linux-sg2042/drivers/clk/sunxi-ng/ccu_mmc_timing.c

72 lines
2.0 KiB
C

/*
* Copyright (c) 2017 Chen-Yu Tsai. All rights reserved.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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/clk-provider.h>
#include <linux/clk/sunxi-ng.h>
#include <linux/io.h>
#include "ccu_common.h"
/**
* sunxi_ccu_set_mmc_timing_mode: Configure the MMC clock timing mode
* @clk: clock to be configured
* @new_mode: true for new timing mode introduced in A83T and later
*
* Returns 0 on success, -ENOTSUPP if the clock does not support
* switching modes.
*/
int sunxi_ccu_set_mmc_timing_mode(struct clk *clk, bool new_mode)
{
struct clk_hw *hw = __clk_get_hw(clk);
struct ccu_common *cm = hw_to_ccu_common(hw);
unsigned long flags;
u32 val;
if (!(cm->features & CCU_FEATURE_MMC_TIMING_SWITCH))
return -ENOTSUPP;
spin_lock_irqsave(cm->lock, flags);
val = readl(cm->base + cm->reg);
if (new_mode)
val |= CCU_MMC_NEW_TIMING_MODE;
else
val &= ~CCU_MMC_NEW_TIMING_MODE;
writel(val, cm->base + cm->reg);
spin_unlock_irqrestore(cm->lock, flags);
return 0;
}
EXPORT_SYMBOL_GPL(sunxi_ccu_set_mmc_timing_mode);
/**
* sunxi_ccu_set_mmc_timing_mode: Get the current MMC clock timing mode
* @clk: clock to query
*
* Returns 0 if the clock is in old timing mode, > 0 if it is in
* new timing mode, and -ENOTSUPP if the clock does not support
* this function.
*/
int sunxi_ccu_get_mmc_timing_mode(struct clk *clk)
{
struct clk_hw *hw = __clk_get_hw(clk);
struct ccu_common *cm = hw_to_ccu_common(hw);
if (!(cm->features & CCU_FEATURE_MMC_TIMING_SWITCH))
return -ENOTSUPP;
return !!(readl(cm->base + cm->reg) & CCU_MMC_NEW_TIMING_MODE);
}
EXPORT_SYMBOL_GPL(sunxi_ccu_get_mmc_timing_mode);