Bluetooth: mt7921s: support bluetooth reset mechanism

Implement .cmd_timeout to reset the MT7921s device via a dedicated GPIO
pin when the firmware hang or the command has no response.

Co-developed-by: Mark Chen <mark-yw.chen@mediatek.com>
Signed-off-by: Mark Chen <mark-yw.chen@mediatek.com>
Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Chih-Ying Chiang <chih-yin.chiang@mediatek.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

diff --git a/drivers/bluetooth/btmtk.h b/drivers/bluetooth/btmtk.h
index fb76d97..8960a5f 100644 (file)
--- a/drivers/bluetooth/btmtk.h
+++ b/drivers/bluetooth/btmtk.h
@@ -10,9 +10,15 @@
 #define BTMTK_WMT_REG_WRITE 0x1
 #define BTMTK_WMT_REG_READ 0x2
 
+#define MT7921_BTSYS_RST 0x70002610
+#define MT7921_BTSYS_RST_WITH_GPIO BIT(7)
+
 #define MT7921_PINMUX_0 0x70005050
 #define MT7921_PINMUX_1 0x70005054
 
+#define MT7921_DLSTATUS 0x7c053c10
+#define BT_DL_STATE BIT(1)
+
 enum {
        BTMTK_WMT_PATCH_DWNLD = 0x1,
        BTMTK_WMT_TEST = 0x2,

diff --git a/drivers/bluetooth/btmtksdio.c b/drivers/bluetooth/btmtksdio.c
index 8be763a..8e200e8 100644 (file)
--- a/drivers/bluetooth/btmtksdio.c
+++ b/drivers/bluetooth/btmtksdio.c
@@ -12,10 +12,12 @@
 
 #include <asm/unaligned.h>
 #include <linux/atomic.h>
+#include <linux/gpio/consumer.h>
 #include <linux/init.h>
 #include <linux/iopoll.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/of.h>
 #include <linux/pm_runtime.h>
 #include <linux/skbuff.h>
 
@@ -83,6 +85,7 @@ MODULE_DEVICE_TABLE(sdio, btmtksdio_table);
 
 #define MTK_REG_CHCR           0xc
 #define C_INT_CLR_CTRL         BIT(1)
+#define BT_RST_DONE            BIT(8)
 
 /* CHISR have the same bits field definition with CHIER */
 #define MTK_REG_CHISR          0x10
@@ -114,6 +117,7 @@ MODULE_DEVICE_TABLE(sdio, btmtksdio_table);
 #define BTMTKSDIO_HW_TX_READY          2
 #define BTMTKSDIO_FUNC_ENABLED         3
 #define BTMTKSDIO_PATCH_ENABLED                4
+#define BTMTKSDIO_HW_RESET_ACTIVE      5
 
 struct mtkbtsdio_hdr {
        __le16  len;
@@ -133,6 +137,8 @@ struct btmtksdio_dev {
        struct sk_buff *evt_skb;
 
        const struct btmtksdio_data *data;
+
+       struct gpio_desc *reset;
 };
 
 static int mtk_hci_wmt_sync(struct hci_dev *hdev,
@@ -297,6 +303,11 @@ static u32 btmtksdio_drv_own_query_79xx(struct btmtksdio_dev *bdev)
        return sdio_readl(bdev->func, MTK_REG_PD2HRM0R, NULL);
 }
 
+static u32 btmtksdio_chcr_query(struct btmtksdio_dev *bdev)
+{
+       return sdio_readl(bdev->func, MTK_REG_CHCR, NULL);
+}
+
 static int btmtksdio_fw_pmctrl(struct btmtksdio_dev *bdev)
 {
        u32 status;
@@ -967,6 +978,28 @@ static int btmtksdio_sco_setting(struct hci_dev *hdev)
        return btmtksdio_mtk_reg_write(hdev, MT7921_PINMUX_1, val, ~0);
 }
 
+static int btmtksdio_reset_setting(struct hci_dev *hdev)
+{
+       int err;
+       u32 val;
+
+       err = btmtksdio_mtk_reg_read(hdev, MT7921_PINMUX_1, &val);
+       if (err < 0)
+               return err;
+
+       val |= 0x20; /* set the pin (bit field 11:8) work as GPIO mode */
+       err = btmtksdio_mtk_reg_write(hdev, MT7921_PINMUX_1, val, ~0);
+       if (err < 0)
+               return err;
+
+       err = btmtksdio_mtk_reg_read(hdev, MT7921_BTSYS_RST, &val);
+       if (err < 0)
+               return err;
+
+       val |= MT7921_BTSYS_RST_WITH_GPIO;
+       return btmtksdio_mtk_reg_write(hdev, MT7921_BTSYS_RST, val, ~0);
+}
+
 static int btmtksdio_setup(struct hci_dev *hdev)
 {
        struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);
@@ -974,13 +1007,32 @@ static int btmtksdio_setup(struct hci_dev *hdev)
        unsigned long long duration;
        char fwname[64];
        int err, dev_id;
-       u32 fw_version = 0;
+       u32 fw_version = 0, val;
 
