linuxdebug/drivers/clk/renesas/rcar-gen4-cpg.c

311 lines
7.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* R-Car Gen4 Clock Pulse Generator
*
* Copyright (C) 2021 Renesas Electronics Corp.
*
* Based on rcar-gen3-cpg.c
*
* Copyright (C) 2015-2018 Glider bvba
* Copyright (C) 2019 Renesas Electronics Corp.
*/
#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "renesas-cpg-mssr.h"
#include "rcar-gen4-cpg.h"
#include "rcar-cpg-lib.h"
static const struct rcar_gen4_cpg_pll_config *cpg_pll_config __initdata;
static unsigned int cpg_clk_extalr __initdata;
static u32 cpg_mode __initdata;
/*
* Z0 Clock & Z1 Clock
*/
#define CPG_FRQCRB 0x00000804
#define CPG_FRQCRB_KICK BIT(31)
#define CPG_FRQCRC 0x00000808
struct cpg_z_clk {
struct clk_hw hw;
void __iomem *reg;
void __iomem *kick_reg;
unsigned long max_rate; /* Maximum rate for normal mode */
unsigned int fixed_div;
u32 mask;
};
#define to_z_clk(_hw) container_of(_hw, struct cpg_z_clk, hw)
static unsigned long cpg_z_clk_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct cpg_z_clk *zclk = to_z_clk(hw);
unsigned int mult;
u32 val;
val = readl(zclk->reg) & zclk->mask;
mult = 32 - (val >> __ffs(zclk->mask));
return DIV_ROUND_CLOSEST_ULL((u64)parent_rate * mult,
32 * zclk->fixed_div);
}
static int cpg_z_clk_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct cpg_z_clk *zclk = to_z_clk(hw);
unsigned int min_mult, max_mult, mult;
unsigned long rate, prate;
rate = min(req->rate, req->max_rate);
if (rate <= zclk->max_rate) {
/* Set parent rate to initial value for normal modes */
prate = zclk->max_rate;
} else {
/* Set increased parent rate for boost modes */
prate = rate;
}
req->best_parent_rate = clk_hw_round_rate(clk_hw_get_parent(hw),
prate * zclk->fixed_div);
prate = req->best_parent_rate / zclk->fixed_div;
min_mult = max(div64_ul(req->min_rate * 32ULL, prate), 1ULL);
max_mult = min(div64_ul(req->max_rate * 32ULL, prate), 32ULL);
if (max_mult < min_mult)
return -EINVAL;
mult = DIV_ROUND_CLOSEST_ULL(rate * 32ULL, prate);
mult = clamp(mult, min_mult, max_mult);
req->rate = DIV_ROUND_CLOSEST_ULL((u64)prate * mult, 32);
return 0;
}
static int cpg_z_clk_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct cpg_z_clk *zclk = to_z_clk(hw);
unsigned int mult;
unsigned int i;
mult = DIV64_U64_ROUND_CLOSEST(rate * 32ULL * zclk->fixed_div,
parent_rate);
mult = clamp(mult, 1U, 32U);
if (readl(zclk->kick_reg) & CPG_FRQCRB_KICK)
return -EBUSY;
cpg_reg_modify(zclk->reg, zclk->mask, (32 - mult) << __ffs(zclk->mask));
/*
* Set KICK bit in FRQCRB to update hardware setting and wait for
* clock change completion.
*/
cpg_reg_modify(zclk->kick_reg, 0, CPG_FRQCRB_KICK);
/*
* Note: There is no HW information about the worst case latency.
*
* Using experimental measurements, it seems that no more than
* ~10 iterations are needed, independently of the CPU rate.
* Since this value might be dependent on external xtal rate, pll1
* rate or even the other emulation clocks rate, use 1000 as a
* "super" safe value.
