drivers/clk/sunxi-ng/ccu_mmc_timing.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2017 Chen-Yu Tsai. All rights reserved.
   4  */
   5
   6 #include <linux/clk-provider.h>
   7 #include <linux/clk/sunxi-ng.h>
   8 #include <linux/io.h>
   9
  10 #include "ccu_common.h"
  11
  12 /**
  13  * sunxi_ccu_set_mmc_timing_mode: Configure the MMC clock timing mode
  14  * @clk: clock to be configured
  15  * @new_mode: true for new timing mode introduced in A83T and later
  16  *
  17  * Returns 0 on success, -ENOTSUPP if the clock does not support
  18  * switching modes.
  19  */
  20 int sunxi_ccu_set_mmc_timing_mode(struct clk *clk, bool new_mode)
  21 {
  22         struct clk_hw *hw = __clk_get_hw(clk);
  23         struct ccu_common *cm = hw_to_ccu_common(hw);
  24         unsigned long flags;
  25         u32 val;
  26
  27         if (!(cm->features & CCU_FEATURE_MMC_TIMING_SWITCH))
  28                 return -ENOTSUPP;
  29
  30         spin_lock_irqsave(cm->lock, flags);
  31
  32         val = readl(cm->base + cm->reg);
  33         if (new_mode)
  34                 val |= CCU_MMC_NEW_TIMING_MODE;
  35         else
  36                 val &= ~CCU_MMC_NEW_TIMING_MODE;
  37         writel(val, cm->base + cm->reg);
  38
  39         spin_unlock_irqrestore(cm->lock, flags);
  40
  41         return 0;
  42 }
  43 EXPORT_SYMBOL_GPL(sunxi_ccu_set_mmc_timing_mode);
  44
  45 /**
  46  * sunxi_ccu_set_mmc_timing_mode: Get the current MMC clock timing mode
  47  * @clk: clock to query
  48  *
  49  * Returns 0 if the clock is in old timing mode, > 0 if it is in
  50  * new timing mode, and -ENOTSUPP if the clock does not support
  51  * this function.
  52  */
  53 int sunxi_ccu_get_mmc_timing_mode(struct clk *clk)
  54 {
  55         struct clk_hw *hw = __clk_get_hw(clk);
  56         struct ccu_common *cm = hw_to_ccu_common(hw);
  57
  58         if (!(cm->features & CCU_FEATURE_MMC_TIMING_SWITCH))
  59                 return -ENOTSUPP;
  60
  61         return !!(readl(cm->base + cm->reg) & CCU_MMC_NEW_TIMING_MODE);
  62 }
  63 EXPORT_SYMBOL_GPL(sunxi_ccu_get_mmc_timing_mode);