drivers/gpu/drm/sti/sti_vtac.c

   1 /*
   2  * Copyright (C) STMicroelectronics SA 2014
   3  * Author: Benjamin Gaignard <benjamin.gaignard@st.com> for STMicroelectronics.
   4  * License terms:  GNU General Public License (GPL), version 2
   5  */
   6
   7 #include <linux/clk.h>
   8 #include <linux/io.h>
   9 #include <linux/module.h>
  10 #include <linux/of.h>
  11 #include <linux/platform_device.h>
  12
  13 #include <drm/drmP.h>
  14
  15 /* registers offset */
  16 #define VTAC_CONFIG                     0x00
  17 #define VTAC_RX_FIFO_CONFIG             0x04
  18 #define VTAC_FIFO_CONFIG_VAL            0x04
  19
  20 #define VTAC_SYS_CFG8521                0x824
  21 #define VTAC_SYS_CFG8522                0x828
  22
  23 /* Number of phyts per pixel */
  24 #define VTAC_2_5_PPP                    0x0005
  25 #define VTAC_3_PPP                      0x0006
  26 #define VTAC_4_PPP                      0x0008
  27 #define VTAC_5_PPP                      0x000A
  28 #define VTAC_6_PPP                      0x000C
  29 #define VTAC_13_PPP                     0x001A
  30 #define VTAC_14_PPP                     0x001C
  31 #define VTAC_15_PPP                     0x001E
  32 #define VTAC_16_PPP                     0x0020
  33 #define VTAC_17_PPP                     0x0022
  34 #define VTAC_18_PPP                     0x0024
  35
  36 /* enable bits */
  37 #define VTAC_ENABLE                     0x3003
  38
  39 #define VTAC_TX_PHY_ENABLE_CLK_PHY      BIT(0)
  40 #define VTAC_TX_PHY_ENABLE_CLK_DLL      BIT(1)
  41 #define VTAC_TX_PHY_PLL_NOT_OSC_MODE    BIT(3)
  42 #define VTAC_TX_PHY_RST_N_DLL_SWITCH    BIT(4)
  43 #define VTAC_TX_PHY_PROG_N3             BIT(9)
  44
  45
  46 /**
  47  * VTAC mode structure
  48  *
  49  * @vid_in_width: Video Data Resolution
  50  * @phyts_width: Width of phyt buses(phyt low and phyt high).
  51  * @phyts_per_pixel: Number of phyts sent per pixel
  52  */
  53 struct sti_vtac_mode {
  54         u32 vid_in_width;
  55         u32 phyts_width;
  56         u32 phyts_per_pixel;
  57 };
  58
  59 static const struct sti_vtac_mode vtac_mode_main = {0x2, 0x2, VTAC_5_PPP};
  60 static const struct sti_vtac_mode vtac_mode_aux = {0x1, 0x0, VTAC_17_PPP};
  61
  62 /**
  63  * VTAC structure
  64  *
  65  * @dev: pointer to device structure
  66  * @regs: ioremapped registers for RX and TX devices
  67  * @phy_regs: phy registers for TX device
  68  * @clk: clock
  69  * @mode: main or auxillary configuration mode
  70  */
  71 struct sti_vtac {
  72         struct device *dev;
  73         void __iomem *regs;
  74         void __iomem *phy_regs;
  75         struct clk *clk;
  76         const struct sti_vtac_mode *mode;
  77 };
  78
  79 static void sti_vtac_rx_set_config(struct sti_vtac *vtac)
  80 {
  81         u32 config;
  82
  83         /* Enable VTAC clock */
  84         if (clk_prepare_enable(vtac->clk))
  85                 DRM_ERROR("Failed to prepare/enable vtac_rx clock.\n");
  86
  87         writel(VTAC_FIFO_CONFIG_VAL, vtac->regs + VTAC_RX_FIFO_CONFIG);
  88
  89         config = VTAC_ENABLE;
  90         config |= vtac->mode->vid_in_width << 4;
  91         config |= vtac->mode->phyts_width << 16;
  92         config |= vtac->mode->phyts_per_pixel << 23;
  93         writel(config, vtac->regs + VTAC_CONFIG);
  94 }
  95
  96 static void sti_vtac_tx_set_config(struct sti_vtac *vtac)
  97 {
  98         u32 phy_config;
  99         u32 config;
 100
 101         /* Enable VTAC clock */
 102         if (clk_prepare_enable(vtac->clk))
 103                 DRM_ERROR("Failed to prepare/enable vtac_tx clock.\n");
 104
 105         /* Configure vtac phy */
 106         phy_config = 0x00000000;
 107         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8522);
 108         phy_config = VTAC_TX_PHY_ENABLE_CLK_PHY;
