From b99ed2766ae7bfc28077b8e2ce90ce2402483195 Mon Sep 17 00:00:00 2001 From: Nikolay Dimitrov Date: Sun, 12 Oct 2014 13:47:51 +0300 Subject: [PATCH] novena: Fix ethernet PHY reset sequence This patch fixes conflict between PHY pins becoming outputs after reset and imx6 still driving the pins. It also fixes the reset timing as recommended by the PHY datasheet. Signed-off-by: Nikolay Dimitrov Cc: Stefano Babic Cc: Sean Cross Cc: Marek Vasut Reviewed-by: Fabio Estevam --- board/kosagi/novena/novena.c | 3 -- board/kosagi/novena/novena_spl.c | 64 +++++++++++++++++++++++++++++----------- 2 files changed, 46 insertions(+), 21 deletions(-) diff --git a/board/kosagi/novena/novena.c b/board/kosagi/novena/novena.c index 2361a3c..6add9e5 100644 --- a/board/kosagi/novena/novena.c +++ b/board/kosagi/novena/novena.c @@ -237,9 +237,6 @@ int board_early_init_f(void) setup_display(); #endif - /* Bring Ethernet PHY out of reset. */ - gpio_set_value(IMX_GPIO_NR(3, 23), 1); - return 0; } diff --git a/board/kosagi/novena/novena_spl.c b/board/kosagi/novena/novena_spl.c index a8389d9..c4155dd 100644 --- a/board/kosagi/novena/novena_spl.c +++ b/board/kosagi/novena/novena_spl.c @@ -41,6 +41,10 @@ DECLARE_GLOBAL_DATA_PTR; PAD_CTL_PUS_100K_UP | PAD_CTL_SPEED_MED | \ PAD_CTL_DSE_40ohm | PAD_CTL_HYS) +#define ENET_PHY_CFG_PAD_CTRL \ + (PAD_CTL_PKE | PAD_CTL_PUE | \ + PAD_CTL_PUS_22K_UP | PAD_CTL_HYS) + #define RGMII_PAD_CTRL \ (PAD_CTL_PKE | PAD_CTL_PUE | \ PAD_CTL_PUS_100K_UP | PAD_CTL_DSE_40ohm | PAD_CTL_HYS) @@ -98,18 +102,20 @@ static iomux_v3_cfg_t enet_pads1[] = { MX6_PAD_RGMII_TD3__RGMII_TD3 | MUX_PAD_CTRL(RGMII_PAD_CTRL), MX6_PAD_RGMII_TX_CTL__RGMII_TX_CTL | MUX_PAD_CTRL(RGMII_PAD_CTRL), MX6_PAD_ENET_REF_CLK__ENET_TX_CLK | MUX_PAD_CTRL(ENET_PAD_CTRL), - /* pin 35 - 1 (PHY_AD2) on reset */ - MX6_PAD_RGMII_RXC__GPIO6_IO30 | MUX_PAD_CTRL(NO_PAD_CTRL), - /* pin 32 - 1 - (MODE0) all */ - MX6_PAD_RGMII_RD0__GPIO6_IO25 | MUX_PAD_CTRL(NO_PAD_CTRL), - /* pin 31 - 1 - (MODE1) all */ - MX6_PAD_RGMII_RD1__GPIO6_IO27 | MUX_PAD_CTRL(NO_PAD_CTRL), - /* pin 28 - 1 - (MODE2) all */ - MX6_PAD_RGMII_RD2__GPIO6_IO28 | MUX_PAD_CTRL(NO_PAD_CTRL), - /* pin 27 - 1 - (MODE3) all */ - MX6_PAD_RGMII_RD3__GPIO6_IO29 | MUX_PAD_CTRL(NO_PAD_CTRL), - /* pin 33 - 1 - (CLK125_EN) 125Mhz clockout enabled */ - MX6_PAD_RGMII_RX_CTL__GPIO6_IO24 | MUX_PAD_CTRL(NO_PAD_CTRL), + + /* pin 35, PHY_AD2 */ + MX6_PAD_RGMII_RXC__GPIO6_IO30 | MUX_PAD_CTRL(ENET_PHY_CFG_PAD_CTRL), + /* pin 32, MODE0 */ + MX6_PAD_RGMII_RD0__GPIO6_IO25 | MUX_PAD_CTRL(ENET_PHY_CFG_PAD_CTRL), + /* pin 31, MODE1 */ + MX6_PAD_RGMII_RD1__GPIO6_IO27 | MUX_PAD_CTRL(ENET_PHY_CFG_PAD_CTRL), + /* pin 28, MODE2 */ + MX6_PAD_RGMII_RD2__GPIO6_IO28 | MUX_PAD_CTRL(ENET_PHY_CFG_PAD_CTRL), + /* pin 27, MODE3 */ + MX6_PAD_RGMII_RD3__GPIO6_IO29 | MUX_PAD_CTRL(ENET_PHY_CFG_PAD_CTRL), + /* pin 33, CLK125_EN */ + MX6_PAD_RGMII_RX_CTL__GPIO6_IO24 | MUX_PAD_CTRL(ENET_PHY_CFG_PAD_CTRL), + /* pin 42 PHY nRST */ MX6_PAD_EIM_D23__GPIO3_IO23 | MUX_PAD_CTRL(NO_PAD_CTRL), }; @@ -127,15 +133,37 @@ static void novena_spl_setup_iomux_enet(void) { imx_iomux_v3_setup_multiple_pads(enet_pads1, ARRAY_SIZE(enet_pads1)); + /* Assert Ethernet PHY nRST */ gpio_direction_output(IMX_GPIO_NR(3, 23), 0); - gpio_direction_output(IMX_GPIO_NR(6, 30), 1); - gpio_direction_output(IMX_GPIO_NR(6, 25), 1); - gpio_direction_output(IMX_GPIO_NR(6, 27), 1); - gpio_direction_output(IMX_GPIO_NR(6, 28), 1); - gpio_direction_output(IMX_GPIO_NR(6, 29), 1); - gpio_direction_output(IMX_GPIO_NR(6, 24), 1); + /* + * Use imx6 internal pull-ups to drive PHY mode pins during PHY reset + * de-assertion. The intention is to use weak signal drivers (pull-ups) + * to prevent the conflict between PHY pins becoming outputs after + * reset and imx6 still driving the pins. The issue is described in PHY + * datasheet, p.14 + */ + gpio_direction_input(IMX_GPIO_NR(6, 30)); /* PHY_AD2 = 1 */ + gpio_direction_input(IMX_GPIO_NR(6, 25)); /* MODE0 = 1 */ + gpio_direction_input(IMX_GPIO_NR(6, 27)); /* MODE1 = 1 */ + gpio_direction_input(IMX_GPIO_NR(6, 28)); /* MODE2 = 1 */ + gpio_direction_input(IMX_GPIO_NR(6, 29)); /* MODE3 = 1 */ + gpio_direction_input(IMX_GPIO_NR(6, 24)); /* CLK125_EN = 1 */ + + /* Following reset timing (p.53, fig.8 from the PHY datasheet) */ + mdelay(10); + + /* De-assert Ethernet PHY nRST */ + gpio_set_value(IMX_GPIO_NR(3, 23), 1); + + /* PHY is now configured, connect FEC to the pads */ imx_iomux_v3_setup_multiple_pads(enet_pads2, ARRAY_SIZE(enet_pads2)); + + /* + * PHY datasheet recommends on p.53 to wait at least 100us after reset + * before using MII, so we enforce the delay here + */ + udelay(100); } /* -- 2.7.4