }
+
+ mdelay(1);
+ }
+
+ pr_info("%s: Tuning failed, falling back to fixed sampling clock\n",
+ mmc_hostname(host->mmc));
+ sdhci_o2_reset_tuning(host);
+}
+
+static int sdhci_o2_execute_tuning(struct mmc_host *mmc, u32 opcode)
+{
+ struct sdhci_host *host = mmc_priv(mmc);
+ int current_bus_width = 0;
+
+ /*
+ * This handler only implements the eMMC tuning that is specific to
+ * this controller. Fall back to the standard method for other TIMING.
+ */
+ if (host->timing != MMC_TIMING_MMC_HS200)
+ return sdhci_execute_tuning(mmc, opcode);
+
+ if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200))
+ return -EINVAL;
+
+ /*
+ * o2 sdhci host didn't support 8bit emmc tuning
+ */
+ if (mmc->ios.bus_width == MMC_BUS_WIDTH_8) {
+ current_bus_width = mmc->ios.bus_width;
+ sdhci_set_bus_width(host, MMC_BUS_WIDTH_4);
+ }
+
+ sdhci_o2_set_tuning_mode(host);
+
+ sdhci_o2_start_tuning(host);
+
+ __sdhci_o2_execute_tuning(host, opcode);
+
+ sdhci_o2_end_tuning(host);
+
+ if (current_bus_width == MMC_BUS_WIDTH_8)
+ sdhci_set_bus_width(host, current_bus_width);
+
+ host->flags &= ~SDHCI_HS400_TUNING;
+ return 0;
+}
static void o2_pci_set_baseclk(struct sdhci_pci_chip *chip, u32 value)
{
@@ -215,6 +406,8 @@ int sdhci_pci_o2_probe_slot(struct sdhci_pci_slot *slot)
}
}
+ host->mmc_host_ops.execute_tuning = sdhci_o2_execute_tuning;
+
if (chip->pdev->device != PCI_DEVICE_ID_O2_FUJIN2)
break;
/* set dll watch dog timer */
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 2ededa7..3bf6117 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -955,7 +955,10 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
if (data == NULL) {
if (host->quirks2 &
SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD) {
- sdhci_writew(host, 0x0, SDHCI_TRANSFER_MODE);
+ /* must not clear SDHCI_TRANSFER_MODE when tuning */
+ if (cmd->opcode != MMC_SEND_TUNING_BLOCK_HS200) {
+ sdhci_writew(host, 0x0, SDHCI_TRANSFER_MODE);
+ }
} else {
/* clear Auto CMD settings for no data CMDs */
mode = sdhci_readw(host, SDHCI_TRANSFER_MODE);
--
2.7.4
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