u-boot/drivers/clk/at91/clk-generic.c
Claudiu Beznea 36a9630fcb clk: at91: clk-generic: add driver compatible with ccf
Add clk-generic driver compatible with common clock framework.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
2020-09-22 11:27:18 +03:00

202 lines
4.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Generic clock support for AT91 architectures.
*
* Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries
*
* Author: Claudiu Beznea <claudiu.beznea@microchip.com>
*
* Based on drivers/clk/at91/clk-generated.c from Linux.
*/
#include <common.h>
#include <clk-uclass.h>
#include <dm.h>
#include <linux/io.h>
#include <linux/clk-provider.h>
#include <linux/clk/at91_pmc.h>
#include "pmc.h"
#define UBOOT_DM_CLK_AT91_GCK "at91-gck-clk"
#define GENERATED_MAX_DIV 255
struct clk_gck {
void __iomem *base;
const u32 *clk_mux_table;
const u32 *mux_table;
const struct clk_pcr_layout *layout;
struct clk_range range;
struct clk clk;
u32 num_parents;
u32 id;
};
#define to_clk_gck(_c) container_of(_c, struct clk_gck, clk)
static int clk_gck_enable(struct clk *clk)
{
struct clk_gck *gck = to_clk_gck(clk);
pmc_write(gck->base, gck->layout->offset,
(gck->id & gck->layout->pid_mask));
pmc_update_bits(gck->base, gck->layout->offset,
gck->layout->cmd | AT91_PMC_PCR_GCKEN,
gck->layout->cmd | AT91_PMC_PCR_GCKEN);
return 0;
}
static int clk_gck_disable(struct clk *clk)
{
struct clk_gck *gck = to_clk_gck(clk);
pmc_write(gck->base, gck->layout->offset,
(gck->id & gck->layout->pid_mask));
pmc_update_bits(gck->base, gck->layout->offset,
gck->layout->cmd | AT91_PMC_PCR_GCKEN,
gck->layout->cmd);
return 0;
}
static int clk_gck_set_parent(struct clk *clk, struct clk *parent)
{
struct clk_gck *gck = to_clk_gck(clk);
int index;
index = at91_clk_mux_val_to_index(gck->clk_mux_table, gck->num_parents,
parent->id);
if (index < 0)
return index;
index = at91_clk_mux_index_to_val(gck->mux_table, gck->num_parents,
index);
if (index < 0)
return index;
pmc_write(gck->base, gck->layout->offset,
(gck->id & gck->layout->pid_mask));
pmc_update_bits(gck->base, gck->layout->offset,
gck->layout->gckcss_mask | gck->layout->cmd,
(index << (ffs(gck->layout->gckcss_mask) - 1)) |
gck->layout->cmd);
return 0;
}
static ulong clk_gck_set_rate(struct clk *clk, ulong rate)
{
struct clk_gck *gck = to_clk_gck(clk);
ulong parent_rate = clk_get_parent_rate(clk);
u32 div;
if (!rate || !parent_rate)
return 0;
if (gck->range.max && rate > gck->range.max)
return 0;
div = DIV_ROUND_CLOSEST(parent_rate, rate);
if (div > GENERATED_MAX_DIV + 1 || !div)
return 0;
pmc_write(gck->base, gck->layout->offset,
(gck->id & gck->layout->pid_mask));
pmc_update_bits(gck->base, gck->layout->offset,
AT91_PMC_PCR_GCKDIV_MASK | gck->layout->cmd,
((div - 1) << (ffs(AT91_PMC_PCR_GCKDIV_MASK) - 1)) |
gck->layout->cmd);
return parent_rate / div;
}
static ulong clk_gck_get_rate(struct clk *clk)
{
struct clk_gck *gck = to_clk_gck(clk);
ulong parent_rate = clk_get_parent_rate(clk);
u32 val, div;
if (!parent_rate)
return 0;
pmc_write(gck->base, gck->layout->offset,
(gck->id & gck->layout->pid_mask));
pmc_read(gck->base, gck->layout->offset, &val);
div = (val & AT91_PMC_PCR_GCKDIV_MASK) >>
(ffs(AT91_PMC_PCR_GCKDIV_MASK) - 1);
return parent_rate / (div + 1);
}
static const struct clk_ops gck_ops = {
.enable = clk_gck_enable,
.disable = clk_gck_disable,
.set_parent = clk_gck_set_parent,
.set_rate = clk_gck_set_rate,
.get_rate = clk_gck_get_rate,
};
struct clk *
at91_clk_register_generic(void __iomem *base,
const struct clk_pcr_layout *layout,
const char *name, const char * const *parent_names,
const u32 *clk_mux_table, const u32 *mux_table,
u8 num_parents, u8 id,
const struct clk_range *range)
{
struct clk_gck *gck;
struct clk *clk;
int ret, index;
u32 val;
if (!base || !layout || !name || !parent_names || !num_parents ||
!clk_mux_table || !mux_table || !range)
return ERR_PTR(-EINVAL);
gck = kzalloc(sizeof(*gck), GFP_KERNEL);
if (!gck)
return ERR_PTR(-ENOMEM);
gck->id = id;
gck->base = base;
gck->range = *range;
gck->layout = layout;
gck->clk_mux_table = clk_mux_table;
gck->mux_table = mux_table;
gck->num_parents = num_parents;
clk = &gck->clk;
clk->flags = CLK_GET_RATE_NOCACHE;
pmc_write(gck->base, gck->layout->offset,
(gck->id & gck->layout->pid_mask));
pmc_read(gck->base, gck->layout->offset, &val);
val = (val & gck->layout->gckcss_mask) >>
(ffs(gck->layout->gckcss_mask) - 1);
index = at91_clk_mux_val_to_index(gck->mux_table, gck->num_parents,
val);
if (index < 0) {
kfree(gck);
return ERR_PTR(index);
}
ret = clk_register(clk, UBOOT_DM_CLK_AT91_GCK, name,
parent_names[index]);
if (ret) {
kfree(gck);
clk = ERR_PTR(ret);
}
return clk;
}
U_BOOT_DRIVER(at91_gck_clk) = {
.name = UBOOT_DM_CLK_AT91_GCK,
.id = UCLASS_CLK,
.ops = &gck_ops,
.flags = DM_FLAG_PRE_RELOC,
};