armada-37xx-tbg.c

  1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Marvell Armada 37xx SoC Time Base Generator clocks
  4 *
  5 * Copyright (C) 2016 Marvell
  6 *
  7 * Gregory CLEMENT <gregory.clement@free-electrons.com>
  8 */
  9
 10#include <linux/clk-provider.h>
 11#include <linux/clk.h>
 12#include <linux/io.h>
 13#include <linux/of.h>
 14#include <linux/of_address.h>
 15#include <linux/platform_device.h>
 16#include <linux/slab.h>
 17
 18#define NUM_TBG	    4
 19
 20#define TBG_CTRL0		0x4
 21#define TBG_CTRL1		0x8
 22#define TBG_CTRL7		0x20
 23#define TBG_CTRL8		0x30
 24
 25#define TBG_DIV_MASK		0x1FF
 26
 27#define TBG_A_REFDIV		0
 28#define TBG_B_REFDIV		16
 29
 30#define TBG_A_FBDIV		2
 31#define TBG_B_FBDIV		18
 32
 33#define TBG_A_VCODIV_SE		0
 34#define TBG_B_VCODIV_SE		16
 35
 36#define TBG_A_VCODIV_DIFF	1
 37#define TBG_B_VCODIV_DIFF	17
 38
 39struct tbg_def {
 40	char *name;
 41	u32 refdiv_offset;
 42	u32 fbdiv_offset;
 43	u32 vcodiv_reg;
 44	u32 vcodiv_offset;
 45};
 46
 47static const struct tbg_def tbg[NUM_TBG] = {
 48	{"TBG-A-P", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL8, TBG_A_VCODIV_DIFF},
 49	{"TBG-B-P", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL8, TBG_B_VCODIV_DIFF},
 50	{"TBG-A-S", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL1, TBG_A_VCODIV_SE},
 51	{"TBG-B-S", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL1, TBG_B_VCODIV_SE},
 52};
 53
 54static unsigned int tbg_get_mult(void __iomem *reg, const struct tbg_def *ptbg)
 55{
 56	u32 val;
 57
 58	val = readl(reg + TBG_CTRL0);
 59
 60	return ((val >> ptbg->fbdiv_offset) & TBG_DIV_MASK) << 2;
 61}
 62
 63static unsigned int tbg_get_div(void __iomem *reg, const struct tbg_def *ptbg)
 64{
 65	u32 val;
 66	unsigned int div;
 67
 68	val = readl(reg + TBG_CTRL7);
 69
 70	div = (val >> ptbg->refdiv_offset) & TBG_DIV_MASK;
 71	if (div == 0)
 72		div = 1;
 73	val = readl(reg + ptbg->vcodiv_reg);
 74
 75	div *= 1 << ((val >>  ptbg->vcodiv_offset) & TBG_DIV_MASK);
 76
 77	return div;
 78}
 79
 80
 81static int armada_3700_tbg_clock_probe(struct platform_device *pdev)
 82{
 83	struct device_node *np = pdev->dev.of_node;
 84	struct clk_hw_onecell_data *hw_tbg_data;
 85	struct device *dev = &pdev->dev;
 86	const char *parent_name;
 87	struct clk *parent;
 88	void __iomem *reg;
 89	int i;
 90
 91	hw_tbg_data = devm_kzalloc(&pdev->dev,
 92				   struct_size(hw_tbg_data, hws, NUM_TBG),
 93				   GFP_KERNEL);
 94	if (!hw_tbg_data)
 95		return -ENOMEM;
 96	hw_tbg_data->num = NUM_TBG;
 97	platform_set_drvdata(pdev, hw_tbg_data);
 98
 99	parent = clk_get(dev, NULL);
100	if (IS_ERR(parent)) {
101		dev_err(dev, "Could get the clock parent\n");
102		return -EINVAL;
103	}
104	parent_name = __clk_get_name(parent);
105	clk_put(parent);
106
107	reg = devm_platform_ioremap_resource(pdev, 0);
108	if (IS_ERR(reg))
109		return PTR_ERR(reg);
110
111	for (i = 0; i < NUM_TBG; i++) {
112		const char *name;
113		unsigned int mult, div;
114
115		name = tbg[i].name;
116		mult = tbg_get_mult(reg, &tbg[i]);
117		div = tbg_get_div(reg, &tbg[i]);
118		hw_tbg_data->hws[i] = clk_hw_register_fixed_factor(NULL, name,
119						parent_name, 0, mult, div);
120		if (IS_ERR(hw_tbg_data->hws[i]))
121			dev_err(dev, "Can't register TBG clock %s\n", name);
122	}
123
124	return of_clk_add_hw_provider(np, of_clk_hw_onecell_get, hw_tbg_data);
125}
126
127static void armada_3700_tbg_clock_remove(struct platform_device *pdev)
128{
129	int i;
130	struct clk_hw_onecell_data *hw_tbg_data = platform_get_drvdata(pdev);
131
132	of_clk_del_provider(pdev->dev.of_node);
133	for (i = 0; i < hw_tbg_data->num; i++)
134		clk_hw_unregister_fixed_factor(hw_tbg_data->hws[i]);
135}
136
137static const struct of_device_id armada_3700_tbg_clock_of_match[] = {
138	{ .compatible = "marvell,armada-3700-tbg-clock", },
139	{ }
140};
141
142static struct platform_driver armada_3700_tbg_clock_driver = {
143	.probe = armada_3700_tbg_clock_probe,
144	.remove = armada_3700_tbg_clock_remove,
145	.driver		= {
146		.name	= "marvell-armada-3700-tbg-clock",
147		.of_match_table = armada_3700_tbg_clock_of_match,
148	},
149};
150
151builtin_platform_driver(armada_3700_tbg_clock_driver);