        calltime = ktime_get();
        set_bit(BTMTKSDIO_HW_TX_READY, &bdev->tx_state);
 
        switch (bdev->data->chipid) {
        case 0x7921:
+               if (test_bit(BTMTKSDIO_HW_RESET_ACTIVE, &bdev->tx_state)) {
+                       err = btmtksdio_mtk_reg_read(hdev, MT7921_DLSTATUS,
+                                                    &val);
+                       if (err < 0)
+                               return err;
+
+                       val &= ~BT_DL_STATE;
+                       err = btmtksdio_mtk_reg_write(hdev, MT7921_DLSTATUS,
+                                                     val, ~0);
+                       if (err < 0)
+                               return err;
+
+                       btmtksdio_fw_pmctrl(bdev);
+                       msleep(20);
+                       btmtksdio_drv_pmctrl(bdev);
+
+                       clear_bit(BTMTKSDIO_HW_RESET_ACTIVE, &bdev->tx_state);
+               }
+
                err = btmtksdio_mtk_reg_read(hdev, 0x70010200, &dev_id);
                if (err < 0) {
                        bt_dev_err(hdev, "Failed to get device id (%d)", err);
@@ -1015,6 +1067,16 @@ static int btmtksdio_setup(struct hci_dev *hdev)
                        return err;
                }
 
+               /* Enable GPIO reset mechanism */
+               if (bdev->reset) {
+                       err = btmtksdio_reset_setting(hdev);
+                       if (err < 0) {
+                               bt_dev_err(hdev, "Failed to enable Reset setting (%d)", err);
+                               devm_gpiod_put(bdev->dev, bdev->reset);
+                               bdev->reset = NULL;
+                       }
+               }
+
                break;
        case 0x7663:
        case 0x7668:
@@ -1111,6 +1173,47 @@ static int btmtksdio_send_frame(struct hci_dev *hdev, struct sk_buff *skb)
        return 0;
 }
 
+static void btmtksdio_cmd_timeout(struct hci_dev *hdev)
+{
+       struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);
+       u32 status;
+       int err;
+
+       if (!bdev->reset || bdev->data->chipid != 0x7921)
+               return;
+
+       pm_runtime_get_sync(bdev->dev);
+
+       if (test_and_set_bit(BTMTKSDIO_HW_RESET_ACTIVE, &bdev->tx_state))
+               return;
+
+       sdio_claim_host(bdev->func);
+
+       sdio_writel(bdev->func, C_INT_EN_CLR, MTK_REG_CHLPCR, NULL);
+       skb_queue_purge(&bdev->txq);
+       cancel_work_sync(&bdev->txrx_work);
+
+       gpiod_set_value_cansleep(bdev->reset, 1);
+       msleep(100);
+       gpiod_set_value_cansleep(bdev->reset, 0);
+
+       err = readx_poll_timeout(btmtksdio_chcr_query, bdev, status,
+                                status & BT_RST_DONE, 100000, 2000000);
+       if (err < 0) {
+               bt_dev_err(hdev, "Failed to reset (%d)", err);
+               goto err;
+       }
+
+       clear_bit(BTMTKSDIO_PATCH_ENABLED, &bdev->tx_state);
+err:
+       sdio_release_host(bdev->func);
+
+       pm_runtime_put_noidle(bdev->dev);
+       pm_runtime_disable(bdev->dev);
+
+       hci_reset_dev(hdev);
+}
+
 static bool btmtksdio_sdio_wakeup(struct hci_dev *hdev)
 {
        struct btmtksdio_dev *bdev = hci_get_drvdata(hdev);
@@ -1172,6 +1275,7 @@ static int btmtksdio_probe(struct sdio_func *func,
 
        hdev->open     = btmtksdio_open;
        hdev->close    = btmtksdio_close;
+       hdev->cmd_timeout = btmtksdio_cmd_timeout;
        hdev->flush    = btmtksdio_flush;
        hdev->setup    = btmtksdio_setup;
        hdev->shutdown = btmtksdio_shutdown;
@@ -1216,6 +1320,13 @@ static int btmtksdio_probe(struct sdio_func *func,
        if (err)
                bt_dev_err(hdev, "failed to initialize device wakeup");
 
+       bdev->dev->of_node = of_find_compatible_node(NULL, NULL,
+                                                    "mediatek,mt7921s-bluetooth");
+       bdev->reset = devm_gpiod_get_optional(bdev->dev, "reset",
+                                             GPIOD_OUT_LOW);
+       if (IS_ERR(bdev->reset))
+               err = PTR_ERR(bdev->reset);
+
        return err;
 }