// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
*
* Authors:
* Serge Semin <[email protected]>
* Dmitry Dunaev <[email protected]>
*
* Baikal-T1 CCU PLL clocks driver
*/
#define pr_fmt(fmt) "bt1-ccu-pll: " fmt
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
#include <linux/slab.h>
#include <linux/clk-provider.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/ioport.h>
#include <linux/regmap.h>
#include <dt-bindings/clock/bt1-ccu.h>
#include "ccu-pll.h"
#define CCU_CPU_PLL_BASE 0x000
#define CCU_SATA_PLL_BASE 0x008
#define CCU_DDR_PLL_BASE 0x010
#define CCU_PCIE_PLL_BASE 0x018
#define CCU_ETH_PLL_BASE 0x020
#define CCU_PLL_INFO(_id, _name, _pname, _base, _flags, _features) \
{ \
.id = _id, \
.name = _name, \
.parent_name = _pname, \
.base = _base, \
.flags = _flags, \
.features = _features, \
}
#define CCU_PLL_NUM ARRAY_SIZE(pll_info)
struct ccu_pll_info {
unsigned int id;
const char *name;
const char *parent_name;
unsigned int base;
unsigned long flags;
unsigned long features;
};
/*
* Alas we have to mark all PLLs as critical. CPU and DDR PLLs are sources of
* CPU cores and DDR controller reference clocks, due to which they obviously
* shouldn't be ever gated. SATA and PCIe PLLs are the parents of APB-bus and
* DDR controller AXI-bus clocks. If they are gated the system will be
* unusable. Moreover disabling SATA and Ethernet PLLs causes automatic reset
* of the corresponding subsystems. So until we aren't ready to re-initialize
* all the devices consuming those PLLs, they will be marked as critical too.
*/
static const struct ccu_pll_info pll_info[] = {
CCU_PLL_INFO(CCU_CPU_PLL, "cpu_pll", "ref_clk", CCU_CPU_PLL_BASE,
CLK_IS_CRITICAL, CCU_PLL_BASIC),
CCU_PLL_INFO(CCU_SATA_PLL, "sata_pll", "ref_clk", CCU_SATA_PLL_BASE,
CLK_IS_CRITICAL | CLK_SET_RATE_GATE, 0),
CCU_PLL_INFO(CCU_DDR_PLL, "ddr_pll", "ref_clk", CCU_DDR_PLL_BASE,
CLK_IS_CRITICAL | CLK_SET_RATE_GATE, 0),
CCU_PLL_INFO(CCU_PCIE_PLL, "pcie_pll", "ref_clk", CCU_PCIE_PLL_BASE,
CLK_IS_CRITICAL, CCU_PLL_BASIC),
CCU_PLL_INFO(CCU_ETH_PLL, "eth_pll", "ref_clk", CCU_ETH_PLL_BASE,
CLK_IS_CRITICAL | CLK_SET_RATE_GATE, 0)
};
struct ccu_pll_data {
struct device_node *np;
struct regmap *sys_regs;
struct ccu_pll *plls[CCU_PLL_NUM];
};
static struct ccu_pll_data *pll_data;
static struct ccu_pll *ccu_pll_find_desc(struct ccu_pll_data *data,
unsigned int clk_id)
{
int idx;
for (idx = 0; idx < CCU_PLL_NUM; ++idx) {
if (pll_info[idx].id == clk_id)
return data->plls[idx];
}
return ERR_PTR(-EINVAL);
}
static struct ccu_pll_data *ccu_pll_create_data(struct device_node *np)
{
struct ccu_pll_data *data;
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return ERR_PTR(-ENOMEM);
data->np = np;
return data;
}
static void ccu_pll_free_data(struct ccu_pll_data *data)
{
kfree(data);
}
static int ccu_pll_find_sys_regs(struct ccu_pll_data *data)
{
data->sys_regs = syscon_node_to_regmap(data->np->parent);
if (IS_ERR(data->sys_regs)) {
pr_err("Failed to find syscon regs for '%s'\n",
of_node_full_name(data->np));
return PTR_ERR(data->sys_regs);
