linux/drivers/clk/mvebu/armada-37xx-tbg.c
Gregory CLEMENT 96265523ac clk: mvebu Add the time base generator clocks for Armada 3700
These clocks are children of the xtal clock and each one can be selected
as a source for the peripheral clocks.

According to the datasheet it should be possible to modify their rate,
but currently it is not supported.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
2016-08-15 14:10:20 -07:00

159 lines
3.8 KiB
C

/*
* Marvell Armada 37xx SoC Time Base Generator clocks
*
* Copyright (C) 2016 Marvell
*
* Gregory CLEMENT <gregory.clement@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2 or later. This program is licensed "as is"
* without any warranty of any kind, whether express or implied.
*/
#include <linux/clk-provider.h>
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#define NUM_TBG 4
#define TBG_CTRL0 0x4
#define TBG_CTRL1 0x8
#define TBG_CTRL7 0x20
#define TBG_CTRL8 0x30
#define TBG_DIV_MASK 0x1FF
#define TBG_A_REFDIV 0
#define TBG_B_REFDIV 16
#define TBG_A_FBDIV 2
#define TBG_B_FBDIV 18
#define TBG_A_VCODIV_SE 0
#define TBG_B_VCODIV_SE 16
#define TBG_A_VCODIV_DIFF 1
#define TBG_B_VCODIV_DIFF 17
struct tbg_def {
char *name;
u32 refdiv_offset;
u32 fbdiv_offset;
u32 vcodiv_reg;
u32 vcodiv_offset;
};
static const struct tbg_def tbg[NUM_TBG] = {
{"TBG-A-P", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL8, TBG_A_VCODIV_DIFF},
{"TBG-B-P", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL8, TBG_B_VCODIV_DIFF},
{"TBG-A-S", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL1, TBG_A_VCODIV_SE},
{"TBG-B-S", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL1, TBG_B_VCODIV_SE},
};
static unsigned int tbg_get_mult(void __iomem *reg, const struct tbg_def *ptbg)
{
u32 val;
val = readl(reg + TBG_CTRL0);
return ((val >> ptbg->fbdiv_offset) & TBG_DIV_MASK) << 2;
}
static unsigned int tbg_get_div(void __iomem *reg, const struct tbg_def *ptbg)
{
u32 val;
unsigned int div;
val = readl(reg + TBG_CTRL7);
div = (val >> ptbg->refdiv_offset) & TBG_DIV_MASK;
if (div == 0)
div = 1;
val = readl(reg + ptbg->vcodiv_reg);
div *= 1 << ((val >> ptbg->vcodiv_offset) & TBG_DIV_MASK);
return div;
}
static int armada_3700_tbg_clock_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct clk_hw_onecell_data *hw_tbg_data;
struct device *dev = &pdev->dev;
const char *parent_name;
struct resource *res;
struct clk *parent;
void __iomem *reg;
int i, ret;
hw_tbg_data = devm_kzalloc(&pdev->dev, sizeof(*hw_tbg_data)
+ sizeof(*hw_tbg_data->hws) * NUM_TBG,
GFP_KERNEL);
if (!hw_tbg_data)
return -ENOMEM;
hw_tbg_data->num = NUM_TBG;
platform_set_drvdata(pdev, hw_tbg_data);
parent = devm_clk_get(dev, NULL);
if (IS_ERR(parent)) {
dev_err(dev, "Could get the clock parent\n");
return -EINVAL;
}
parent_name = __clk_get_name(parent);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
reg = devm_ioremap_resource(dev, res);
if (IS_ERR(reg))
return PTR_ERR(reg);
for (i = 0; i < NUM_TBG; i++) {
const char *name;
unsigned int mult, div;
name = tbg[i].name;
mult = tbg_get_mult(reg, &tbg[i]);
div = tbg_get_div(reg, &tbg[i]);
hw_tbg_data->hws[i] = clk_hw_register_fixed_factor(NULL, name,
parent_name, 0, mult, div);
if (IS_ERR(hw_tbg_data->hws[i]))
dev_err(dev, "Can't register TBG clock %s\n", name);
}
ret = of_clk_add_hw_provider(np, of_clk_hw_onecell_get, hw_tbg_data);
return ret;
}
static int armada_3700_tbg_clock_remove(struct platform_device *pdev)
{
int i;
struct clk_hw_onecell_data *hw_tbg_data = platform_get_drvdata(pdev);
of_clk_del_provider(pdev->dev.of_node);
for (i = 0; i < hw_tbg_data->num; i++)
clk_hw_unregister_fixed_factor(hw_tbg_data->hws[i]);
return 0;
}
static const struct of_device_id armada_3700_tbg_clock_of_match[] = {
{ .compatible = "marvell,armada-3700-tbg-clock", },
{ }
};
static struct platform_driver armada_3700_tbg_clock_driver = {
.probe = armada_3700_tbg_clock_probe,
.remove = armada_3700_tbg_clock_remove,
.driver = {
.name = "marvell-armada-3700-tbg-clock",
.of_match_table = armada_3700_tbg_clock_of_match,
},
};
builtin_platform_driver(armada_3700_tbg_clock_driver);