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  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *  Copyright 2011-2012 Calxeda, Inc.
  4 *  Copyright (C) 2012-2013 Altera Corporation <www.altera.com>
  5 *
  6 * Based from clk-highbank.c
  7 */
  8#include <linux/slab.h>
  9#include <linux/clk-provider.h>
 10#include <linux/io.h>
 11#include <linux/mfd/syscon.h>
 12#include <linux/of.h>
 13#include <linux/regmap.h>
 14
 15#include "clk.h"
 16
 17#define SOCFPGA_L4_MP_CLK		"l4_mp_clk"
 18#define SOCFPGA_L4_SP_CLK		"l4_sp_clk"
 19#define SOCFPGA_NAND_CLK		"nand_clk"
 20#define SOCFPGA_NAND_X_CLK		"nand_x_clk"
 21#define SOCFPGA_MMC_CLK			"sdmmc_clk"
 22#define SOCFPGA_GPIO_DB_CLK_OFFSET	0xA8
 23
 24#define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
 25
 26/* SDMMC Group for System Manager defines */
 27#define SYSMGR_SDMMCGRP_CTRL_OFFSET    0x108
 28
 29static u8 socfpga_clk_get_parent(struct clk_hw *hwclk)
 30{
 31	u32 l4_src;
 32	u32 perpll_src;
 33	const char *name = clk_hw_get_name(hwclk);
 34
 35	if (streq(name, SOCFPGA_L4_MP_CLK)) {
 36		l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
 37		return l4_src & 0x1;
 38	}
 39	if (streq(name, SOCFPGA_L4_SP_CLK)) {
 40		l4_src = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
 41		return !!(l4_src & 2);
 42	}
 43
 44	perpll_src = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
 45	if (streq(name, SOCFPGA_MMC_CLK))
 46		return perpll_src & 0x3;
 47	if (streq(name, SOCFPGA_NAND_CLK) ||
 48	    streq(name, SOCFPGA_NAND_X_CLK))
 49		return (perpll_src >> 2) & 3;
 50
 51	/* QSPI clock */
 52	return (perpll_src >> 4) & 3;
 53
 54}
 55
 56static int socfpga_clk_set_parent(struct clk_hw *hwclk, u8 parent)
 57{
 58	u32 src_reg;
 59	const char *name = clk_hw_get_name(hwclk);
 60
 61	if (streq(name, SOCFPGA_L4_MP_CLK)) {
 62		src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
 63		src_reg &= ~0x1;
 64		src_reg |= parent;
 65		writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
 66	} else if (streq(name, SOCFPGA_L4_SP_CLK)) {
 67		src_reg = readl(clk_mgr_base_addr + CLKMGR_L4SRC);
 68		src_reg &= ~0x2;
 69		src_reg |= (parent << 1);
 70		writel(src_reg, clk_mgr_base_addr + CLKMGR_L4SRC);
 71	} else {
 72		src_reg = readl(clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
 73		if (streq(name, SOCFPGA_MMC_CLK)) {
 74			src_reg &= ~0x3;
 75			src_reg |= parent;
 76		} else if (streq(name, SOCFPGA_NAND_CLK) ||
 77			streq(name, SOCFPGA_NAND_X_CLK)) {
 78			src_reg &= ~0xC;
 79			src_reg |= (parent << 2);
 80		} else {/* QSPI clock */
 81			src_reg &= ~0x30;
 82			src_reg |= (parent << 4);
 83		}
 84		writel(src_reg, clk_mgr_base_addr + CLKMGR_PERPLL_SRC);
 85	}
 86
 87	return 0;
 88}
 89
 90static u32 socfpga_clk_get_div(struct socfpga_gate_clk *socfpgaclk)
 91{
 92	u32 div = 1, val;
 93
 94	if (socfpgaclk->fixed_div)
 95		div = socfpgaclk->fixed_div;
 96	else if (socfpgaclk->div_reg) {
 97		val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
 98		val &= GENMASK(socfpgaclk->width - 1, 0);
 99		/* Check for GPIO_DB_CLK by its offset */
100		if ((uintptr_t) socfpgaclk->div_reg & SOCFPGA_GPIO_DB_CLK_OFFSET)