}
return 0;
}
static struct clk_hw *ccu_pll_of_clk_hw_get(struct of_phandle_args *clkspec,
void *priv)
{
struct ccu_pll_data *data = priv;
struct ccu_pll *pll;
unsigned int clk_id;
clk_id = clkspec->args[0];
pll = ccu_pll_find_desc(data, clk_id);
if (IS_ERR(pll)) {
if (pll != ERR_PTR(-EPROBE_DEFER))
pr_info("Invalid PLL clock ID %d specified\n", clk_id);
return ERR_CAST(pll);
}
return ccu_pll_get_clk_hw(pll);
}
static int ccu_pll_clk_register(struct ccu_pll_data *data, bool defer)
{
int idx, ret;
for (idx = 0; idx < CCU_PLL_NUM; ++idx) {
const struct ccu_pll_info *info = &pll_info[idx];
struct ccu_pll_init_data init = {0};
/* Defer non-basic PLLs allocation for the probe stage */
if (!!(info->features & CCU_PLL_BASIC) ^ defer) {
if (!data->plls[idx])
data->plls[idx] = ERR_PTR(-EPROBE_DEFER);
continue;
}
init.id = info->id;
init.name = info->name;
init.parent_name = info->parent_name;
init.base = info->base;
init.sys_regs = data->sys_regs;
init.np = data->np;
init.flags = info->flags;
init.features = info->features;
data->plls[idx] = ccu_pll_hw_register(&init);
if (IS_ERR(data->plls[idx])) {
ret = PTR_ERR(data->plls[idx]);
pr_err("Couldn't register PLL hw '%s'\n",
init.name);
goto err_hw_unregister;
}
}
return 0;
err_hw_unregister:
for (--idx; idx >= 0; --idx) {
if (!!(pll_info[idx].features & CCU_PLL_BASIC) ^ defer)
continue;
ccu_pll_hw_unregister(data->plls[idx]);
}
return ret;
}
static void ccu_pll_clk_unregister(struct ccu_pll_data *data, bool defer)
{
int idx;
/* Uninstall only the clocks registered on the specfied stage */
for (idx = 0; idx < CCU_PLL_NUM; ++idx) {
if (!!(pll_info[idx].features & CCU_PLL_BASIC) ^ defer)
continue;
ccu_pll_hw_unregister(data->plls[idx]);
}
}
static int ccu_pll_of_register(struct ccu_pll_data *data)
{
int ret;
ret = of_clk_add_hw_provider(data->np, ccu_pll_of_clk_hw_get, data);
if (ret) {
pr_err("Couldn't register PLL provider of '%s'\n",
of_node_full_name(data->np));
}
return ret;
}
static int ccu_pll_probe(struct platform_device *pdev)
{
struct ccu_pll_data *data = pll_data;
if (!data)
return -EINVAL;
return ccu_pll_clk_register(data, false);
}
static const struct of_device_id ccu_pll_of_match[] = {
{ .compatible = "baikal,bt1-ccu-pll" },
{ }
};
static struct platform_driver ccu_pll_driver = {
.probe = ccu_pll_probe,
.driver = {
.name = "clk-ccu-pll",
.of_match_table = ccu_pll_of_match,
.suppress_bind_attrs = true,
},
};
builtin_platform_driver(ccu_pll_driver);
static __init void ccu_pll_init(struct device_node *np)
{
struct ccu_pll_data *data;
int ret;
data = ccu_pll_create_data(np);
if (IS_ERR(data))
return;
ret = ccu_pll_find_sys_regs(data);
if (ret)
goto err_free_data;
ret = ccu_pll_clk_register(data, true);
if (ret)
goto err_free_data;
ret = ccu_pll_of_register(data);
if (ret)
goto err_clk_unregister;
pll_data = data;
return;
err_clk_unregister:
ccu_pll_clk_unregister(data, true);
err_free_data:
ccu_pll_free_data(data);
}
CLK_OF_DECLARE_DRIVER(ccu_pll, "baikal,bt1-ccu-pll", ccu_pll_init);
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