 109         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 110         phy_config = readl(vtac->phy_regs + VTAC_SYS_CFG8521);
 111         phy_config |= VTAC_TX_PHY_PROG_N3;
 112         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 113         phy_config = readl(vtac->phy_regs + VTAC_SYS_CFG8521);
 114         phy_config |= VTAC_TX_PHY_ENABLE_CLK_DLL;
 115         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 116         phy_config = readl(vtac->phy_regs + VTAC_SYS_CFG8521);
 117         phy_config |= VTAC_TX_PHY_RST_N_DLL_SWITCH;
 118         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 119         phy_config = readl(vtac->phy_regs + VTAC_SYS_CFG8521);
 120         phy_config |= VTAC_TX_PHY_PLL_NOT_OSC_MODE;
 121         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 122
 123         /* Configure vtac tx */
 124         config = VTAC_ENABLE;
 125         config |= vtac->mode->vid_in_width << 4;
 126         config |= vtac->mode->phyts_width << 16;
 127         config |= vtac->mode->phyts_per_pixel << 23;
 128         writel(config, vtac->regs + VTAC_CONFIG);
 129 }
 130
 131 static const struct of_device_id vtac_of_match[] = {
 132         {
 133                 .compatible = "st,vtac-main",
 134                 .data = &vtac_mode_main,
 135         }, {
 136                 .compatible = "st,vtac-aux",
 137                 .data = &vtac_mode_aux,
 138         }, {
 139                 /* end node */
 140         }
 141 };
 142 MODULE_DEVICE_TABLE(of, vtac_of_match);
 143
 144 static int sti_vtac_probe(struct platform_device *pdev)
 145 {
 146         struct device *dev = &pdev->dev;
 147         struct device_node *np = dev->of_node;
 148         const struct of_device_id *id;
 149         struct sti_vtac *vtac;
 150         struct resource *res;
 151
 152         vtac = devm_kzalloc(dev, sizeof(*vtac), GFP_KERNEL);
 153         if (!vtac)
 154                 return -ENOMEM;
 155
 156         vtac->dev = dev;
 157
 158         id = of_match_node(vtac_of_match, np);
 159         if (!id)
 160                 return -ENOMEM;
 161
 162         vtac->mode = id->data;
 163
 164         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 165         if (!res) {
 166                 DRM_ERROR("Invalid resource\n");
 167                 return -ENOMEM;
 168         }
 169         vtac->regs = devm_ioremap_resource(dev, res);
 170         if (IS_ERR(vtac->regs))
 171                 return PTR_ERR(vtac->regs);
 172
 173
 174         vtac->clk = devm_clk_get(dev, "vtac");
 175         if (IS_ERR(vtac->clk)) {
 176                 DRM_ERROR("Cannot get vtac clock\n");
 177                 return PTR_ERR(vtac->clk);
 178         }
 179
 180         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 181         if (res) {
 182                 vtac->phy_regs = devm_ioremap_nocache(dev, res->start,
 183                                                  resource_size(res));
 184                 sti_vtac_tx_set_config(vtac);
 185         } else {
 186
 187                 sti_vtac_rx_set_config(vtac);
 188         }
 189
 190         platform_set_drvdata(pdev, vtac);
 191         DRM_INFO("%s %s\n", __func__, dev_name(vtac->dev));
 192
 193         return 0;
 194 }
 195
 196 static int sti_vtac_remove(struct platform_device *pdev)
 197 {
 198         return 0;
 199 }
 200
 201 struct platform_driver sti_vtac_driver = {
 202         .driver = {
 203                 .name = "sti-vtac",
 204                 .owner = THIS_MODULE,
 205                 .of_match_table = vtac_of_match,
 206         },
 207         .probe = sti_vtac_probe,
 208         .remove = sti_vtac_remove,
 209 };
 210
 211 module_platform_driver(sti_vtac_driver);
 212
 213 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
 214 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
 215 MODULE_LICENSE("GPL");