net: phy: add amlogic g12a mdio mux support
authorJerome Brunet <jbrunet@baylibre.com>
Thu, 4 Apr 2019 13:11:45 +0000 (15:11 +0200)
committerDavid S. Miller <davem@davemloft.net>
Sun, 7 Apr 2019 01:16:58 +0000 (18:16 -0700)
Add support for the mdio mux and internal phy glue of the g12a SoC family

Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> # clk parts
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/phy/Kconfig
drivers/net/phy/Makefile
drivers/net/phy/mdio-mux-meson-g12a.c [new file with mode: 0644]

index 1c66e92c717cbac7d0f4dc85260be39aa3ab1e26..d408b2eb29664785a7d72e53ded1e48a6b2e716f 100644 (file)
@@ -76,6 +76,17 @@ config MDIO_BUS_MUX_GPIO
          several child MDIO busses to a parent bus.  Child bus
          selection is under the control of GPIO lines.
 
+config MDIO_BUS_MUX_MESON_G12A
+       tristate "Amlogic G12a based MDIO bus multiplexer"
+       depends on ARCH_MESON || COMPILE_TEST
+       depends on OF_MDIO && HAS_IOMEM && COMMON_CLK
+       select MDIO_BUS_MUX
+       default m if ARCH_MESON
+       help
+         This module provides a driver for the MDIO multiplexer/glue of
+         the amlogic g12a SoC. The multiplexers connects either the external
+         or the internal MDIO bus to the parent bus.
+
 config MDIO_BUS_MUX_MMIOREG
        tristate "MMIO device-controlled MDIO bus multiplexers"
        depends on OF_MDIO && HAS_IOMEM
index ece5dae67174f87362e7950fcd4171b3c0c63d65..27d7f9f3b0de4c820ce1fdb6f7b1237df3601f5a 100644 (file)
@@ -28,6 +28,7 @@ obj-$(CONFIG_MDIO_BITBANG)    += mdio-bitbang.o
 obj-$(CONFIG_MDIO_BUS_MUX)     += mdio-mux.o
 obj-$(CONFIG_MDIO_BUS_MUX_BCM_IPROC)   += mdio-mux-bcm-iproc.o
 obj-$(CONFIG_MDIO_BUS_MUX_GPIO)        += mdio-mux-gpio.o
+obj-$(CONFIG_MDIO_BUS_MUX_MESON_G12A)  += mdio-mux-meson-g12a.o
 obj-$(CONFIG_MDIO_BUS_MUX_MMIOREG) += mdio-mux-mmioreg.o
 obj-$(CONFIG_MDIO_BUS_MUX_MULTIPLEXER) += mdio-mux-multiplexer.o
 obj-$(CONFIG_MDIO_CAVIUM)      += mdio-cavium.o
diff --git a/drivers/net/phy/mdio-mux-meson-g12a.c b/drivers/net/phy/mdio-mux-meson-g12a.c
new file mode 100644 (file)
index 0000000..6fa29ea
--- /dev/null
@@ -0,0 +1,380 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Baylibre, SAS.
