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/*
* Synopsys AXS10X SDP Generic PLL clock driver
*
* Copyright (C) 2017 Synopsys
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/device.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/of.h>
/* PLL registers addresses */
#define PLL_REG_IDIV 0x0
#define PLL_REG_FBDIV 0x4
#define PLL_REG_ODIV 0x8
/*
* Bit fields of the PLL IDIV/FBDIV/ODIV registers:
* ________________________________________________________________________
* |31 15| 14 | 13 | 12 |11 6|5 0|
* |-------RESRVED------|-NOUPDATE-|-BYPASS-|-EDGE-|--HIGHTIME--|--LOWTIME--|
* |____________________|__________|________|______|____________|___________|
*
* Following macros determine the way of access to these registers
* They should be set up only using the macros.
* reg should be an u32 variable.
*/
#define PLL_REG_GET_LOW(reg) \
(((reg) & (0x3F << 0)) >> 0)
#define PLL_REG_GET_HIGH(reg) \
(((reg) & (0x3F << 6)) >> 6)
#define PLL_REG_GET_EDGE(reg) \
(((reg) & (BIT(12))) ? 1 : 0)
#define PLL_REG_GET_BYPASS(reg) \
(((reg) & (BIT(13))) ? 1 : 0)
#define PLL_REG_GET_NOUPD(reg) \
(((reg) & (BIT(14))) ? 1 : 0)
#define PLL_REG_GET_PAD(reg) \
(((reg) & (0x1FFFF << 15)) >> 15)
#define PLL_REG_SET_LOW(reg, value) \
{ reg |= (((value) & 0x3F) << 0); }
#define PLL_REG_SET_HIGH(reg, value) \
{ reg |= (((value) & 0x3F) << 6); }
#define PLL_REG_SET_EDGE(reg, value) \
{ reg |= (((value) & 0x01) << 12); }
#define PLL_REG_SET_BYPASS(reg, value) \
{ reg |= (((value) & 0x01) << 13); }
#define PLL_REG_SET_NOUPD(reg, value) \
{ reg |= (((value) & 0x01) << 14); }
#define PLL_REG_SET_PAD(reg, value) \
{ reg |= (((value) & 0x1FFFF) << 15); }
#define PLL_LOCK BIT(0)
#define PLL_ERROR BIT(1)
#define PLL_MAX_LOCK_TIME 100 /* 100 us */
struct axs10x_pll_cfg {
u32 rate;
u32 idiv;
u32 fbdiv;
u32 odiv;
};
static const struct axs10x_pll_cfg arc_pll_cfg[] = {
{ 33333333, 1, 1, 1 },
{ 50000000, 1, 30, 20 },
{ 75000000, 2, 45, 10 },
{ 90000000, 2, 54, 10 },
{ 100000000, 1, 30, 10 },
{ 125000000, 2, 45, 6 },
{}
};
static const struct axs10x_pll_cfg pgu_pll_cfg[] = {
{ 25200000, 1, 84, 90 },
{ 50000000, 1, 100, 54 },
{ 74250000, 1, 44, 16 },
{}
};
struct axs10x_pll_clk {
struct clk_hw hw;
void __iomem *base;
void __iomem *lock;
const struct axs10x_pll_cfg *pll_cfg;
struct device *dev;
};
static inline void axs10x_pll_write(struct axs10x_pll_clk *clk, u32 reg,
u32 val)
{
iowrite32(val, clk->base + reg);
}
static inline u32 axs10x_pll_read(struct axs10x_pll_clk *clk, u32 reg)
{
return ioread32(clk->base + reg);
}
static inline struct axs10x_pll_clk *to_axs10x_pll_clk(struct clk_hw *hw)
{
return container_of(hw, struct axs10x_pll_clk, hw);
}
static inline u32 axs10x_div_get_value(u32 reg)
{
if (PLL_REG_GET_BYPASS(reg))
return 1;
return PLL_REG_GET_HIGH(reg) + PLL_REG_GET_LOW(reg);
}
static inline u32 axs10x_encode_div(unsigned int id, int upd)
{
u32 div = 0;
PLL_REG_SET_LOW(div, (id % 2 == 0) ? id >> 1 : (id >> 1) + 1);
PLL_REG_SET_HIGH(div, id >> 1);
PLL_REG_SET_EDGE(div, id % 2);
PLL_REG_SET_BYPASS(div, id == 1 ? 1 : 0);
PLL_REG_SET_NOUPD(div, upd == 0 ? 1 : 0);
return div;
}
static unsigned long axs10x_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
u64 rate;
u32 idiv, fbdiv, odiv;
struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
idiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_IDIV));
fbdiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_FBDIV));
odiv = axs10x_div_get_value(axs10x_pll_read(clk, PLL_REG_ODIV));
rate = (u64)parent_rate * fbdiv;
do_div(rate, idiv * odiv);
return rate;
}
static long axs10x_pll_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
int i;
long best_rate;
struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
if (pll_cfg[0].rate == 0)
return -EINVAL;
best_rate = pll_cfg[0].rate;
for (i = 1; pll_cfg[i].rate != 0; i++) {
if (abs(rate - pll_cfg[i].rate) < abs(rate - best_rate))
best_rate = pll_cfg[i].rate;
}
return best_rate;
}
static int axs10x_pll_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
int i;
struct axs10x_pll_clk *clk = to_axs10x_pll_clk(hw);
const struct axs10x_pll_cfg *pll_cfg = clk->pll_cfg;
for (i = 0; pll_cfg[i].rate != 0; i++) {
if (pll_cfg[i].rate == rate) {
axs10x_pll_write(clk, PLL_REG_IDIV,
axs10x_encode_div(pll_cfg[i].idiv, 0));
axs10x_pll_write(clk, PLL_REG_FBDIV,
axs10x_encode_div(pll_cfg[i].fbdiv, 0));
axs10x_pll_write(clk, PLL_REG_ODIV,
axs10x_encode_div(pll_cfg[i].odiv, 1));
/*
* Wait until CGU relocks and check error status.