101			div = val + 1;
102		else
103			div = (1 << val);
104	}
105
106	return div;
107}
108
109static unsigned long socfpga_clk_recalc_rate(struct clk_hw *hwclk,
110					     unsigned long parent_rate)
111{
112	struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
113	u32 div = socfpga_clk_get_div(socfpgaclk);
114
115	return parent_rate / div;
116}
117
118
119static int socfpga_clk_determine_rate(struct clk_hw *hwclk,
120				      struct clk_rate_request *req)
121{
122	struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
123	u32 div = socfpga_clk_get_div(socfpgaclk);
124
125	req->rate = req->best_parent_rate / div;
126
127	return 0;
128}
129
130static struct clk_ops gateclk_ops = {
131	.recalc_rate = socfpga_clk_recalc_rate,
132	.determine_rate = socfpga_clk_determine_rate,
133	.get_parent = socfpga_clk_get_parent,
134	.set_parent = socfpga_clk_set_parent,
135};
136
137void __init socfpga_gate_init(struct device_node *node)
138{
139	u32 clk_gate[2];
140	u32 div_reg[3];
141	u32 fixed_div;
142	struct clk_hw *hw_clk;
143	struct socfpga_gate_clk *socfpga_clk;
144	const char *clk_name = node->name;
145	const char *parent_name[SOCFPGA_MAX_PARENTS];
146	struct clk_init_data init;
147	struct clk_ops *ops;
148	int rc;
149
150	socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
151	if (WARN_ON(!socfpga_clk))
152		return;
153
154	ops = kmemdup(&gateclk_ops, sizeof(gateclk_ops), GFP_KERNEL);
155	if (WARN_ON(!ops))
156		goto err_kmemdup;
157
158	rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
159	if (rc)
160		clk_gate[0] = 0;
161
162	if (clk_gate[0]) {
163		socfpga_clk->hw.reg = clk_mgr_base_addr + clk_gate[0];
164		socfpga_clk->hw.bit_idx = clk_gate[1];
165
166		ops->enable = clk_gate_ops.enable;
167		ops->disable = clk_gate_ops.disable;
168	}
169
170	rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
171	if (rc)
172		socfpga_clk->fixed_div = 0;
173	else
174		socfpga_clk->fixed_div = fixed_div;
175
176	rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
177	if (!rc) {
178		socfpga_clk->div_reg = clk_mgr_base_addr + div_reg[0];
179		socfpga_clk->shift = div_reg[1];
180		socfpga_clk->width = div_reg[2];
181	} else {
182		socfpga_clk->div_reg = NULL;
183	}
184
185	of_property_read_string(node, "clock-output-names", &clk_name);
186
187	init.name = clk_name;
188	init.ops = ops;
189	init.flags = 0;
190
191	init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
192	if (init.num_parents < 2) {
193		ops->get_parent = NULL;
194		ops->set_parent = NULL;
195	}
196
197	init.parent_names = parent_name;
198	socfpga_clk->hw.hw.init = &init;
199
200	hw_clk = &socfpga_clk->hw.hw;
201
202	rc = clk_hw_register(NULL, hw_clk);
203	if (rc) {
204		pr_err("Could not register clock:%s\n", clk_name);
205		goto err_clk_hw_register;
206	}
207
208	rc = of_clk_add_hw_provider(node, of_clk_hw_simple_get, hw_clk);
209	if (rc) {
210		pr_err("Could not register clock provider for node:%s\n",
211		       clk_name);
212		goto err_of_clk_add_hw_provider;
213	}
214
215	return;
216
217err_of_clk_add_hw_provider:
218	clk_hw_unregister(hw_clk);
219err_clk_hw_register:
220	kfree(ops);
221err_kmemdup:
222	kfree(socfpga_clk);
223}