// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019 Baylibre, SAS.
* Author: Jerome Brunet <jbrunet@baylibre.com>
*/
#include <linux/bitfield.h>
#include <linux/delay.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 0x33010180
#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 {
void __iomem *regs;
void *mux_handle;
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 even though 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 int 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);
return 0;
}
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)
{
u32 value;
int ret;
/* Enable the phy clock */
if (!__clk_is_enabled(priv->pll)) {
ret = clk_prepare_enable(priv->pll);
if (ret)
return ret;
}
/* Initialize ephy control */
writel(EPHY_G12A_ID, priv->regs + ETH_PHY_CNTL0);
/* Make sure we get a 0 -> 1 transition on the enable bit */
value = 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;
writel(value, 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);
value |= PHY_CNTL1_PHY_ENB;
writel(value, priv->regs + ETH_PHY_CNTL1);
/* The phy needs a bit of time to power up */
mdelay(10);
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 (__clk_is_enabled(priv->pll))
clk_disable_unprepare(priv->pll);
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))
return dev_err_probe(dev, PTR_ERR(clk),
"Missing clock %s\n", in_name);
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 clk *pclk;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
platform_set_drvdata(pdev, priv);
priv->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(priv->regs))
return PTR_ERR(priv->regs);
pclk = devm_clk_get_enabled(dev, "pclk");
if (IS_ERR(pclk))
return dev_err_probe(dev, PTR_ERR(pclk),
"failed to get peripheral clock\n");
/* Register PLL in CCF */
ret = g12a_ephy_glue_clk_register(dev);
if (ret)
return ret;
ret = mdio_mux_init(dev, dev->of_node, g12a_mdio_switch_fn,
&priv->mux_handle, dev, NULL);
if (ret)
dev_err_probe(dev, ret, "mdio multiplexer init failed\n");
return ret;
}
static void g12a_mdio_mux_remove(struct platform_device *pdev)
{
struct g12a_mdio_mux *priv = platform_get_drvdata(pdev);
mdio_mux_uninit(priv->mux_handle);
if (__clk_is_enabled(priv->pll))
clk_disable_unprepare(priv->pll);
}
static struct platform_driver g12a_mdio_mux_driver = {
.probe = g12a_mdio_mux_probe,
.remove_new = 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");