+ * Author: Jerome Brunet <jbrunet@baylibre.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/mdio-mux.h>
+#include <linux/module.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+
+#define ETH_PLL_STS            0x40
+#define ETH_PLL_CTL0           0x44
+#define  PLL_CTL0_LOCK_DIG     BIT(30)
+#define  PLL_CTL0_RST          BIT(29)
+#define  PLL_CTL0_EN           BIT(28)
+#define  PLL_CTL0_SEL          BIT(23)
+#define  PLL_CTL0_N            GENMASK(14, 10)
+#define  PLL_CTL0_M            GENMASK(8, 0)
+#define  PLL_LOCK_TIMEOUT      1000000
+#define  PLL_MUX_NUM_PARENT    2
+#define ETH_PLL_CTL1           0x48
+#define ETH_PLL_CTL2           0x4c
+#define ETH_PLL_CTL3           0x50
+#define ETH_PLL_CTL4           0x54
+#define ETH_PLL_CTL5           0x58
+#define ETH_PLL_CTL6           0x5c
+#define ETH_PLL_CTL7           0x60
+
+#define ETH_PHY_CNTL0          0x80
+#define   EPHY_G12A_ID         0x33000180
+#define ETH_PHY_CNTL1          0x84
+#define  PHY_CNTL1_ST_MODE     GENMASK(2, 0)
+#define  PHY_CNTL1_ST_PHYADD   GENMASK(7, 3)
+#define   EPHY_DFLT_ADD                8
+#define  PHY_CNTL1_MII_MODE    GENMASK(15, 14)
+#define   EPHY_MODE_RMII       0x1
+#define  PHY_CNTL1_CLK_EN      BIT(16)
+#define  PHY_CNTL1_CLKFREQ     BIT(17)
+#define  PHY_CNTL1_PHY_ENB     BIT(18)
+#define ETH_PHY_CNTL2          0x88
+#define  PHY_CNTL2_USE_INTERNAL        BIT(5)
+#define  PHY_CNTL2_SMI_SRC_MAC BIT(6)
+#define  PHY_CNTL2_RX_CLK_EPHY BIT(9)
+
+#define MESON_G12A_MDIO_EXTERNAL_ID 0
+#define MESON_G12A_MDIO_INTERNAL_ID 1
+
+struct g12a_mdio_mux {
+       bool pll_is_enabled;
+       void __iomem *regs;
+       void *mux_handle;
+       struct clk *pclk;
+       struct clk *pll;
+};
+
+struct g12a_ephy_pll {
+       void __iomem *base;
+       struct clk_hw hw;
+};
+
+#define g12a_ephy_pll_to_dev(_hw)                      \
+       container_of(_hw, struct g12a_ephy_pll, hw)
+
+static unsigned long g12a_ephy_pll_recalc_rate(struct clk_hw *hw,
+                                              unsigned long parent_rate)
+{
+       struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
+       u32 val, m, n;
+
+       val = readl(pll->base + ETH_PLL_CTL0);
+       m = FIELD_GET(PLL_CTL0_M, val);
+       n = FIELD_GET(PLL_CTL0_N, val);
+
+       return parent_rate * m / n;
+}
+
+static int g12a_ephy_pll_enable(struct clk_hw *hw)
+{
+       struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
+       u32 val = readl(pll->base + ETH_PLL_CTL0);
+
+       /* Apply both enable an reset */
+       val |= PLL_CTL0_RST | PLL_CTL0_EN;
+       writel(val, pll->base + ETH_PLL_CTL0);
+
+       /* Clear the reset to let PLL lock */
+       val &= ~PLL_CTL0_RST;
+       writel(val, pll->base + ETH_PLL_CTL0);
+
+       /* Poll on the digital lock instead of the usual analog lock
+        * This is done because bit 31 is unreliable on some SoC. Bit
+        * 31 may indicate that the PLL is not lock eventhough the clock
+        * is actually running
+        */
+       return readl_poll_timeout(pll->base + ETH_PLL_CTL0, val,
+                                 val & PLL_CTL0_LOCK_DIG, 0, PLL_LOCK_TIMEOUT);
+}
+
+static void g12a_ephy_pll_disable(struct clk_hw *hw)
+{
+       struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
+       u32 val;
+
+       val = readl(pll->base + ETH_PLL_CTL0);
+       val &= ~PLL_CTL0_EN;
+       val |= PLL_CTL0_RST;
+       writel(val, pll->base + ETH_PLL_CTL0);
+}
+
+static int g12a_ephy_pll_is_enabled(struct clk_hw *hw)
+{
+       struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
+       unsigned int val;
+
+       val = readl(pll->base + ETH_PLL_CTL0);
+
+       return (val & PLL_CTL0_LOCK_DIG) ? 1 : 0;
+}
+
+static void g12a_ephy_pll_init(struct clk_hw *hw)
+{
+       struct g12a_ephy_pll *pll = g12a_ephy_pll_to_dev(hw);
+
