From c05ec3d4d7df57ff286917f7fb54aec6fa4691c5 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Sat, 8 Jun 2019 19:12:28 +0300 Subject: net: dsa: sja1105: Add RGMII delay support for P/Q/R/S chips As per the DT phy-mode specification, RGMII delays are applied by the MAC when there is no PHY present on the link. Signed-off-by: Vladimir Oltean Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/dsa/sja1105/sja1105_clocking.c | 98 +++++++++++++++++++++++++++++- 1 file changed, 96 insertions(+), 2 deletions(-) (limited to 'drivers/net/dsa/sja1105/sja1105_clocking.c') diff --git a/drivers/net/dsa/sja1105/sja1105_clocking.c b/drivers/net/dsa/sja1105/sja1105_clocking.c index 5c7cea22b647..608126a15d72 100644 --- a/drivers/net/dsa/sja1105/sja1105_clocking.c +++ b/drivers/net/dsa/sja1105/sja1105_clocking.c @@ -19,6 +19,17 @@ struct sja1105_cfg_pad_mii_tx { u64 clk_ipud; }; +struct sja1105_cfg_pad_mii_id { + u64 rxc_stable_ovr; + u64 rxc_delay; + u64 rxc_bypass; + u64 rxc_pd; + u64 txc_stable_ovr; + u64 txc_delay; + u64 txc_bypass; + u64 txc_pd; +}; + /* UM10944 Table 82. * IDIV_0_C to IDIV_4_C control registers * (addr. 10000Bh to 10000Fh) @@ -377,7 +388,84 @@ static int sja1105_rgmii_cfg_pad_tx_config(struct sja1105_private *priv, packed_buf, SJA1105_SIZE_CGU_CMD); } -static int sja1105_rgmii_clocking_setup(struct sja1105_private *priv, int port) +static void +sja1105_cfg_pad_mii_id_packing(void *buf, struct sja1105_cfg_pad_mii_id *cmd, + enum packing_op op) +{ + const int size = SJA1105_SIZE_CGU_CMD; + + sja1105_packing(buf, &cmd->rxc_stable_ovr, 15, 15, size, op); + sja1105_packing(buf, &cmd->rxc_delay, 14, 10, size, op); + sja1105_packing(buf, &cmd->rxc_bypass, 9, 9, size, op); + sja1105_packing(buf, &cmd->rxc_pd, 8, 8, size, op); + sja1105_packing(buf, &cmd->txc_stable_ovr, 7, 7, size, op); + sja1105_packing(buf, &cmd->txc_delay, 6, 2, size, op); + sja1105_packing(buf, &cmd->txc_bypass, 1, 1, size, op); + sja1105_packing(buf, &cmd->txc_pd, 0, 0, size, op); +} + +/* Valid range in degrees is an integer between 73.8 and 101.7 */ +static inline u64 sja1105_rgmii_delay(u64 phase) +{ + /* UM11040.pdf: The delay in degree phase is 73.8 + delay_tune * 0.9. + * To avoid floating point operations we'll multiply by 10 + * and get 1 decimal point precision. + */ + phase *= 10; + return (phase - 738) / 9; +} + +/* The RGMII delay setup procedure is 2-step and gets called upon each + * .phylink_mac_config. Both are strategic. + * The reason is that the RX Tunable Delay Line of the SJA1105 MAC has issues + * with recovering from a frequency change of the link partner's RGMII clock. + * The easiest way to recover from this is to temporarily power down the TDL, + * as it will re-lock at the new frequency afterwards. + */ +int sja1105pqrs_setup_rgmii_delay(const void *ctx, int port) +{ + const struct sja1105_private *priv = ctx; + const struct sja1105_regs *regs = priv->info->regs; + struct sja1105_cfg_pad_mii_id pad_mii_id = {0}; + u8 packed_buf[SJA1105_SIZE_CGU_CMD] = {0}; + int rc; + + if (priv->rgmii_rx_delay[port]) + pad_mii_id.rxc_delay = sja1105_rgmii_delay(90); + if (priv->rgmii_tx_delay[port]) + pad_mii_id.txc_delay = sja1105_rgmii_delay(90); + + /* Stage 1: Turn the RGMII delay lines off. */ + pad_mii_id.rxc_bypass = 1; + pad_mii_id.rxc_pd = 1; + pad_mii_id.txc_bypass = 1; + pad_mii_id.txc_pd = 1; + sja1105_cfg_pad_mii_id_packing(packed_buf, &pad_mii_id, PACK); + + rc = sja1105_spi_send_packed_buf(priv, SPI_WRITE, + regs->pad_mii_id[port], + packed_buf, SJA1105_SIZE_CGU_CMD); + if (rc < 0) + return rc; + + /* Stage 2: Turn the RGMII delay lines on. */ + if (priv->rgmii_rx_delay[port]) { + pad_mii_id.rxc_bypass = 0; + pad_mii_id.rxc_pd = 0; + } + if (priv->rgmii_tx_delay[port]) { + pad_mii_id.txc_bypass = 0; + pad_mii_id.txc_pd = 0; + } + sja1105_cfg_pad_mii_id_packing(packed_buf, &pad_mii_id, PACK); + + return sja1105_spi_send_packed_buf(priv, SPI_WRITE, + regs->pad_mii_id[port], + packed_buf, SJA1105_SIZE_CGU_CMD); +} + +static int sja1105_rgmii_clocking_setup(struct sja1105_private *priv, int port, + sja1105_mii_role_t role) { struct device *dev = priv->ds->dev; struct sja1105_mac_config_entry *mac; @@ -429,6 +517,12 @@ static int sja1105_rgmii_clocking_setup(struct sja1105_private *priv, int port) } if (!priv->info->setup_rgmii_delay) return 0; + /* The role has no hardware effect for RGMII. However we use it as + * a proxy for this interface being a MAC-to-MAC connection, with + * the RGMII internal delays needing to be applied by us. + */ + if (role == XMII_MAC) + return 0; return priv->info->setup_rgmii_delay(priv, port); } @@ -575,7 +669,7 @@ int sja1105_clocking_setup_port(struct sja1105_private *priv, int port) rc = sja1105_rmii_clocking_setup(priv, port, role); break; case XMII_MODE_RGMII: - rc = sja1105_rgmii_clocking_setup(priv, port); + rc = sja1105_rgmii_clocking_setup(priv, port, role); break; default: dev_err(dev, "Invalid interface mode specified: %d\n", -- cgit