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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Microchip LAN966x SoC Clock driver.
*
* Copyright (C) 2021 Microchip Technology, Inc. and its subsidiaries
*
* Author: Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>
*/
#include <linux/bitfield.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <dt-bindings/clock/microchip,lan966x.h>
#define GCK_ENA BIT(0)
#define GCK_SRC_SEL GENMASK(9, 8)
#define GCK_PRESCALER GENMASK(23, 16)
#define DIV_MAX 255
static const char *clk_names[N_CLOCKS] = {
"qspi0", "qspi1", "qspi2", "sdmmc0",
"pi", "mcan0", "mcan1", "flexcom0",
"flexcom1", "flexcom2", "flexcom3",
"flexcom4", "timer1", "usb_refclk",
};
struct lan966x_gck {
struct clk_hw hw;
void __iomem *reg;
};
#define to_lan966x_gck(hw) container_of(hw, struct lan966x_gck, hw)
static const struct clk_parent_data lan966x_gck_pdata[] = {
{ .fw_name = "cpu", },
{ .fw_name = "ddr", },
{ .fw_name = "sys", },
};
static struct clk_init_data init = {
.parent_data = lan966x_gck_pdata,
.num_parents = ARRAY_SIZE(lan966x_gck_pdata),
};
static void __iomem *base;
static int lan966x_gck_enable(struct clk_hw *hw)
{
struct lan966x_gck *gck = to_lan966x_gck(hw);
u32 val = readl(gck->reg);
val |= GCK_ENA;
writel(val, gck->reg);
return 0;
}
static void lan966x_gck_disable(struct clk_hw *hw)
{
struct lan966x_gck *gck = to_lan966x_gck(hw);
u32 val = readl(gck->reg);
val &= ~GCK_ENA;
writel(val, gck->reg);
}
static int lan966x_gck_set_rate(struct clk_hw *hw,
unsigned long rate,
unsigned long parent_rate)
{
struct lan966x_gck *gck = to_lan966x_gck(hw);
u32 div, val = readl(gck->reg);
if (rate == 0 || parent_rate == 0)
return -EINVAL;
/* Set Prescalar */
div = parent_rate / rate;
val &= ~GCK_PRESCALER;
val |= FIELD_PREP(GCK_PRESCALER, (div - 1));
writel(val, gck->reg);
return 0;
}
static long lan966x_gck_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
unsigned int div;
if (rate == 0 || *parent_rate == 0)
return -EINVAL;
if (rate >= *parent_rate)
return *parent_rate;
div = DIV_ROUND_CLOSEST(*parent_rate, rate);
return *parent_rate / div;
}
static unsigned long lan966x_gck_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct lan966x_gck *gck = to_lan966x_gck(hw);
u32 div, val = readl(gck->reg);
div = FIELD_GET(GCK_PRESCALER, val);
return parent_rate / (div + 1);
}
static int lan966x_gck_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct clk_hw *parent;
int i;
for (i = 0; i < clk_hw_get_num_parents(hw); ++i) {
parent = clk_hw_get_parent_by_index(hw, i);
if (!parent)
continue;
/* Allowed prescaler divider range is 0-255 */
if (clk_hw_get_rate(parent) / req->rate <= DIV_MAX) {
req->best_parent_hw = parent;
req->best_parent_rate = clk_hw_get_rate(parent);
return 0;
}
}
return -EINVAL;
}
static u8 lan966x_gck_get_parent(struct clk_hw *hw)
{
struct lan966x_gck *gck = to_lan966x_gck(hw);
u32 val = readl(gck->reg);
return FIELD_GET(GCK_SRC_SEL, val);
}
static int lan966x_gck_set_parent(struct clk_hw *hw, u8 index)
{
struct lan966x_gck *gck = to_lan966x_gck(hw);
u32 val = readl(gck->reg);
val &= ~GCK_SRC_SEL;
val |= FIELD_PREP(GCK_SRC_SEL, index);
writel(val, gck->reg);
return 0;
}
static const struct clk_ops lan966x_gck_ops = {
.enable = lan966x_gck_enable,
.disable = lan966x_gck_disable,
.set_rate = lan966x_gck_set_rate,
.round_rate = lan966x_gck_round_rate,
.recalc_rate = lan966x_gck_recalc_rate,
.determine_rate = lan966x_gck_determine_rate,
.set_parent = lan966x_gck_set_parent,
.get_parent = lan966x_gck_get_parent,
};
static struct clk_hw *lan966x_gck_clk_register(struct device *dev, int i)
{
struct lan966x_gck *priv;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return ERR_PTR(-ENOMEM);
priv->reg = base + (i * 4);
priv->hw.init = &init;
ret = devm_clk_hw_register(dev, &priv->hw);
if (ret)
return ERR_PTR(ret);
return &priv->hw;
};
static int lan966x_clk_probe(struct platform_device *pdev)
{
struct clk_hw_onecell_data *hw_data;
struct device *dev = &pdev->dev;
int i;
hw_data = devm_kzalloc(dev, struct_size(hw_data, hws, N_CLOCKS),
GFP_KERNEL);
if (!hw_data)
return -ENOMEM;
base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base))
return PTR_ERR(base);
init.ops = &lan966x_gck_ops;
hw_data->num = N_CLOCKS;
for (i = 0; i < N_CLOCKS; i++) {
init.name = clk_names[i];
hw_data->hws[i] = lan966x_gck_clk_register(dev, i);
if (IS_ERR(hw_data->hws[i])) {
dev_err(dev, "failed to register %s clock\n",
init.name);
return PTR_ERR(hw_data->hws[i]);
}
}
return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, hw_data);
}
static const struct of_device_id lan966x_clk_dt_ids[] = {
{ .compatible = "microchip,lan966x-gck", },
{ }
};
MODULE_DEVICE_TABLE(of, lan966x_clk_dt_ids);
static struct platform_driver lan966x_clk_driver = {
.probe = lan966x_clk_probe,
.driver = {
.name = "lan966x-clk",
.of_match_table = lan966x_clk_dt_ids,
},
};
builtin_platform_driver(lan966x_clk_driver);
MODULE_AUTHOR("Kavyasree Kotagiri <kavyasree.kotagiri@microchip.com>");
MODULE_DESCRIPTION("LAN966X clock driver");
MODULE_LICENSE("GPL v2");
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