*/
for (i = 1000; i; i--) {
if (!(readl(zclk->kick_reg) & CPG_FRQCRB_KICK))
return 0;
cpu_relax();
}
return -ETIMEDOUT;
}
static const struct clk_ops cpg_z_clk_ops = {
.recalc_rate = cpg_z_clk_recalc_rate,
.determine_rate = cpg_z_clk_determine_rate,
.set_rate = cpg_z_clk_set_rate,
};
static struct clk * __init cpg_z_clk_register(const char *name,
const char *parent_name,
void __iomem *reg,
unsigned int div,
unsigned int offset)
{
struct clk_init_data init = {};
struct cpg_z_clk *zclk;
struct clk *clk;
zclk = kzalloc(sizeof(*zclk), GFP_KERNEL);
if (!zclk)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &cpg_z_clk_ops;
init.flags = CLK_SET_RATE_PARENT;
init.parent_names = &parent_name;
init.num_parents = 1;
zclk->reg = reg + CPG_FRQCRC;
zclk->kick_reg = reg + CPG_FRQCRB;
zclk->hw.init = &init;
zclk->mask = GENMASK(offset + 4, offset);
zclk->fixed_div = div; /* PLLVCO x 1/div x SYS-CPU divider */
clk = clk_register(NULL, &zclk->hw);
if (IS_ERR(clk)) {
kfree(zclk);
return clk;
}
zclk->max_rate = clk_hw_get_rate(clk_hw_get_parent(&zclk->hw)) /
zclk->fixed_div;
return clk;
}
/*
* RPC Clocks
*/
static const struct clk_div_table cpg_rpcsrc_div_table[] = {
{ 0, 4 }, { 1, 6 }, { 2, 5 }, { 3, 6 }, { 0, 0 },
};
struct clk * __init rcar_gen4_cpg_clk_register(struct device *dev,
const struct cpg_core_clk *core, const struct cpg_mssr_info *info,
struct clk **clks, void __iomem *base,
struct raw_notifier_head *notifiers)
{
const struct clk *parent;
unsigned int mult = 1;
unsigned int div = 1;
u32 value;
parent = clks[core->parent & 0xffff]; /* some types use high bits */
if (IS_ERR(parent))
return ERR_CAST(parent);
switch (core->type) {
case CLK_TYPE_GEN4_MAIN:
div = cpg_pll_config->extal_div;
break;
case CLK_TYPE_GEN4_PLL1:
mult = cpg_pll_config->pll1_mult;
div = cpg_pll_config->pll1_div;
break;
case CLK_TYPE_GEN4_PLL2:
mult = cpg_pll_config->pll2_mult;
div = cpg_pll_config->pll2_div;
break;
case CLK_TYPE_GEN4_PLL3:
mult = cpg_pll_config->pll3_mult;
div = cpg_pll_config->pll3_div;
break;
case CLK_TYPE_GEN4_PLL4:
mult = cpg_pll_config->pll4_mult;
div = cpg_pll_config->pll4_div;
break;
case CLK_TYPE_GEN4_PLL5:
mult = cpg_pll_config->pll5_mult;
div = cpg_pll_config->pll5_div;
break;
case CLK_TYPE_GEN4_PLL6:
mult = cpg_pll_config->pll6_mult;
div = cpg_pll_config->pll6_div;
break;
case CLK_TYPE_GEN4_PLL2X_3X:
value = readl(base + core->offset);
mult = (((value >> 24) & 0x7f) + 1) * 2;
break;
case CLK_TYPE_GEN4_Z:
return cpg_z_clk_register(core->name, __clk_get_name(parent),
base, core->div, core->offset);
case CLK_TYPE_GEN4_SDSRC:
div = ((readl(base + SD0CKCR1) >> 29) & 0x03) + 4;
break;
case CLK_TYPE_GEN4_SDH:
return cpg_sdh_clk_register(core->name, base + core->offset,
__clk_get_name(parent), notifiers);
case CLK_TYPE_GEN4_SD:
return cpg_sd_clk_register(core->name, base + core->offset,
__clk_get_name(parent));
case CLK_TYPE_GEN4_MDSEL:
/*
* Clock selectable between two parents and two fixed dividers
* using a mode pin
*/
if (cpg_mode & BIT(core->offset)) {
div = core->div & 0xffff;
} else {
parent = clks[core->parent >> 16];
if (IS_ERR(parent))
return ERR_CAST(parent);
div = core->div >> 16;
}
mult = 1;
break;
case CLK_TYPE_GEN4_OSC:
/*
* Clock combining OSC EXTAL predivider and a fixed divider
*/
div = cpg_pll_config->osc_prediv * core->div;
break;
case CLK_TYPE_GEN4_RPCSRC:
return clk_register_divider_table(NULL, core->name,
__clk_get_name(parent), 0,
base + CPG_RPCCKCR, 3, 2, 0,
cpg_rpcsrc_div_table,
&cpg_lock);
case CLK_TYPE_GEN4_RPC:
return cpg_rpc_clk_register(core->name, base + CPG_RPCCKCR,
__clk_get_name(parent), notifiers);
case CLK_TYPE_GEN4_RPCD2:
return cpg_rpcd2_clk_register(core->name, base + CPG_RPCCKCR,
__clk_get_name(parent));
default:
return ERR_PTR(-EINVAL);
}
return clk_register_fixed_factor(NULL, core->name,
__clk_get_name(parent), 0, mult, div);
}
int __init rcar_gen4_cpg_init(const struct rcar_gen4_cpg_pll_config *config,
unsigned int clk_extalr, u32 mode)
{
cpg_pll_config = config;
cpg_clk_extalr = clk_extalr;
cpg_mode = mode;
spin_lock_init(&cpg_lock);
return 0;
}