* If after timeout CGU is unlocked yet return error
*/
udelay(PLL_MAX_LOCK_TIME);
if (!(ioread32(clk->lock) & PLL_LOCK))
return -ETIMEDOUT;
if (ioread32(clk->lock) & PLL_ERROR)
return -EINVAL;
return 0;
}
}
dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
parent_rate);
return -EINVAL;
}
static const struct clk_ops axs10x_pll_ops = {
.recalc_rate = axs10x_pll_recalc_rate,
.round_rate = axs10x_pll_round_rate,
.set_rate = axs10x_pll_set_rate,
};
static int axs10x_pll_clk_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const char *parent_name;
struct axs10x_pll_clk *pll_clk;
struct resource *mem;
struct clk_init_data init = { };
int ret;
pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
if (!pll_clk)
return -ENOMEM;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
pll_clk->base = devm_ioremap_resource(dev, mem);
if (IS_ERR(pll_clk->base))
return PTR_ERR(pll_clk->base);
mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
pll_clk->lock = devm_ioremap_resource(dev, mem);
if (IS_ERR(pll_clk->lock))
return PTR_ERR(pll_clk->lock);
init.name = dev->of_node->name;
init.ops = &axs10x_pll_ops;
parent_name = of_clk_get_parent_name(dev->of_node, 0);
init.parent_names = &parent_name;
init.num_parents = 1;
pll_clk->hw.init = &init;
pll_clk->dev = dev;
pll_clk->pll_cfg = of_device_get_match_data(dev);
if (!pll_clk->pll_cfg) {
dev_err(dev, "No OF match data provided\n");
return -EINVAL;
}
ret = devm_clk_hw_register(dev, &pll_clk->hw);
if (ret) {
dev_err(dev, "failed to register %s clock\n", init.name);
return ret;
}
return of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
&pll_clk->hw);
}
static int axs10x_pll_clk_remove(struct platform_device *pdev)
{
of_clk_del_provider(pdev->dev.of_node);
return 0;
}
static void __init of_axs10x_pll_clk_setup(struct device_node *node)
{
const char *parent_name;
struct axs10x_pll_clk *pll_clk;
struct clk_init_data init = { };
int ret;
pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
if (!pll_clk)
return;
pll_clk->base = of_iomap(node, 0);
if (!pll_clk->base) {
pr_err("failed to map pll div registers\n");
goto err_free_pll_clk;
}
pll_clk->lock = of_iomap(node, 1);
if (!pll_clk->lock) {
pr_err("failed to map pll lock register\n");
goto err_unmap_base;
}
init.name = node->name;
init.ops = &axs10x_pll_ops;
parent_name = of_clk_get_parent_name(node, 0);
init.parent_names = &parent_name;
init.num_parents = parent_name ? 1 : 0;
pll_clk->hw.init = &init;
pll_clk->pll_cfg = arc_pll_cfg;
ret = clk_hw_register(NULL, &pll_clk->hw);
if (ret) {
pr_err("failed to register %pOFn clock\n", node);
goto err_unmap_lock;
}
ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll_clk->hw);
if (ret) {
pr_err("failed to add hw provider for %pOFn clock\n", node);
goto err_unregister_clk;
}
return;
err_unregister_clk:
clk_hw_unregister(&pll_clk->hw);
err_unmap_lock:
iounmap(pll_clk->lock);
err_unmap_base:
iounmap(pll_clk->base);
err_free_pll_clk:
kfree(pll_clk);
}
CLK_OF_DECLARE(axs10x_pll_clock, "snps,axs10x-arc-pll-clock",
of_axs10x_pll_clk_setup);
static const struct of_device_id axs10x_pll_clk_id[] = {
{ .compatible = "snps,axs10x-pgu-pll-clock", .data = &pgu_pll_cfg},
{ }
};
MODULE_DEVICE_TABLE(of, axs10x_pll_clk_id);
static struct platform_driver axs10x_pll_clk_driver = {
.driver = {
.name = "axs10x-pll-clock",
.of_match_table = axs10x_pll_clk_id,
},
.probe = axs10x_pll_clk_probe,
.remove = axs10x_pll_clk_remove,
};
builtin_platform_driver(axs10x_pll_clk_driver);
MODULE_AUTHOR("Vlad Zakharov <vzakhar@synopsys.com>");
MODULE_DESCRIPTION("Synopsys AXS10X SDP Generic PLL Clock Driver");
MODULE_LICENSE("GPL v2");