drivers/media/platform/s5p-cec/s5p_cec.c

   1 /* drivers/media/platform/s5p-cec/s5p_cec.c
   2  *
   3  * Samsung S5P CEC driver
   4  *
   5  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This driver is based on the "cec interface driver for exynos soc" by
  13  * SangPil Moon.
  14  */
  15
  16 #include <linux/clk.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/kernel.h>
  19 #include <linux/mfd/syscon.h>
  20 #include <linux/module.h>
  21 #include <linux/of.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/pm_runtime.h>
  25 #include <linux/timer.h>
  26 #include <linux/workqueue.h>
  27 #include <media/cec.h>
  28 #include <media/cec-notifier.h>
  29
  30 #include "exynos_hdmi_cec.h"
  31 #include "regs-cec.h"
  32 #include "s5p_cec.h"
  33
  34 #define CEC_NAME        "s5p-cec"
  35
  36 static int debug;
  37 module_param(debug, int, 0644);
  38 MODULE_PARM_DESC(debug, "debug level (0-2)");
  39
  40 static int s5p_cec_adap_enable(struct cec_adapter *adap, bool enable)
  41 {
  42         struct s5p_cec_dev *cec = cec_get_drvdata(adap);
  43
  44         if (enable) {
  45                 pm_runtime_get_sync(cec->dev);
  46
  47                 s5p_cec_reset(cec);
  48
  49                 s5p_cec_set_divider(cec);
  50                 s5p_cec_threshold(cec);
  51
  52                 s5p_cec_unmask_tx_interrupts(cec);
  53                 s5p_cec_unmask_rx_interrupts(cec);
  54                 s5p_cec_enable_rx(cec);
  55         } else {
  56                 s5p_cec_mask_tx_interrupts(cec);
  57                 s5p_cec_mask_rx_interrupts(cec);
  58                 pm_runtime_put(cec->dev);
  59         }
  60
  61         return 0;
  62 }
  63
  64 static int s5p_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
  65 {
  66         struct s5p_cec_dev *cec = cec_get_drvdata(adap);
  67
  68         s5p_cec_set_addr(cec, addr);
  69         return 0;
  70 }
  71
  72 static int s5p_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
  73                                  u32 signal_free_time, struct cec_msg *msg)
  74 {
  75         struct s5p_cec_dev *cec = cec_get_drvdata(adap);
  76
  77         /*
  78          * Unclear if 0 retries are allowed by the hardware, so have 1 as
  79          * the minimum.
  80          */
  81         s5p_cec_copy_packet(cec, msg->msg, msg->len, max(1, attempts - 1));
  82         return 0;
  83 }
  84
  85 static irqreturn_t s5p_cec_irq_handler(int irq, void *priv)
  86 {
  87         struct s5p_cec_dev *cec = priv;
  88         u32 status = 0;
  89
  90         status = s5p_cec_get_status(cec);
  91
  92         dev_dbg(cec->dev, "irq received\n");
  93
  94         if (status & CEC_STATUS_TX_DONE) {
  95                 if (status & CEC_STATUS_TX_NACK) {
  96                         dev_dbg(cec->dev, "CEC_STATUS_TX_NACK set\n");
  97                         cec->tx = STATE_NACK;
  98                 } else if (status & CEC_STATUS_TX_ERROR) {
  99                         dev_dbg(cec->dev, "CEC_STATUS_TX_ERROR set\n");
 100                         cec->tx = STATE_ERROR;
 101                 } else {
 102                         dev_dbg(cec->dev, "CEC_STATUS_TX_DONE\n");
 103                         cec->tx = STATE_DONE;
 104                 }
 105                 s5p_clr_pending_tx(cec);
 106         }
 107
 108         if (status & CEC_STATUS_RX_DONE) {
 109                 if (status & CEC_STATUS_RX_ERROR) {
 110                         dev_dbg(cec->dev, "CEC_STATUS_RX_ERROR set\n");
 111                         s5p_cec_rx_reset(cec);
 112                         s5p_cec_enable_rx(cec);
 113                 } else {
 114                         dev_dbg(cec->dev, "CEC_STATUS_RX_DONE set\n");
 115                         if (cec->rx != STATE_IDLE)
 116                                 dev_dbg(cec->dev, "Buffer overrun (worker did not process previous message)\n");
 117                         cec->rx = STATE_BUSY;
 118                         cec->msg.len = status >> 24;
 119                         if (cec->msg.len > CEC_MAX_MSG_SIZE)
 120                                 cec->msg.len = CEC_MAX_MSG_SIZE;
 121                         cec->msg.rx_status = CEC_RX_STATUS_OK;
 122                         s5p_cec_get_rx_buf(cec, cec->msg.len,
 123                                         cec->msg.msg);
 124                         cec->rx = STATE_DONE;
 125                         s5p_cec_enable_rx(cec);
 126                 }
 127                 /* Clear interrupt pending bit */
 128                 s5p_clr_pending_rx(cec);
 129         }
 130         return IRQ_WAKE_THREAD;
 131 }
 132
 133 static irqreturn_t s5p_cec_irq_handler_thread(int irq, void *priv)
 134 {
 135         struct s5p_cec_dev *cec = priv;
 136
 137         dev_dbg(cec->dev, "irq processing thread\n");
 138         switch (cec->tx) {
 139         case STATE_DONE:
 140                 cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
