linux/drivers/clk/x86/clk-st.c
Akshu Agrawal 421bf6a1f0 clk: x86: Add ST oscout platform clock
Stoney SoC provides oscout clock. This clock can support 25Mhz and
48Mhz of frequency.
The clock is available for general system use.

Signed-off-by: Akshu Agrawal <akshu.agrawal@amd.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-05-17 12:44:06 +02:00

78 lines
1.9 KiB
C

// SPDX-License-Identifier: MIT
/*
* clock framework for AMD Stoney based clocks
*
* Copyright 2018 Advanced Micro Devices, Inc.
*/
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/platform_data/clk-st.h>
#include <linux/platform_device.h>
/* Clock Driving Strength 2 register */
#define CLKDRVSTR2 0x28
/* Clock Control 1 register */
#define MISCCLKCNTL1 0x40
/* Auxiliary clock1 enable bit */
#define OSCCLKENB 2
/* 25Mhz auxiliary output clock freq bit */
#define OSCOUT1CLK25MHZ 16
#define ST_CLK_48M 0
#define ST_CLK_25M 1
#define ST_CLK_MUX 2
#define ST_CLK_GATE 3
#define ST_MAX_CLKS 4
static const char * const clk_oscout1_parents[] = { "clk48MHz", "clk25MHz" };
static struct clk_hw *hws[ST_MAX_CLKS];
static int st_clk_probe(struct platform_device *pdev)
{
struct st_clk_data *st_data;
st_data = dev_get_platdata(&pdev->dev);
if (!st_data || !st_data->base)
return -EINVAL;
hws[ST_CLK_48M] = clk_hw_register_fixed_rate(NULL, "clk48MHz", NULL, 0,
48000000);
hws[ST_CLK_25M] = clk_hw_register_fixed_rate(NULL, "clk25MHz", NULL, 0,
25000000);
hws[ST_CLK_MUX] = clk_hw_register_mux(NULL, "oscout1_mux",
clk_oscout1_parents, ARRAY_SIZE(clk_oscout1_parents),
0, st_data->base + CLKDRVSTR2, OSCOUT1CLK25MHZ, 3, 0, NULL);
clk_set_parent(hws[ST_CLK_MUX]->clk, hws[ST_CLK_25M]->clk);
hws[ST_CLK_GATE] = clk_hw_register_gate(NULL, "oscout1", "oscout1_mux",
0, st_data->base + MISCCLKCNTL1, OSCCLKENB,
CLK_GATE_SET_TO_DISABLE, NULL);
clk_hw_register_clkdev(hws[ST_CLK_GATE], "oscout1", NULL);
return 0;
}
static int st_clk_remove(struct platform_device *pdev)
{
int i;
for (i = 0; i < ST_MAX_CLKS; i++)
clk_hw_unregister(hws[i]);
return 0;
}
static struct platform_driver st_clk_driver = {
.driver = {
.name = "clk-st",
.suppress_bind_attrs = true,
},
.probe = st_clk_probe,
.remove = st_clk_remove,
};
builtin_platform_driver(st_clk_driver);