+       /* Apply PLL HW settings */
+       writel(0x29c0040a, pll->base + ETH_PLL_CTL0);
+       writel(0x927e0000, pll->base + ETH_PLL_CTL1);
+       writel(0xac5f49e5, pll->base + ETH_PLL_CTL2);
+       writel(0x00000000, pll->base + ETH_PLL_CTL3);
+       writel(0x00000000, pll->base + ETH_PLL_CTL4);
+       writel(0x20200000, pll->base + ETH_PLL_CTL5);
+       writel(0x0000c002, pll->base + ETH_PLL_CTL6);
+       writel(0x00000023, pll->base + ETH_PLL_CTL7);
+}
+
+static const struct clk_ops g12a_ephy_pll_ops = {
+       .recalc_rate    = g12a_ephy_pll_recalc_rate,
+       .is_enabled     = g12a_ephy_pll_is_enabled,
+       .enable         = g12a_ephy_pll_enable,
+       .disable        = g12a_ephy_pll_disable,
+       .init           = g12a_ephy_pll_init,
+};
+
+static int g12a_enable_internal_mdio(struct g12a_mdio_mux *priv)
+{
+       int ret;
+
+       /* Enable the phy clock */
+       if (!priv->pll_is_enabled) {
+               ret = clk_prepare_enable(priv->pll);
+               if (ret)
+                       return ret;
+       }
+
+       priv->pll_is_enabled = true;
+
+       /* Initialize ephy control */
+       writel(EPHY_G12A_ID, priv->regs + ETH_PHY_CNTL0);
+       writel(FIELD_PREP(PHY_CNTL1_ST_MODE, 3) |
+              FIELD_PREP(PHY_CNTL1_ST_PHYADD, EPHY_DFLT_ADD) |
+              FIELD_PREP(PHY_CNTL1_MII_MODE, EPHY_MODE_RMII) |
+              PHY_CNTL1_CLK_EN |
+              PHY_CNTL1_CLKFREQ |
+              PHY_CNTL1_PHY_ENB,
+              priv->regs + ETH_PHY_CNTL1);
+       writel(PHY_CNTL2_USE_INTERNAL |
+              PHY_CNTL2_SMI_SRC_MAC |
+              PHY_CNTL2_RX_CLK_EPHY,
+              priv->regs + ETH_PHY_CNTL2);
+
+       return 0;
+}
+
+static int g12a_enable_external_mdio(struct g12a_mdio_mux *priv)
+{
+       /* Reset the mdio bus mux */
+       writel_relaxed(0x0, priv->regs + ETH_PHY_CNTL2);
+
+       /* Disable the phy clock if enabled */
+       if (priv->pll_is_enabled) {
+               clk_disable_unprepare(priv->pll);
+               priv->pll_is_enabled = false;
+       }
+
+       return 0;
+}
+
+static int g12a_mdio_switch_fn(int current_child, int desired_child,
+                              void *data)
+{
+       struct g12a_mdio_mux *priv = dev_get_drvdata(data);
+
+       if (current_child == desired_child)
+               return 0;
+
+       switch (desired_child) {
+       case MESON_G12A_MDIO_EXTERNAL_ID:
+               return g12a_enable_external_mdio(priv);
+       case MESON_G12A_MDIO_INTERNAL_ID:
+               return g12a_enable_internal_mdio(priv);
+       default:
+               return -EINVAL;
+       }
+}
+
+static const struct of_device_id g12a_mdio_mux_match[] = {
+       { .compatible = "amlogic,g12a-mdio-mux", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, g12a_mdio_mux_match);
+
+static int g12a_ephy_glue_clk_register(struct device *dev)
+{
+       struct g12a_mdio_mux *priv = dev_get_drvdata(dev);
+       const char *parent_names[PLL_MUX_NUM_PARENT];
+       struct clk_init_data init;
+       struct g12a_ephy_pll *pll;
+       struct clk_mux *mux;
+       struct clk *clk;
+       char *name;
+       int i;
+
+       /* get the mux parents */
+       for (i = 0; i < PLL_MUX_NUM_PARENT; i++) {
+               char in_name[8];
+
+               snprintf(in_name, sizeof(in_name), "clkin%d", i);
+               clk = devm_clk_get(dev, in_name);
+               if (IS_ERR(clk)) {
+                       if (PTR_ERR(clk) != -EPROBE_DEFER)
+                               dev_err(dev, "Missing clock %s\n", in_name);
+                       return PTR_ERR(clk);
+               }
+
+               parent_names[i] = __clk_get_name(clk);
+       }
+
+       /* create the input mux */
+       mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+       if (!mux)
+               return -ENOMEM;
