u-boot/drivers/clk/imx/clk-gate2.c
Michael Trimarchi d2e82ad9e0 clk: imx: gate2 support shared counter and relative clock functions
Add shared counter in order to avoid to swich off clock that
are already used.

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Reviewed-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
2022-10-09 10:42:26 +02:00

129 lines
2.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 DENX Software Engineering
* Lukasz Majewski, DENX Software Engineering, lukma@denx.de
*
* Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
* Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Gated clock implementation
*
*/
#include <common.h>
#include <asm/io.h>
#include <malloc.h>
#include <clk-uclass.h>
#include <dm/device.h>
#include <dm/devres.h>
#include <linux/bug.h>
#include <linux/clk-provider.h>
#include <clk.h>
#include "clk.h"
#include <linux/err.h>
#define UBOOT_DM_CLK_IMX_GATE2 "imx_clk_gate2"
struct clk_gate2 {
struct clk clk;
void __iomem *reg;
u8 bit_idx;
u8 cgr_val;
u8 flags;
unsigned int *share_count;
};
#define to_clk_gate2(_clk) container_of(_clk, struct clk_gate2, clk)
static int clk_gate2_enable(struct clk *clk)
{
struct clk_gate2 *gate = to_clk_gate2(clk);
u32 reg;
if (gate->share_count && (*gate->share_count)++ > 0)
return 0;
reg = readl(gate->reg);
reg &= ~(3 << gate->bit_idx);
reg |= gate->cgr_val << gate->bit_idx;
writel(reg, gate->reg);
return 0;
}
static int clk_gate2_disable(struct clk *clk)
{
struct clk_gate2 *gate = to_clk_gate2(clk);
u32 reg;
if (gate->share_count) {
if (WARN_ON(*gate->share_count == 0))
return 0;
else if (--(*gate->share_count) > 0)
return 0;
}
reg = readl(gate->reg);
reg &= ~(3 << gate->bit_idx);
writel(reg, gate->reg);
return 0;
}
static ulong clk_gate2_set_rate(struct clk *clk, ulong rate)
{
struct clk *parent = clk_get_parent(clk);
if (parent)
return clk_set_rate(parent, rate);
return -ENODEV;
}
static const struct clk_ops clk_gate2_ops = {
.set_rate = clk_gate2_set_rate,
.enable = clk_gate2_enable,
.disable = clk_gate2_disable,
.get_rate = clk_generic_get_rate,
};
struct clk *clk_register_gate2(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
void __iomem *reg, u8 bit_idx, u8 cgr_val,
u8 clk_gate2_flags, unsigned int *share_count)
{
struct clk_gate2 *gate;
struct clk *clk;
int ret;
gate = kzalloc(sizeof(*gate), GFP_KERNEL);
if (!gate)
return ERR_PTR(-ENOMEM);
gate->reg = reg;
gate->bit_idx = bit_idx;
gate->cgr_val = cgr_val;
gate->flags = clk_gate2_flags;
gate->share_count = share_count;
clk = &gate->clk;
ret = clk_register(clk, UBOOT_DM_CLK_IMX_GATE2, name, parent_name);
if (ret) {
kfree(gate);
return ERR_PTR(ret);
}
return clk;
}
U_BOOT_DRIVER(clk_gate2) = {
.name = UBOOT_DM_CLK_IMX_GATE2,
.id = UCLASS_CLK,
.ops = &clk_gate2_ops,
.flags = DM_FLAG_PRE_RELOC,
};