kernel/drivers/gpu/drm/rcar-du/rcar_du_lvdsenc.c

   1 /*
   2  * rcar_du_lvdsenc.c  --  R-Car Display Unit LVDS Encoder
   3  *
   4  * Copyright (C) 2013-2014 Renesas Electronics Corporation
   5  *
   6  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  */
  13
  14 #include <linux/clk.h>
  15 #include <linux/delay.h>
  16 #include <linux/io.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/slab.h>
  19
  20 #include "rcar_du_drv.h"
  21 #include "rcar_du_encoder.h"
  22 #include "rcar_du_lvdsenc.h"
  23 #include "rcar_lvds_regs.h"
  24
  25 struct rcar_du_lvdsenc {
  26         struct rcar_du_device *dev;
  27
  28         unsigned int index;
  29         void __iomem *mmio;
  30         struct clk *clock;
  31         bool enabled;
  32
  33         enum rcar_lvds_input input;
  34 };
  35
  36 static void rcar_lvds_write(struct rcar_du_lvdsenc *lvds, u32 reg, u32 data)
  37 {
  38         iowrite32(data, lvds->mmio + reg);
  39 }
  40
  41 static int rcar_du_lvdsenc_start(struct rcar_du_lvdsenc *lvds,
  42                                  struct rcar_du_crtc *rcrtc)
  43 {
  44         const struct drm_display_mode *mode = &rcrtc->crtc.mode;
  45         unsigned int freq = mode->clock;
  46         u32 lvdcr0;
  47         u32 lvdhcr;
  48         u32 pllcr;
  49         int ret;
  50
  51         if (lvds->enabled)
  52                 return 0;
  53
  54         ret = clk_prepare_enable(lvds->clock);
  55         if (ret < 0)
  56                 return ret;
  57
  58         /* PLL clock configuration */
  59         if (freq <= 38000)
  60                 pllcr = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_38M;
  61         else if (freq <= 60000)
  62                 pllcr = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_60M;
  63         else if (freq <= 121000)
  64                 pllcr = LVDPLLCR_CEEN | LVDPLLCR_COSEL | LVDPLLCR_PLLDLYCNT_121M;
  65         else
  66                 pllcr = LVDPLLCR_PLLDLYCNT_150M;
  67
  68         rcar_lvds_write(lvds, LVDPLLCR, pllcr);
  69
  70         /* Hardcode the channels and control signals routing for now.
  71          *
  72          * HSYNC -> CTRL0
  73          * VSYNC -> CTRL1
  74          * DISP  -> CTRL2
  75          * 0     -> CTRL3
  76          */
  77         rcar_lvds_write(lvds, LVDCTRCR, LVDCTRCR_CTR3SEL_ZERO |
  78                         LVDCTRCR_CTR2SEL_DISP | LVDCTRCR_CTR1SEL_VSYNC |
  79                         LVDCTRCR_CTR0SEL_HSYNC);
  80
  81         if (rcar_du_needs(lvds->dev, RCAR_DU_QUIRK_LVDS_LANES))
  82                 lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 3)
  83                        | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 1);
  84         else
  85                 lvdhcr = LVDCHCR_CHSEL_CH(0, 0) | LVDCHCR_CHSEL_CH(1, 1)
  86                        | LVDCHCR_CHSEL_CH(2, 2) | LVDCHCR_CHSEL_CH(3, 3);
  87
  88         rcar_lvds_write(lvds, LVDCHCR, lvdhcr);
  89
  90         /* Select the input, hardcode mode 0, enable LVDS operation and turn
  91          * bias circuitry on.
  92          */
  93         lvdcr0 = LVDCR0_BEN | LVDCR0_LVEN;
  94         if (rcrtc->index == 2)
  95                 lvdcr0 |= LVDCR0_DUSEL;
  96         rcar_lvds_write(lvds, LVDCR0, lvdcr0);
  97
  98         /* Turn all the channels on. */
  99         rcar_lvds_write(lvds, LVDCR1, LVDCR1_CHSTBY(3) | LVDCR1_CHSTBY(2) |
 100                         LVDCR1_CHSTBY(1) | LVDCR1_CHSTBY(0) | LVDCR1_CLKSTBY);
 101
 102         /* Turn the PLL on, wait for the startup delay, and turn the output
 103          * on.
 104          */
 105         lvdcr0 |= LVDCR0_PLLEN;
 106         rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 107
 108         usleep_range(100, 150);
 109
 110         lvdcr0 |= LVDCR0_LVRES;
 111         rcar_lvds_write(lvds, LVDCR0, lvdcr0);
 112
 113         lvds->enabled = true;
 114         return 0;
 115 }
 116
 117 static void rcar_du_lvdsenc_stop(struct rcar_du_lvdsenc *lvds)
 118 {
 119         if (!lvds->enabled)
 120                 return;
 121
 122         rcar_lvds_write(lvds, LVDCR0, 0);
 123         rcar_lvds_write(lvds, LVDCR1, 0);
 124
 125         clk_disable_unprepare(lvds->clock);
 126
 127         lvds->enabled = false;
 128 }
 129
 130 int rcar_du_lvdsenc_enable(struct rcar_du_lvdsenc *lvds, struct drm_crtc *crtc,
 131                            bool enable)
 132 {
 133         if (!enable) {
 134                 rcar_du_lvdsenc_stop(lvds);
 135                 return 0;
 136         } else if (crtc) {
 137                 struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
 138                 return rcar_du_lvdsenc_start(lvds, rcrtc);
 139         } else
 140                 return -EINVAL;
 141 }
 142
 143 static int rcar_du_lvdsenc_get_resources(struct rcar_du_lvdsenc *lvds,
 144                                          struct platform_device *pdev)
 145 {
 146         struct resource *mem;
 147         char name[7];
 148
 149         sprintf(name, "lvds.%u", lvds->index);
 150
 151         mem = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
 152         lvds->mmio = devm_ioremap_resource(&pdev->dev, mem);
 153         if (IS_ERR(lvds->mmio))
 154                 return PTR_ERR(lvds->mmio);
 155
 156         lvds->clock = devm_clk_get(&pdev->dev, name);
 157         if (IS_ERR(lvds->clock)) {
 158                 dev_err(&pdev->dev, "failed to get clock for %s\n", name);
 159                 return PTR_ERR(lvds->clock);
 160         }
 161
 162         return 0;
 163 }
 164
 165 int rcar_du_lvdsenc_init(struct rcar_du_device *rcdu)
 166 {
 167         struct platform_device *pdev = to_platform_device(rcdu->dev);
 168         struct rcar_du_lvdsenc *lvds;
 169         unsigned int i;
 170         int ret;
 171
 172         for (i = 0; i < rcdu->info->num_lvds; ++i) {
 173                 lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
 174                 if (lvds == NULL) {
 175                         dev_err(&pdev->dev, "failed to allocate private data\n");
 176                         return -ENOMEM;
 177                 }
 178
 179                 lvds->dev = rcdu;
 180                 lvds->index = i;
 181                 lvds->input = i ? RCAR_LVDS_INPUT_DU1 : RCAR_LVDS_INPUT_DU0;
 182                 lvds->enabled = false;
 183
 184                 ret = rcar_du_lvdsenc_get_resources(lvds, pdev);
 185                 if (ret < 0)
 186                         return ret;
 187
 188                 rcdu->lvds[i] = lvds;
 189         }
 190
 191         return 0;
 192 }