From: Chin-Yen Lee <[email protected]>
Sometimes driver can't use kernel API pci_read/write_config_byte
to access the PCI config space of above address 0x100 due to
the negotiated PCI setting. 8852AE/8852BE/8851BE provide another
way called DBI function, which belongs to WiFi mac and could
access all PCI config space for this case.
Link: https://lore.kernel.org/linux-wireless/[email protected]/T/#t
Signed-off-by: Chin-Yen Lee <[email protected]>
Signed-off-by: Ping-Ke Shih <[email protected]>
---
drivers/net/wireless/realtek/rtw89/pci.c | 69 +++++++++++++++++++++++-
drivers/net/wireless/realtek/rtw89/pci.h | 1 +
2 files changed, 68 insertions(+), 2 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw89/pci.c b/drivers/net/wireless/realtek/rtw89/pci.c
index 769f1ce62ebc..9943ed856248 100644
--- a/drivers/net/wireless/realtek/rtw89/pci.c
+++ b/drivers/net/wireless/realtek/rtw89/pci.c
@@ -1907,22 +1907,87 @@ static int rtw89_write16_mdio_clr(struct rtw89_dev *rtwdev, u8 addr, u16 mask, u
return 0;
}
+static int rtw89_dbi_write8(struct rtw89_dev *rtwdev, u16 addr, u8 data)
+{
+ u16 addr_2lsb = addr & B_AX_DBI_2LSB;
+ u16 write_addr;
+ u8 flag;
+ int ret;
+
+ write_addr = addr & B_AX_DBI_ADDR_MSK;
+ write_addr |= u16_encode_bits(BIT(addr_2lsb), B_AX_DBI_WREN_MSK);
+ rtw89_write8(rtwdev, R_AX_DBI_WDATA + addr_2lsb, data);
+ rtw89_write16(rtwdev, R_AX_DBI_FLAG, write_addr);
+ rtw89_write8(rtwdev, R_AX_DBI_FLAG + 2, B_AX_DBI_WFLAG >> 16);
+
+ ret = read_poll_timeout_atomic(rtw89_read8, flag, !flag, 10,
+ 10 * RTW89_PCI_WR_RETRY_CNT, false,
+ rtwdev, R_AX_DBI_FLAG + 2);
+ if (ret)
+ rtw89_err(rtwdev, "failed to write DBI register, addr=0x%X\n",
+ addr);
+
+ return ret;
+}
+
+static int rtw89_dbi_read8(struct rtw89_dev *rtwdev, u16 addr, u8 *value)
+{
+ u16 read_addr = addr & B_AX_DBI_ADDR_MSK;
+ u8 flag;
+ int ret;
+
+ rtw89_write16(rtwdev, R_AX_DBI_FLAG, read_addr);
+ rtw89_write8(rtwdev, R_AX_DBI_FLAG + 2, B_AX_DBI_RFLAG >> 16);
+
+ ret = read_poll_timeout_atomic(rtw89_read8, flag, !flag, 10,
+ 10 * RTW89_PCI_WR_RETRY_CNT, false,
+ rtwdev, R_AX_DBI_FLAG + 2);
+ if (ret) {
+ rtw89_err(rtwdev, "failed to read DBI register, addr=0x%X\n",
+ addr);
+ return ret;
+ }
+
+ read_addr = R_AX_DBI_RDATA + (addr & 3);
+ *value = rtw89_read8(rtwdev, read_addr);
+
+ return 0;
+}
+
static int rtw89_pci_write_config_byte(struct rtw89_dev *rtwdev, u16 addr,
u8 data)
{
struct rtw89_pci *rtwpci = (struct rtw89_pci *)rtwdev->priv;
+ enum rtw89_core_chip_id chip_id = rtwdev->chip->chip_id;
struct pci_dev *pdev = rtwpci->pdev;
+ int ret;
+
+ ret = pci_write_config_byte(pdev, addr, data);
+ if (!ret)
+ return 0;
- return pci_write_config_byte(pdev, addr, data);
+ if (chip_id == RTL8852A || chip_id == RTL8852B || chip_id == RTL8851B)
+ ret = rtw89_dbi_write8(rtwdev, addr, data);
+
+ return ret;
}
static int rtw89_pci_read_config_byte(struct rtw89_dev *rtwdev, u16 addr,
u8 *value)
{
struct rtw89_pci *rtwpci = (struct rtw89_pci *)rtwdev->priv;
+ enum rtw89_core_chip_id chip_id = rtwdev->chip->chip_id;
struct pci_dev *pdev = rtwpci->pdev;
+ int ret;
- return pci_read_config_byte(pdev, addr, value);
+ ret = pci_read_config_byte(pdev, addr, value);
+ if (!ret)
+ return 0;
+
+ if (chip_id == RTL8852A || chip_id == RTL8852B || chip_id == RTL8851B)
+ ret = rtw89_dbi_read8(rtwdev, addr, value);
+
+ return ret;
}
static int rtw89_pci_config_byte_set(struct rtw89_dev *rtwdev, u16 addr,
diff --git a/drivers/net/wireless/realtek/rtw89/pci.h b/drivers/net/wireless/realtek/rtw89/pci.h
index ca5de77fee90..1fb7c209fa0d 100644
--- a/drivers/net/wireless/realtek/rtw89/pci.h
+++ b/drivers/net/wireless/realtek/rtw89/pci.h
@@ -42,6 +42,7 @@
#define B_AX_DBI_WFLAG BIT(16)
#define B_AX_DBI_WREN_MSK GENMASK(15, 12)
#define B_AX_DBI_ADDR_MSK GENMASK(11, 2)
+#define B_AX_DBI_2LSB GENMASK(1, 0)
#define R_AX_DBI_WDATA 0x1094
#define R_AX_DBI_RDATA 0x1098
--
2.25.1
Ping-Ke Shih <[email protected]> wrote:
> From: Chin-Yen Lee <[email protected]>
>
> Sometimes driver can't use kernel API pci_read/write_config_byte
> to access the PCI config space of above address 0x100 due to
> the negotiated PCI setting. 8852AE/8852BE/8851BE provide another
> way called DBI function, which belongs to WiFi mac and could
> access all PCI config space for this case.
>
> Link: https://lore.kernel.org/linux-wireless/[email protected]/T/#t
> Signed-off-by: Chin-Yen Lee <[email protected]>
> Signed-off-by: Ping-Ke Shih <[email protected]>
Patch applied to wireless-next.git, thanks.
9496d62f3877 wifi: rtw89: pci: use DBI function for 8852AE/8852BE/8851BE
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches