diff options
Diffstat (limited to 'drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c')
-rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c | 146 |
1 files changed, 114 insertions, 32 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c index a3934ca6a043..234e8b6816ce 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-meson8b.c @@ -5,6 +5,7 @@ * Copyright (C) 2016 Martin Blumenstingl <martin.blumenstingl@googlemail.com> */ +#include <linux/bitfield.h> #include <linux/clk.h> #include <linux/clk-provider.h> #include <linux/device.h> @@ -32,7 +33,10 @@ #define PRG_ETH0_CLK_M250_SEL_SHIFT 4 #define PRG_ETH0_CLK_M250_SEL_MASK GENMASK(4, 4) -#define PRG_ETH0_TXDLY_SHIFT 5 +/* TX clock delay in ns = "8ns / 4 * tx_dly_val" (where 8ns are exactly one + * cycle of the 125MHz RGMII TX clock): + * 0ns = 0x0, 2ns = 0x1, 4ns = 0x2, 6ns = 0x3 + */ #define PRG_ETH0_TXDLY_MASK GENMASK(6, 5) /* divider for the result of m250_sel */ @@ -44,6 +48,27 @@ #define PRG_ETH0_INVERTED_RMII_CLK BIT(11) #define PRG_ETH0_TX_AND_PHY_REF_CLK BIT(12) +/* Bypass (= 0, the signal from the GPIO input directly connects to the + * internal sampling) or enable (= 1) the internal logic for RXEN and RXD[3:0] + * timing tuning. + */ +#define PRG_ETH0_ADJ_ENABLE BIT(13) +/* Controls whether the RXEN and RXD[3:0] signals should be aligned with the + * input RX rising/falling edge and sent to the Ethernet internals. This sets + * the automatically delay and skew automatically (internally). + */ +#define PRG_ETH0_ADJ_SETUP BIT(14) +/* An internal counter based on the "timing-adjustment" clock. The counter is + * cleared on both, the falling and rising edge of the RX_CLK. This selects the + * delay (= the counter value) when to start sampling RXEN and RXD[3:0]. + */ +#define PRG_ETH0_ADJ_DELAY GENMASK(19, 15) +/* Adjusts the skew between each bit of RXEN and RXD[3:0]. If a signal has a + * large input delay, the bit for that signal (RXEN = bit 0, RXD[3] = bit 1, + * ...) can be configured to be 1 to compensate for a delay of about 1ns. + */ +#define PRG_ETH0_ADJ_SKEW GENMASK(24, 20) + #define MUX_CLK_NUM_PARENTS 2 struct meson8b_dwmac; @@ -60,6 +85,8 @@ struct meson8b_dwmac { phy_interface_t phy_mode; struct clk *rgmii_tx_clk; u32 tx_delay_ns; + u32 rx_delay_ns; + struct clk *timing_adj_clk; }; struct meson8b_dwmac_clk_configs { @@ -240,30 +267,82 @@ static int meson_axg_set_phy_mode(struct meson8b_dwmac *dwmac) return 0; } +static int meson8b_devm_clk_prepare_enable(struct meson8b_dwmac *dwmac, + struct clk *clk) +{ + int ret; + + ret = clk_prepare_enable(clk); + if (ret) + return ret; + + devm_add_action_or_reset(dwmac->dev, + (void(*)(void *))clk_disable_unprepare, + dwmac->rgmii_tx_clk); + + return 0; +} + static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac) { + u32 tx_dly_config, rx_dly_config, delay_config; int ret; - u8 tx_dly_val = 0; + + tx_dly_config = FIELD_PREP(PRG_ETH0_TXDLY_MASK, + dwmac->tx_delay_ns >> 1); + + if (dwmac->rx_delay_ns == 2) + rx_dly_config = PRG_ETH0_ADJ_ENABLE | PRG_ETH0_ADJ_SETUP; + else + rx_dly_config = 0; switch (dwmac->phy_mode) { case PHY_INTERFACE_MODE_RGMII: + delay_config = tx_dly_config | rx_dly_config; + break; case PHY_INTERFACE_MODE_RGMII_RXID: - /* TX clock delay in ns = "8ns / 4 * tx_dly_val" (where - * 8ns are exactly one cycle of the 