diff mbox series

[v5,net-next,2/2] net: stmmac: dwmac-imx: pause the TXC clock in fixed-link

Message ID 20230807160716.259072-3-shenwei.wang@nxp.com (mailing list archive)
State Accepted
Commit 4fa6c976158b20eb7da94d35dfe34deec4b2a504
Delegated to: Netdev Maintainers
Headers show
Series update stmmac fix_mac_speed | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1330 this patch: 1330
netdev/cc_maintainers success CCed 15 of 15 maintainers
netdev/build_clang success Errors and warnings before: 1353 this patch: 1353
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1353 this patch: 1353
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns WARNING: line length of 84 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Shenwei Wang Aug. 7, 2023, 4:07 p.m. UTC 
When using a fixed-link setup, certain devices like the SJA1105 require a
small pause in the TXC clock line to enable their internal tunable
delay line (TDL).

To satisfy this requirement, this patch temporarily disables the TX clock,
and restarts it after a required period. This provides the required
silent interval on the clock line for SJA1105 to complete the frequency
transition and enable the internal TDLs. This action occurs before the link
is built up, so it does not impact a normal device too. There is no
need to identify if the connected device is an SJA1105 alike or not during
the implementation.

So far we have only enabled this feature on the i.MX93 platform.

Signed-off-by: Shenwei Wang <shenwei.wang@nxp.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-imx.c   | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
index 3eb6b4457494..43ff19b009d4 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-imx.c
@@ -32,6 +32,7 @@ 
 #define GPR_ENET_QOS_RGMII_EN		(0x1 << 21)
 
 #define MX93_GPR_ENET_QOS_INTF_MODE_MASK	GENMASK(3, 0)
+#define MX93_GPR_ENET_QOS_INTF_MASK		GENMASK(3, 1)
 #define MX93_GPR_ENET_QOS_INTF_SEL_MII		(0x0 << 1)
 #define MX93_GPR_ENET_QOS_INTF_SEL_RMII		(0x4 << 1)
 #define MX93_GPR_ENET_QOS_INTF_SEL_RGMII	(0x1 << 1)
@@ -40,6 +41,7 @@ 
 #define DMA_BUS_MODE			0x00001000
 #define DMA_BUS_MODE_SFT_RESET		(0x1 << 0)
 #define RMII_RESET_SPEED		(0x3 << 14)
+#define CTRL_SPEED_MASK			GENMASK(15, 14)
 
 struct imx_dwmac_ops {
 	u32 addr_width;
@@ -47,6 +49,7 @@  struct imx_dwmac_ops {
 
 	int (*fix_soc_reset)(void *priv, void __iomem *ioaddr);
 	int (*set_intf_mode)(struct plat_stmmacenet_data *plat_dat);
+	void (*fix_mac_speed)(void *priv, unsigned int speed, unsigned int mode);
 };
 
 struct imx_priv_data {
@@ -56,6 +59,7 @@  struct imx_priv_data {
 	struct regmap *intf_regmap;
 	u32 intf_reg_off;
 	bool rmii_refclk_ext;
+	void __iomem *base_addr;
 
 	const struct imx_dwmac_ops *ops;
 	struct plat_stmmacenet_data *plat_dat;
@@ -212,6 +216,41 @@  static void imx_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int mod
 		dev_err(dwmac->dev, "failed to set tx rate %lu\n", rate);
 }
 
+static void imx93_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int mode)
+{
+	struct imx_priv_data *dwmac = priv;
+	unsigned int iface;
+	int ctrl, old_ctrl;
+
+	imx_dwmac_fix_speed(priv, speed, mode);
+
+	if (!dwmac || mode != MLO_AN_FIXED)
+		return;
+
+	if (regmap_read(dwmac->intf_regmap, dwmac->intf_reg_off, &iface))
+		return;
+
+	iface &= MX93_GPR_ENET_QOS_INTF_MASK;
+	if (iface != MX93_GPR_ENET_QOS_INTF_SEL_RGMII)
+		return;
+
+	old_ctrl = readl(dwmac->base_addr + MAC_CTRL_REG);
+	ctrl = old_ctrl & ~CTRL_SPEED_MASK;
+	regmap_update_bits(dwmac->intf_regmap, dwmac->intf_reg_off,
+			   MX93_GPR_ENET_QOS_INTF_MODE_MASK, 0);
+	writel(ctrl, dwmac->base_addr + MAC_CTRL_REG);
+
+	 /* Ensure the settings for CTRL are applied. */
+	readl(dwmac->base_addr + MAC_CTRL_REG);
+
+	usleep_range(10, 20);
+	iface |= MX93_GPR_ENET_QOS_CLK_GEN_EN;
+	regmap_update_bits(dwmac->intf_regmap, dwmac->intf_reg_off,
+			   MX93_GPR_ENET_QOS_INTF_MODE_MASK, iface);
+
+	writel(old_ctrl, dwmac->base_addr + MAC_CTRL_REG);
+}
+
 static int imx_dwmac_mx93_reset(void *priv, void __iomem *ioaddr)
 {
 	struct plat_stmmacenet_data *plat_dat = priv;
@@ -319,6 +358,7 @@  static int imx_dwmac_probe(struct platform_device *pdev)
 	plat_dat->fix_mac_speed = imx_dwmac_fix_speed;
 	plat_dat->bsp_priv = dwmac;
 	dwmac->plat_dat = plat_dat;
+	dwmac->base_addr = stmmac_res.addr;
 
 	ret = imx_dwmac_clks_config(dwmac, true);
 	if (ret)
@@ -328,6 +368,8 @@  static int imx_dwmac_probe(struct platform_device *pdev)
 	if (ret)
 		goto err_dwmac_init;
 
+	if (dwmac->ops->fix_mac_speed)
+		plat_dat->fix_mac_speed = dwmac->ops->fix_mac_speed;
 	dwmac->plat_dat->fix_soc_reset = dwmac->ops->fix_soc_reset;
 
 	ret = stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
@@ -364,6 +406,7 @@  static struct imx_dwmac_ops imx93_dwmac_data = {
 	.mac_rgmii_txclk_auto_adj = true,
 	.set_intf_mode = imx93_set_intf_mode,
 	.fix_soc_reset = imx_dwmac_mx93_reset,
+	.fix_mac_speed = imx93_dwmac_fix_speed,
 };
 
 static const struct of_device_id imx_dwmac_match[] = {