linux/drivers/gpu/drm/msm/disp/mdp4/mdp4_lvds_pll.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2014 Red Hat
   4 * Author: Rob Clark <robdclark@gmail.com>
   5 */
   6
   7#include <linux/clk.h>
   8#include <linux/clk-provider.h>
   9
  10#include "mdp4_kms.h"
  11
  12struct mdp4_lvds_pll {
  13        struct clk_hw pll_hw;
  14        struct drm_device *dev;
  15        unsigned long pixclk;
  16};
  17#define to_mdp4_lvds_pll(x) container_of(x, struct mdp4_lvds_pll, pll_hw)
  18
  19static struct mdp4_kms *get_kms(struct mdp4_lvds_pll *lvds_pll)
  20{
  21        struct msm_drm_private *priv = lvds_pll->dev->dev_private;
  22        return to_mdp4_kms(to_mdp_kms(priv->kms));
  23}
  24
  25struct pll_rate {
  26        unsigned long rate;
  27        struct {
  28                uint32_t val;
  29                uint32_t reg;
  30        } conf[32];
  31};
  32
  33/* NOTE: keep sorted highest freq to lowest: */
  34static const struct pll_rate freqtbl[] = {
  35        { 72000000, {
  36                { 0x8f, REG_MDP4_LVDS_PHY_PLL_CTRL_1 },
  37                { 0x30, REG_MDP4_LVDS_PHY_PLL_CTRL_2 },
  38                { 0xc6, REG_MDP4_LVDS_PHY_PLL_CTRL_3 },
  39                { 0x10, REG_MDP4_LVDS_PHY_PLL_CTRL_5 },
  40                { 0x07, REG_MDP4_LVDS_PHY_PLL_CTRL_6 },
  41                { 0x62, REG_MDP4_LVDS_PHY_PLL_CTRL_7 },
  42                { 0x41, REG_MDP4_LVDS_PHY_PLL_CTRL_8 },
  43                { 0x0d, REG_MDP4_LVDS_PHY_PLL_CTRL_9 },
  44                { 0, 0 } }
  45        },
  46};
  47
  48static const struct pll_rate *find_rate(unsigned long rate)
  49{
  50        int i;
  51        for (i = 1; i < ARRAY_SIZE(freqtbl); i++)
  52                if (rate > freqtbl[i].rate)
  53                        return &freqtbl[i-1];
  54        return &freqtbl[i-1];
  55}
  56
  57static int mpd4_lvds_pll_enable(struct clk_hw *hw)
  58{
  59        struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
  60        struct mdp4_kms *mdp4_kms = get_kms(lvds_pll);
  61        const struct pll_rate *pll_rate = find_rate(lvds_pll->pixclk);
  62        int i;
  63
  64        DBG("pixclk=%lu (%lu)", lvds_pll->pixclk, pll_rate->rate);
  65
  66        if (WARN_ON(!pll_rate))
  67                return -EINVAL;
  68
  69        mdp4_write(mdp4_kms, REG_MDP4_LCDC_LVDS_PHY_RESET, 0x33);
  70
  71        for (i = 0; pll_rate->conf[i].reg; i++)
  72                mdp4_write(mdp4_kms, pll_rate->conf[i].reg, pll_rate->conf[i].val);
  73
  74        mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_CTRL_0, 0x01);
  75
  76        /* Wait until LVDS PLL is locked and ready */
  77        while (!mdp4_read(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_LOCKED))
  78                cpu_relax();
  79
  80        return 0;
  81}
  82
  83static void mpd4_lvds_pll_disable(struct clk_hw *hw)
  84{
  85        struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
  86        struct mdp4_kms *mdp4_kms = get_kms(lvds_pll);
  87
  88        DBG("");
  89
  90        mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_CFG0, 0x0);
  91        mdp4_write(mdp4_kms, REG_MDP4_LVDS_PHY_PLL_CTRL_0, 0x0);
  92}
  93
  94static unsigned long mpd4_lvds_pll_recalc_rate(struct clk_hw *hw,
  95                                unsigned long parent_rate)
  96{
  97        struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
  98        return lvds_pll->pixclk;
  99}
 100
 101static long mpd4_lvds_pll_round_rate(struct clk_hw *hw, unsigned long rate,
 102                unsigned long *parent_rate)
 103{
 104        const struct pll_rate *pll_rate = find_rate(rate);
 105        return pll_rate->rate;
 106}
 107
 108static int mpd4_lvds_pll_set_rate(struct clk_hw *hw, unsigned long rate,
 109                unsigned long parent_rate)
 110{
 111        struct mdp4_lvds_pll *lvds_pll = to_mdp4_lvds_pll(hw);
 112        lvds_pll->pixclk = rate;
 113        return 0;
 114}
 115
 116
 117static const struct clk_ops mpd4_lvds_pll_ops = {
 118        .enable = mpd4_lvds_pll_enable,
 119        .disable = mpd4_lvds_pll_disable,
 120        .recalc_rate = mpd4_lvds_pll_recalc_rate,
 121        .round_rate = mpd4_lvds_pll_round_rate,
 122        .set_rate = mpd4_lvds_pll_set_rate,
 123};
 124
 125static const char *mpd4_lvds_pll_parents[] = {
 126        "pxo",
 127};
 128
 129static struct clk_init_data pll_init = {
 130        .name = "mpd4_lvds_pll",
 131        .ops = &mpd4_lvds_pll_ops,
 132        .parent_names = mpd4_lvds_pll_parents,
 133        .num_parents = ARRAY_SIZE(mpd4_lvds_pll_parents),
 134};
 135
 136struct clk *mpd4_lvds_pll_init(struct drm_device *dev)
 137{
 138        struct mdp4_lvds_pll *lvds_pll;
 139        struct clk *clk;
 140        int ret;
 141
 142        lvds_pll = devm_kzalloc(dev->dev, sizeof(*lvds_pll), GFP_KERNEL);
 143        if (!lvds_pll) {
 144                ret = -ENOMEM;
 145                goto fail;
 146        }
 147
 148        lvds_pll->dev = dev;
 149
 150        lvds_pll->pll_hw.init = &pll_init;
 151        clk = devm_clk_register(dev->dev, &lvds_pll->pll_hw);
 152        if (IS_ERR(clk)) {
 153                ret = PTR_ERR(clk);
 154                goto fail;
 155        }
 156
 157        return clk;
 158
 159fail:
 160        return ERR_PTR(ret);
 161}
 162