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 = {
  60         .vid_in_width = 0x2,
  61         .phyts_width = 0x2,
  62         .phyts_per_pixel = VTAC_5_PPP,
  63 };
  64 static const struct sti_vtac_mode vtac_mode_aux = {
  65         .vid_in_width = 0x1,
  66         .phyts_width = 0x0,
  67         .phyts_per_pixel = VTAC_17_PPP,
  68 };
  69
  70 /**
  71  * VTAC structure
  72  *
  73  * @dev: pointer to device structure
  74  * @regs: ioremapped registers for RX and TX devices
  75  * @phy_regs: phy registers for TX device
  76  * @clk: clock
  77  * @mode: main or auxillary configuration mode
  78  */
  79 struct sti_vtac {
  80         struct device *dev;
  81         void __iomem *regs;
  82         void __iomem *phy_regs;
  83         struct clk *clk;
  84         const struct sti_vtac_mode *mode;
  85 };
  86
  87 static void sti_vtac_rx_set_config(struct sti_vtac *vtac)
  88 {
  89         u32 config;
  90
  91         /* Enable VTAC clock */
  92         if (clk_prepare_enable(vtac->clk))
  93                 DRM_ERROR("Failed to prepare/enable vtac_rx clock.\n");
  94
  95         writel(VTAC_FIFO_CONFIG_VAL, vtac->regs + VTAC_RX_FIFO_CONFIG);
  96
  97         config = VTAC_ENABLE;
  98         config |= vtac->mode->vid_in_width << 4;
  99         config |= vtac->mode->phyts_width << 16;
 100         config |= vtac->mode->phyts_per_pixel << 23;
 101         writel(config, vtac->regs + VTAC_CONFIG);
 102 }
 103
 104 static void sti_vtac_tx_set_config(struct sti_vtac *vtac)
 105 {
 106         u32 phy_config;
 107         u32 config;
 108
 109         /* Enable VTAC clock */
 110         if (clk_prepare_enable(vtac->clk))
 111                 DRM_ERROR("Failed to prepare/enable vtac_tx clock.\n");
 112
 113         /* Configure vtac phy */
 114         phy_config = 0x00000000;
 115         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8522);
 116         phy_config = VTAC_TX_PHY_ENABLE_CLK_PHY;
 117         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 118         phy_config = readl(vtac->phy_regs + VTAC_SYS_CFG8521);
 119         phy_config |= VTAC_TX_PHY_PROG_N3;
 120         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 121         phy_config = readl(vtac->phy_regs + VTAC_SYS_CFG8521);
 122         phy_config |= VTAC_TX_PHY_ENABLE_CLK_DLL;
 123         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 124         phy_config = readl(vtac->phy_regs + VTAC_SYS_CFG8521);
 125         phy_config |= VTAC_TX_PHY_RST_N_DLL_SWITCH;
 126         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 127         phy_config = readl(vtac->phy_regs + VTAC_SYS_CFG8521);
 128         phy_config |= VTAC_TX_PHY_PLL_NOT_OSC_MODE;
 129         writel(phy_config, vtac->phy_regs + VTAC_SYS_CFG8521);
 130
 131         /* Configure vtac tx */
 132         config = VTAC_ENABLE;
 133         config |= vtac->mode->vid_in_width << 4;
 134         config |= vtac->mode->phyts_width << 16;
 135         config |= vtac->mode->phyts_per_pixel << 23;
 136         writel(config, vtac->regs + VTAC_CONFIG);
 137 }
 138
 139 static const struct of_device_id vtac_of_match[] = {
 140         {
 141                 .compatible = "st,vtac-main",
 142                 .data = &vtac_mode_main,
 143         }, {
 144                 .compatible = "st,vtac-aux",
 145                 .data = &vtac_mode_aux,
 146         }, {
 147                 /* end node */
 148         }
 149 };
 150 MODULE_DEVICE_TABLE(of, vtac_of_match);
 151
 152 static int sti_vtac_probe(struct platform_device *pdev)
 153 {
 154         struct device *dev = &pdev->dev;
 155         struct device_node *np = dev->of_node;
 156         const struct of_device_id *id;
 157         struct sti_vtac *vtac;
 158         struct resource *res;
 159
 160         vtac = devm_kzalloc(dev, sizeof(*vtac), GFP_KERNEL);
 161         if (!vtac)
 162                 return -ENOMEM;
 163
 164         vtac->dev = dev;
 165
 166         id = of_match_node(vtac_of_match, np);
 167         if (!id)
 168                 return -ENOMEM;
 169
 170         vtac->mode = id->data;
 171
 172         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 173         if (!res) {
 174                 DRM_ERROR("Invalid resource\n");
 175                 return -ENOMEM;
 176         }
 177         vtac->regs = devm_ioremap_resource(dev, res);
 178         if (IS_ERR(vtac->regs))
 179                 return PTR_ERR(vtac->regs);
 180
 181
 182         vtac->clk = devm_clk_get(dev, "vtac");
 183         if (IS_ERR(vtac->clk)) {
 184                 DRM_ERROR("Cannot get vtac clock\n");
 185                 return PTR_ERR(vtac->clk);
 186         }
 187
 188         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 189         if (res) {
 190                 vtac->phy_regs = devm_ioremap_nocache(dev, res->start,
 191                                                  resource_size(res));
 192                 sti_vtac_tx_set_config(vtac);
 193         } else {
 194
 195                 sti_vtac_rx_set_config(vtac);
 196         }
 197
 198         platform_set_drvdata(pdev, vtac);
 199         DRM_INFO("%s %s\n", __func__, dev_name(vtac->dev));
 200
 201         return 0;
 202 }
 203
 204 static int sti_vtac_remove(struct platform_device *pdev)
 205 {
 206         return 0;
 207 }
 208
 209 struct platform_driver sti_vtac_driver = {
 210         .driver = {
 211                 .name = "sti-vtac",
 212                 .owner = THIS_MODULE,
 213                 .of_match_table = vtac_of_match,
 214         },
 215         .probe = sti_vtac_probe,
 216         .remove = sti_vtac_remove,
 217 };
 218
 219 MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
 220 MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
 221 MODULE_LICENSE("GPL");