+
+       name = kasprintf(GFP_KERNEL, "%s#mux", dev_name(dev));
+       if (!name)
+               return -ENOMEM;
+
+       init.name = name;
+       init.ops = &clk_mux_ro_ops;
+       init.flags = 0;
+       init.parent_names = parent_names;
+       init.num_parents = PLL_MUX_NUM_PARENT;
+
+       mux->reg = priv->regs + ETH_PLL_CTL0;
+       mux->shift = __ffs(PLL_CTL0_SEL);
+       mux->mask = PLL_CTL0_SEL >> mux->shift;
+       mux->hw.init = &init;
+
+       clk = devm_clk_register(dev, &mux->hw);
+       kfree(name);
+       if (IS_ERR(clk)) {
+               dev_err(dev, "failed to register input mux\n");
+               return PTR_ERR(clk);
+       }
+
+       /* create the pll */
+       pll = devm_kzalloc(dev, sizeof(*pll), GFP_KERNEL);
+       if (!pll)
+               return -ENOMEM;
+
+       name = kasprintf(GFP_KERNEL, "%s#pll", dev_name(dev));
+       if (!name)
+               return -ENOMEM;
+
+       init.name = name;
+       init.ops = &g12a_ephy_pll_ops;
+       init.flags = 0;
+       parent_names[0] = __clk_get_name(clk);
+       init.parent_names = parent_names;
+       init.num_parents = 1;
+
+       pll->base = priv->regs;
+       pll->hw.init = &init;
+
+       clk = devm_clk_register(dev, &pll->hw);
+       kfree(name);
+       if (IS_ERR(clk)) {
+               dev_err(dev, "failed to register input mux\n");
+               return PTR_ERR(clk);
+       }
+
+       priv->pll = clk;
+
+       return 0;
+}
+
+static int g12a_mdio_mux_probe(struct platform_device *pdev)
+{
+       struct device *dev = &pdev->dev;
+       struct g12a_mdio_mux *priv;
+       struct resource *res;
+       int ret;
+
+       priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+       if (!priv)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, priv);
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       priv->regs = devm_ioremap_resource(dev, res);
+       if (IS_ERR(priv->regs))
+               return PTR_ERR(priv->regs);
+
+       priv->pclk = devm_clk_get(dev, "pclk");
+       if (IS_ERR(priv->pclk)) {
+               ret = PTR_ERR(priv->pclk);
+               if (ret != -EPROBE_DEFER)
+                       dev_err(dev, "failed to get peripheral clock\n");
+               return ret;
+       }
+
+       /* Make sure the device registers are clocked */
+       ret = clk_prepare_enable(priv->pclk);
+       if (ret) {
+               dev_err(dev, "failed to enable peripheral clock");
+               return ret;
+       }
+
+       /* Register PLL in CCF */
+       ret = g12a_ephy_glue_clk_register(dev);
+       if (ret)
+               goto err;
+
+       ret = mdio_mux_init(dev, dev->of_node, g12a_mdio_switch_fn,
+                           &priv->mux_handle, dev, NULL);
+       if (ret) {
+               if (ret != -EPROBE_DEFER)
+                       dev_err(dev, "mdio multiplexer init failed: %d", ret);
+               goto err;
+       }
+
+       return 0;
+
+err:
+       clk_disable_unprepare(priv->pclk);
+       return ret;
+}
+
+static int g12a_mdio_mux_remove(struct platform_device *pdev)
+{
+       struct g12a_mdio_mux *priv = platform_get_drvdata(pdev);
+
+       mdio_mux_uninit(priv->mux_handle);
+
+       if (priv->pll_is_enabled)
+               clk_disable_unprepare(priv->pll);
+
+       clk_disable_unprepare(priv->pclk);
+
+       return 0;
+}
+
+static struct platform_driver g12a_mdio_mux_driver = {
+       .probe          = g12a_mdio_mux_probe,
+       .remove         = g12a_mdio_mux_remove,
+       .driver         = {
+               .name   = "g12a-mdio_mux",
+               .of_match_table = g12a_mdio_mux_match,
+       },
+};
+module_platform_driver(g12a_mdio_mux_driver);
+
+MODULE_DESCRIPTION("Amlogic G12a MDIO multiplexer driver");
+MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
+MODULE_LICENSE("GPL v2");