linux/drivers/clk/socfpga/clk-pll.c

133 lines
3.6 KiB
C

/*
* Copyright 2011-2012 Calxeda, Inc.
* Copyright (C) 2012-2013 Altera Corporation <www.altera.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that 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.
*
* Based from clk-highbank.c
*
*/
#include <linux/slab.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include "clk.h"
/* Clock bypass bits */
#define MAINPLL_BYPASS (1<<0)
#define SDRAMPLL_BYPASS (1<<1)
#define SDRAMPLL_SRC_BYPASS (1<<2)
#define PERPLL_BYPASS (1<<3)
#define PERPLL_SRC_BYPASS (1<<4)
#define SOCFPGA_PLL_BG_PWRDWN 0
#define SOCFPGA_PLL_EXT_ENA 1
#define SOCFPGA_PLL_PWR_DOWN 2
#define SOCFPGA_PLL_DIVF_MASK 0x0000FFF8
#define SOCFPGA_PLL_DIVF_SHIFT 3
#define SOCFPGA_PLL_DIVQ_MASK 0x003F0000
#define SOCFPGA_PLL_DIVQ_SHIFT 16
#define CLK_MGR_PLL_CLK_SRC_SHIFT 22
#define CLK_MGR_PLL_CLK_SRC_MASK 0x3
#define to_socfpga_clk(p) container_of(p, struct socfpga_pll, hw.hw)
void __iomem *clk_mgr_base_addr;
static unsigned long clk_pll_recalc_rate(struct clk_hw *hwclk,
unsigned long parent_rate)
{
struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
unsigned long divf, divq, reg;
unsigned long long vco_freq;
unsigned long bypass;
reg = readl(socfpgaclk->hw.reg);
bypass = readl(clk_mgr_base_addr + CLKMGR_BYPASS);
if (bypass & MAINPLL_BYPASS)
return parent_rate;
divf = (reg & SOCFPGA_PLL_DIVF_MASK) >> SOCFPGA_PLL_DIVF_SHIFT;
divq = (reg & SOCFPGA_PLL_DIVQ_MASK) >> SOCFPGA_PLL_DIVQ_SHIFT;
vco_freq = (unsigned long long)parent_rate * (divf + 1);
do_div(vco_freq, (1 + divq));
return (unsigned long)vco_freq;
}
static u8 clk_pll_get_parent(struct clk_hw *hwclk)
{
u32 pll_src;
struct socfpga_pll *socfpgaclk = to_socfpga_clk(hwclk);
pll_src = readl(socfpgaclk->hw.reg);
return (pll_src >> CLK_MGR_PLL_CLK_SRC_SHIFT) &
CLK_MGR_PLL_CLK_SRC_MASK;
}
static struct clk_ops clk_pll_ops = {
.recalc_rate = clk_pll_recalc_rate,
.get_parent = clk_pll_get_parent,
};
static __init struct clk *__socfpga_pll_init(struct device_node *node,
const struct clk_ops *ops)
{
u32 reg;
struct clk *clk;
struct socfpga_pll *pll_clk;
const char *clk_name = node->name;
const char *parent_name[SOCFPGA_MAX_PARENTS];
struct clk_init_data init;
struct device_node *clkmgr_np;
int rc;
of_property_read_u32(node, "reg", &reg);
pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
if (WARN_ON(!pll_clk))
return NULL;
clkmgr_np = of_find_compatible_node(NULL, NULL, "altr,clk-mgr");
clk_mgr_base_addr = of_iomap(clkmgr_np, 0);
BUG_ON(!clk_mgr_base_addr);
pll_clk->hw.reg = clk_mgr_base_addr + reg;
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;
pll_clk->hw.hw.init = &init;
pll_clk->hw.bit_idx = SOCFPGA_PLL_EXT_ENA;
clk_pll_ops.enable = clk_gate_ops.enable;
clk_pll_ops.disable = clk_gate_ops.disable;
clk = clk_register(NULL, &pll_clk->hw.hw);
if (WARN_ON(IS_ERR(clk))) {
kfree(pll_clk);
return NULL;
}
rc = of_clk_add_provider(node, of_clk_src_simple_get, clk);
return clk;
}
void __init socfpga_pll_init(struct device_node *node)
{
__socfpga_pll_init(node, &clk_pll_ops);
}