diff mbox series

[v4,02/11] net: stmmac: dwmac-stm32: Separate out external clock rate validation

Message ID 20240604143502.154463-3-christophe.roullier@foss.st.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Series to deliver Ethernet for STM32MP13 | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Guessed tree name to be net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
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: 901 this patch: 901
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 905 this patch: 905
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: 905 this patch: 905
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 88 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Christophe Roullier June 4, 2024, 2:34 p.m. UTC 
From: Marek Vasut <marex@denx.de>

Pull the external clock frequency validation into a separate function,
to avoid conflating it with external clock DT property decoding and
clock mux register configuration. This should make the code easier to
read and understand.

This does change the code behavior slightly. The clock mux PMCR register
setting now depends solely on the DT properties which configure the clock
mux between external clock and internal RCC generated clock. The mux PMCR
register settings no longer depend on the supplied clock frequency, that
supplied clock frequency is now only validated, and if the clock frequency
is invalid for a mode, it is rejected.

Previously, the code would switch the PMCR register clock mux to internal
RCC generated clock if external clock couldn't provide suitable frequency,
without checking whether the RCC generated clock frequency is correct. Such
behavior is risky at best, user should have configured their clock correctly
in the first place, so this behavior is removed here.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Christophe Roullier <christophe.roullier@foss.st.com>
---
 .../net/ethernet/stmicro/stmmac/dwmac-stm32.c | 51 +++++++++++++++----
 1 file changed, 41 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
index c92dfc4ecf570..2fd2620ebed69 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -157,25 +157,54 @@  static int stm32_dwmac_init(struct plat_stmmacenet_data *plat_dat, bool resume)
 	return stm32_dwmac_clk_enable(dwmac, resume);
 }
 
+static int stm32mp1_validate_ethck_rate(struct plat_stmmacenet_data *plat_dat)
+{
+	struct stm32_dwmac *dwmac = plat_dat->bsp_priv;
+	const u32 clk_rate = clk_get_rate(dwmac->clk_eth_ck);
+
+	switch (plat_dat->mac_interface) {
+	case PHY_INTERFACE_MODE_MII:
+	case PHY_INTERFACE_MODE_GMII:
+		if (clk_rate == ETH_CK_F_25M)
+			return 0;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		if (clk_rate == ETH_CK_F_25M || clk_rate == ETH_CK_F_50M)
+			return 0;
+		break;
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		if (clk_rate == ETH_CK_F_25M || clk_rate == ETH_CK_F_125M)
+			return 0;
+		break;
+	default:
+		break;
+	}
+
+	dev_err(dwmac->dev, "Mode %s does not match eth-ck frequency %d Hz",
+		phy_modes(plat_dat->mac_interface), clk_rate);
+	return -EINVAL;
+}
+
 static int stm32mp1_set_mode(struct plat_stmmacenet_data *plat_dat)
 {
 	struct stm32_dwmac *dwmac = plat_dat->bsp_priv;
-	u32 reg = dwmac->mode_reg, clk_rate;
-	int val;
+	u32 reg = dwmac->mode_reg;
+	int val, ret;
 
-	clk_rate = clk_get_rate(dwmac->clk_eth_ck);
 	dwmac->enable_eth_ck = false;
 	switch (plat_dat->mac_interface) {
 	case PHY_INTERFACE_MODE_MII:
-		if (clk_rate == ETH_CK_F_25M && dwmac->ext_phyclk)
+		if (dwmac->ext_phyclk)
 			dwmac->enable_eth_ck = true;
 		val = SYSCFG_PMCR_ETH_SEL_MII;
 		pr_debug("SYSCFG init : PHY_INTERFACE_MODE_MII\n");
 		break;
 	case PHY_INTERFACE_MODE_GMII:
 		val = SYSCFG_PMCR_ETH_SEL_GMII;
-		if (clk_rate == ETH_CK_F_25M &&
-		    (dwmac->eth_clk_sel_reg || dwmac->ext_phyclk)) {
+		if (dwmac->eth_clk_sel_reg || dwmac->ext_phyclk) {
 			dwmac->enable_eth_ck = true;
 			val |= SYSCFG_PMCR_ETH_CLK_SEL;
 		}
@@ -183,8 +212,7 @@  static int stm32mp1_set_mode(struct plat_stmmacenet_data *plat_dat)
 		break;
 	case PHY_INTERFACE_MODE_RMII:
 		val = SYSCFG_PMCR_ETH_SEL_RMII;
-		if ((clk_rate == ETH_CK_F_25M || clk_rate == ETH_CK_F_50M) &&
-		    (dwmac->eth_ref_clk_sel_reg || dwmac->ext_phyclk)) {
+		if (dwmac->eth_ref_clk_sel_reg || dwmac->ext_phyclk) {
 			dwmac->enable_eth_ck = true;
 			val |= SYSCFG_PMCR_ETH_REF_CLK_SEL;
 		}
@@ -195,8 +223,7 @@  static int stm32mp1_set_mode(struct plat_stmmacenet_data *plat_dat)
 	case PHY_INTERFACE_MODE_RGMII_RXID:
 	case PHY_INTERFACE_MODE_RGMII_TXID:
 		val = SYSCFG_PMCR_ETH_SEL_RGMII;
-		if ((clk_rate == ETH_CK_F_25M || clk_rate == ETH_CK_F_125M) &&
-		    (dwmac->eth_clk_sel_reg || dwmac->ext_phyclk)) {
+		if (dwmac->eth_clk_sel_reg || dwmac->ext_phyclk) {
 			dwmac->enable_eth_ck = true;
 			val |= SYSCFG_PMCR_ETH_CLK_SEL;
 		}
@@ -209,6 +236,10 @@  static int stm32mp1_set_mode(struct plat_stmmacenet_data *plat_dat)
 		return -EINVAL;
 	}
 
+	ret = stm32mp1_validate_ethck_rate(plat_dat);
+	if (ret)
+		return ret;
+
 	/* Need to update PMCCLRR (clear register) */
 	regmap_write(dwmac->regmap, reg + SYSCFG_PMCCLRR_OFFSET,
 		     dwmac->ops->syscfg_eth_mask);