125MHz RGMII TX clock): - * 0ns = 0x0, 2ns = 0x1, 4ns = 0x2, 6ns = 0x3 - */ - tx_dly_val = dwmac->tx_delay_ns >> 1; - /* fall through */ - - case PHY_INTERFACE_MODE_RGMII_ID: + delay_config = tx_dly_config; + break; case PHY_INTERFACE_MODE_RGMII_TXID: + delay_config = rx_dly_config; + break; + case PHY_INTERFACE_MODE_RGMII_ID: + case PHY_INTERFACE_MODE_RMII: + delay_config = 0; + break; + default: + dev_err(dwmac->dev, "unsupported phy-mode %s\n", + phy_modes(dwmac->phy_mode)); + return -EINVAL; + }; + + if (rx_dly_config & PRG_ETH0_ADJ_ENABLE) { + if (!dwmac->timing_adj_clk) { + dev_err(dwmac->dev, + "The timing-adjustment clock is mandatory for the RX delay re-timing\n"); + return -EINVAL; + } + + /* The timing adjustment logic is driven by a separate clock */ + ret = meson8b_devm_clk_prepare_enable(dwmac, + dwmac->timing_adj_clk); + if (ret) { + dev_err(dwmac->dev, + "Failed to enable the timing-adjustment clock\n"); + return ret; + } + } + + meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK | + PRG_ETH0_ADJ_ENABLE | PRG_ETH0_ADJ_SETUP | + PRG_ETH0_ADJ_DELAY | PRG_ETH0_ADJ_SKEW, + delay_config); + + if (phy_interface_mode_is_rgmii(dwmac->phy_mode)) { /* only relevant for RMII mode -> disable in RGMII mode */ meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_INVERTED_RMII_CLK, 0); - meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK, - tx_dly_val << PRG_ETH0_TXDLY_SHIFT); - /* Configure the 125MHz RGMII TX clock, the IP block changes * the output automatically (= without us having to configure * a register) based on the line-speed (125MHz for Gbit speeds, @@ -276,34 +355,18 @@ static int meson8b_init_prg_eth(struct meson8b_dwmac *dwmac) return ret; } - ret = clk_prepare_enable(dwmac->rgmii_tx_clk); + ret = meson8b_devm_clk_prepare_enable(dwmac, + dwmac->rgmii_tx_clk); if (ret) { dev_err(dwmac->dev, "failed to enable the RGMII TX clock\n"); return ret; } - - devm_add_action_or_reset(dwmac->dev, - (void(*)(void *))clk_disable_unprepare, - dwmac->rgmii_tx_clk); - break; - - case PHY_INTERFACE_MODE_RMII: + } else { /* invert internal clk_rmii_i to generate 25/2.5 tx_rx_clk */ meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_INVERTED_RMII_CLK, PRG_ETH0_INVERTED_RMII_CLK); - - /* TX clock delay cannot be configured in RMII mode */ - meson8b_dwmac_mask_bits(dwmac, PRG_ETH0, PRG_ETH0_TXDLY_MASK, - 0); - - break; - - default: - dev_err(dwmac->dev, "unsupported phy-mode %s\n", - phy_modes(dwmac->phy_mode)); - return -EINVAL; } /* enable TX_CLK and PHY_REF_CLK generator */ @@ -358,6 +421,25 @@ static int meson8b_dwmac_probe(struct platform_device *pdev) &dwmac->tx_delay_ns)) dwmac->tx_delay_ns = 2; + /* use 0ns as fallback since this is what most boards actually use */ + if (of_property_read_u32(pdev->dev.of_node, "amlogic,rx-delay-ns", + &dwmac->rx_delay_ns)) + dwmac->rx_delay_ns = 0; + + if (dwmac->rx_delay_ns != 0 && dwmac->rx_delay_ns != 2) { + dev_err(&pdev->dev, + "The only allowed RX delays values are: 0ns, 2ns"); + ret = -EINVAL; + goto err_remove_config_dt; + } + + dwmac->timing_adj_clk = devm_clk_get_optional(dwmac->dev, + "timing-adjustment"); + if (IS_ERR(dwmac->timing_adj_clk)) { + ret = PTR_ERR(dwmac->timing_adj_clk); + goto err_remove_config_dt; + } + ret = meson8b_init_rgmii_tx_clk(dwmac); if (ret) goto err_remove_config_dt; |