linux/drivers/clk/mediatek/clk-apmixed.c
James Liao cdb2bab78a clk: mediatek: Add USB clock support in MT8173 APMIXEDSYS
Add REF2USB_TX clock support into MT8173 APMIXEDSYS. This clock
is needed by USB 3.0.

Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Reviewed-by: Daniel Kurtz <djkurtz@chromium.org>
2015-10-01 12:06:00 +08:00

108 lines
2.5 KiB
C

/*
* Copyright (c) 2015 MediaTek Inc.
* Author: James Liao <jamesjj.liao@mediatek.com>
*
* 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.
*
* 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.
*/
#include <linux/delay.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include "clk-mtk.h"
#define REF2USB_TX_EN BIT(0)
#define REF2USB_TX_LPF_EN BIT(1)
#define REF2USB_TX_OUT_EN BIT(2)
#define REF2USB_EN_MASK (REF2USB_TX_EN | REF2USB_TX_LPF_EN | \
REF2USB_TX_OUT_EN)
struct mtk_ref2usb_tx {
struct clk_hw hw;
void __iomem *base_addr;
};
static inline struct mtk_ref2usb_tx *to_mtk_ref2usb_tx(struct clk_hw *hw)
{
return container_of(hw, struct mtk_ref2usb_tx, hw);
}
static int mtk_ref2usb_tx_is_prepared(struct clk_hw *hw)
{
struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
return (readl(tx->base_addr) & REF2USB_EN_MASK) == REF2USB_EN_MASK;
}
static int mtk_ref2usb_tx_prepare(struct clk_hw *hw)
{
struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
u32 val;
val = readl(tx->base_addr);
val |= REF2USB_TX_EN;
writel(val, tx->base_addr);
udelay(100);
val |= REF2USB_TX_LPF_EN;
writel(val, tx->base_addr);
val |= REF2USB_TX_OUT_EN;
writel(val, tx->base_addr);
return 0;
}
static void mtk_ref2usb_tx_unprepare(struct clk_hw *hw)
{
struct mtk_ref2usb_tx *tx = to_mtk_ref2usb_tx(hw);
u32 val;
val = readl(tx->base_addr);
val &= ~REF2USB_EN_MASK;
writel(val, tx->base_addr);
}
static const struct clk_ops mtk_ref2usb_tx_ops = {
.is_prepared = mtk_ref2usb_tx_is_prepared,
.prepare = mtk_ref2usb_tx_prepare,
.unprepare = mtk_ref2usb_tx_unprepare,
};
struct clk * __init mtk_clk_register_ref2usb_tx(const char *name,
const char *parent_name, void __iomem *reg)
{
struct mtk_ref2usb_tx *tx;
struct clk_init_data init = {};
struct clk *clk;
tx = kzalloc(sizeof(*tx), GFP_KERNEL);
if (!tx)
return ERR_PTR(-ENOMEM);
tx->base_addr = reg;
tx->hw.init = &init;
init.name = name;
init.ops = &mtk_ref2usb_tx_ops;
init.parent_names = &parent_name;
init.num_parents = 1;
clk = clk_register(NULL, &tx->hw);
if (IS_ERR(clk)) {
pr_err("Failed to register clk %s: %ld\n", name, PTR_ERR(clk));
kfree(tx);
}
return clk;
}