linux/drivers/clk/socfpga/clk-gate-a10.c

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/*
* Copyright (C) 2015 Altera Corporation. All rights reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/slab.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/of.h>
#include <linux/regmap.h>
#include "clk.h"
#define streq(a, b) (strcmp((a), (b)) == 0)
#define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
/* SDMMC Group for System Manager defines */
#define SYSMGR_SDMMCGRP_CTRL_OFFSET 0x28
static unsigned long socfpga_gate_clk_recalc_rate(struct clk_hw *hwclk,
unsigned long parent_rate)
{
struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
u32 div = 1, val;
if (socfpgaclk->fixed_div)
div = socfpgaclk->fixed_div;
else if (socfpgaclk->div_reg) {
val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
val &= GENMASK(socfpgaclk->width - 1, 0);
div = (1 << val);
}
return parent_rate / div;
}
static int socfpga_clk_prepare(struct clk_hw *hwclk)
{
struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
int i;
u32 hs_timing;
u32 clk_phase[2];
if (socfpgaclk->clk_phase[0] || socfpgaclk->clk_phase[1]) {
for (i = 0; i < ARRAY_SIZE(clk_phase); i++) {
switch (socfpgaclk->clk_phase[i]) {
case 0:
clk_phase[i] = 0;
break;
case 45:
clk_phase[i] = 1;
break;
case 90:
clk_phase[i] = 2;
break;
case 135:
clk_phase[i] = 3;
break;
case 180:
clk_phase[i] = 4;
break;
case 225:
clk_phase[i] = 5;
break;
case 270:
clk_phase[i] = 6;
break;
case 315:
clk_phase[i] = 7;
break;
default:
clk_phase[i] = 0;
break;
}
}
hs_timing = SYSMGR_SDMMC_CTRL_SET_AS10(clk_phase[0], clk_phase[1]);
if (!IS_ERR(socfpgaclk->sys_mgr_base_addr))
regmap_write(socfpgaclk->sys_mgr_base_addr,
SYSMGR_SDMMCGRP_CTRL_OFFSET, hs_timing);
else
pr_err("%s: cannot set clk_phase because sys_mgr_base_addr is not available!\n",
__func__);
}
return 0;
}
static struct clk_ops gateclk_ops = {
.prepare = socfpga_clk_prepare,
.recalc_rate = socfpga_gate_clk_recalc_rate,
};
static void __init __socfpga_gate_init(struct device_node *node,
const struct clk_ops *ops)
{
u32 clk_gate[2];
u32 div_reg[3];
u32 clk_phase[2];
u32 fixed_div;
struct clk *clk;
struct socfpga_gate_clk *socfpga_clk;
const char *clk_name = node->name;
const char *parent_name[SOCFPGA_MAX_PARENTS];
struct clk_init_data init;
int rc;
socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
if (WARN_ON(!socfpga_clk))
return;
rc = of_property_read_u32_array(node, "clk-gate", clk_gate, 2);
if (rc)
clk_gate[0] = 0;
if (clk_gate[0]) {
socfpga_clk->hw.reg = clk_mgr_a10_base_addr + clk_gate[0];
socfpga_clk->hw.bit_idx = clk_gate[1];
gateclk_ops.enable = clk_gate_ops.enable;
gateclk_ops.disable = clk_gate_ops.disable;
}
rc = of_property_read_u32(node, "fixed-divider", &fixed_div);
if (rc)
socfpga_clk->fixed_div = 0;
else
socfpga_clk->fixed_div = fixed_div;
rc = of_property_read_u32_array(node, "div-reg", div_reg, 3);
if (!rc) {
socfpga_clk->div_reg = clk_mgr_a10_base_addr + div_reg[0];
socfpga_clk->shift = div_reg[1];
socfpga_clk->width = div_reg[2];
} else {
socfpga_clk->div_reg = NULL;
}
rc = of_property_read_u32_array(node, "clk-phase", clk_phase, 2);
if (!rc) {
socfpga_clk->clk_phase[0] = clk_phase[0];
socfpga_clk->clk_phase[1] = clk_phase[1];
socfpga_clk->sys_mgr_base_addr =
syscon_regmap_lookup_by_compatible("altr,sys-mgr");
if (IS_ERR(socfpga_clk->sys_mgr_base_addr)) {
pr_err("%s: failed to find altr,sys-mgr regmap!\n",
__func__);
return;
}
}
of_property_read_string(node, "clock-output-names", &clk_name);
init.name = clk_name;
init.ops = ops;
init.flags = 0;
init.num_parents = of_clk_parent_fill(node, parent_name, SOCFPGA_MAX_PARENTS);
init.parent_names = parent_name;
socfpga_clk->hw.hw.init = &init;
clk = clk_register(NULL, &socfpga_clk->hw.hw);
if (WARN_ON(IS_ERR(clk))) {
kfree(socfpga_clk);
return;
}
rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
if (WARN_ON(rc))
return;
}
void __init socfpga_a10_gate_init(struct device_node *node)
{
__socfpga_gate_init(node, &gateclk_ops);
}