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linux-next/drivers/clk/socfpga/clk-gate-s10.c
Dinh Nguyen 07afb8db73 clk: socfpga: stratix10: add clock driver for Stratix10 platform
Add a clock driver for the Stratix10 SoC. The driver is similar to the
Cyclone5/Arria10 platforms, with the exception that this driver only uses
one single clock binding.

Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2018-04-06 10:12:35 -07:00

126 lines
3.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2017, Intel Corporation
*/
#include <linux/clk-provider.h>
#include <linux/slab.h>
#include "stratix10-clk.h"
#include "clk.h"
#define SOCFPGA_CS_PDBG_CLK "cs_pdbg_clk"
#define to_socfpga_gate_clk(p) container_of(p, struct socfpga_gate_clk, hw.hw)
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 unsigned long socfpga_dbg_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;
val = readl(socfpgaclk->div_reg) >> socfpgaclk->shift;
val &= GENMASK(socfpgaclk->width - 1, 0);
div = (1 << val);
div = div ? 4 : 1;
return parent_rate / div;
}
static u8 socfpga_gate_get_parent(struct clk_hw *hwclk)
{
struct socfpga_gate_clk *socfpgaclk = to_socfpga_gate_clk(hwclk);
u32 mask;
u8 parent = 0;
if (socfpgaclk->bypass_reg) {
mask = (0x1 << socfpgaclk->bypass_shift);
parent = ((readl(socfpgaclk->bypass_reg) & mask) >>
socfpgaclk->bypass_shift);
}
return parent;
}
static struct clk_ops gateclk_ops = {
.recalc_rate = socfpga_gate_clk_recalc_rate,
.get_parent = socfpga_gate_get_parent,
};
static const struct clk_ops dbgclk_ops = {
.recalc_rate = socfpga_dbg_clk_recalc_rate,
.get_parent = socfpga_gate_get_parent,
};
struct clk *s10_register_gate(const char *name, const char *parent_name,
const char * const *parent_names,
u8 num_parents, unsigned long flags,
void __iomem *regbase, unsigned long gate_reg,
unsigned long gate_idx, unsigned long div_reg,
unsigned long div_offset, u8 div_width,
unsigned long bypass_reg, u8 bypass_shift,
u8 fixed_div)
{
struct clk *clk;
struct socfpga_gate_clk *socfpga_clk;
struct clk_init_data init;
socfpga_clk = kzalloc(sizeof(*socfpga_clk), GFP_KERNEL);
if (!socfpga_clk)
return NULL;
socfpga_clk->hw.reg = regbase + gate_reg;
socfpga_clk->hw.bit_idx = gate_idx;
gateclk_ops.enable = clk_gate_ops.enable;
gateclk_ops.disable = clk_gate_ops.disable;
socfpga_clk->fixed_div = fixed_div;
if (div_reg)
socfpga_clk->div_reg = regbase + div_reg;
else
socfpga_clk->div_reg = NULL;
socfpga_clk->width = div_width;
socfpga_clk->shift = div_offset;
if (bypass_reg)
socfpga_clk->bypass_reg = regbase + bypass_reg;
else
socfpga_clk->bypass_reg = NULL;
socfpga_clk->bypass_shift = bypass_shift;
if (streq(name, "cs_pdbg_clk"))
init.ops = &dbgclk_ops;
else
init.ops = &gateclk_ops;
init.name = name;
init.flags = flags;
init.num_parents = num_parents;
init.parent_names = parent_names ? 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 NULL;
}
return clk;
}