 141                 cec->tx = STATE_IDLE;
 142                 break;
 143         case STATE_NACK:
 144                 cec_transmit_done(cec->adap,
 145                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_NACK,
 146                         0, 1, 0, 0);
 147                 cec->tx = STATE_IDLE;
 148                 break;
 149         case STATE_ERROR:
 150                 cec_transmit_done(cec->adap,
 151                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_ERROR,
 152                         0, 0, 0, 1);
 153                 cec->tx = STATE_IDLE;
 154                 break;
 155         case STATE_BUSY:
 156                 dev_err(cec->dev, "state set to busy, this should not occur here\n");
 157                 break;
 158         default:
 159                 break;
 160         }
 161
 162         switch (cec->rx) {
 163         case STATE_DONE:
 164                 cec_received_msg(cec->adap, &cec->msg);
 165                 cec->rx = STATE_IDLE;
 166                 break;
 167         default:
 168                 break;
 169         }
 170
 171         return IRQ_HANDLED;
 172 }
 173
 174 static const struct cec_adap_ops s5p_cec_adap_ops = {
 175         .adap_enable = s5p_cec_adap_enable,
 176         .adap_log_addr = s5p_cec_adap_log_addr,
 177         .adap_transmit = s5p_cec_adap_transmit,
 178 };
 179
 180 static int s5p_cec_probe(struct platform_device *pdev)
 181 {
 182         struct device *dev = &pdev->dev;
 183         struct device_node *np;
 184         struct platform_device *hdmi_dev;
 185         struct resource *res;
 186         struct s5p_cec_dev *cec;
 187         bool needs_hpd = of_property_read_bool(pdev->dev.of_node, "needs-hpd");
 188         int ret;
 189
 190         np = of_parse_phandle(pdev->dev.of_node, "hdmi-phandle", 0);
 191
 192         if (!np) {
 193                 dev_err(&pdev->dev, "Failed to find hdmi node in device tree\n");
 194                 return -ENODEV;
 195         }
 196         hdmi_dev = of_find_device_by_node(np);
 197         if (hdmi_dev == NULL)
 198                 return -EPROBE_DEFER;
 199
 200         cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
 201         if (!cec)
 202                 return -ENOMEM;
 203
 204         cec->dev = dev;
 205
 206         cec->irq = platform_get_irq(pdev, 0);
 207         if (cec->irq < 0)
 208                 return cec->irq;
 209
 210         ret = devm_request_threaded_irq(dev, cec->irq, s5p_cec_irq_handler,
 211                 s5p_cec_irq_handler_thread, 0, pdev->name, cec);
 212         if (ret)
 213                 return ret;
 214
 215         cec->clk = devm_clk_get(dev, "hdmicec");
 216         if (IS_ERR(cec->clk))
 217                 return PTR_ERR(cec->clk);
 218
 219         cec->pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
 220                                                  "samsung,syscon-phandle");
 221         if (IS_ERR(cec->pmu))
 222                 return -EPROBE_DEFER;
 223
 224         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 225         cec->reg = devm_ioremap_resource(dev, res);
 226         if (IS_ERR(cec->reg))
 227                 return PTR_ERR(cec->reg);
 228
 229         cec->notifier = cec_notifier_get(&hdmi_dev->dev);
 230         if (cec->notifier == NULL)
 231                 return -ENOMEM;
 232
 233         cec->adap = cec_allocate_adapter(&s5p_cec_adap_ops, cec, CEC_NAME,
 234                 CEC_CAP_DEFAULTS | (needs_hpd ? CEC_CAP_NEEDS_HPD : 0), 1);
 235         ret = PTR_ERR_OR_ZERO(cec->adap);
 236         if (ret)
 237                 return ret;
 238
 239         ret = cec_register_adapter(cec->adap, &pdev->dev);
 240         if (ret)
 241                 goto err_delete_adapter;
 242
 243         cec_register_cec_notifier(cec->adap, cec->notifier);
 244
 245         platform_set_drvdata(pdev, cec);
 246         pm_runtime_enable(dev);
 247
 248         dev_dbg(dev, "successfully probed\n");
 249         return 0;
 250
 251 err_delete_adapter:
 252         cec_delete_adapter(cec->adap);
 253         return ret;
 254 }
 255
 256 static int s5p_cec_remove(struct platform_device *pdev)
 257 {
 258         struct s5p_cec_dev *cec = platform_get_drvdata(pdev);
 259
 260         cec_unregister_adapter(cec->adap);
 261         cec_notifier_put(cec->notifier);
 262         pm_runtime_disable(&pdev->dev);
 263         return 0;
 264 }
 265
 266 static int __maybe_unused s5p_cec_runtime_suspend(struct device *dev)
 267 {
 268         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 269
 270         clk_disable_unprepare(cec->clk);
 271         return 0;
 272 }
 273
 274 static int __maybe_unused s5p_cec_runtime_resume(struct device *dev)
 275 {
 276         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 277         int ret;
 278
 279         ret = clk_prepare_enable(cec->clk);
 280         if (ret < 0)
 281                 return ret;
 282         return 0;
 283 }
 284
 285 static const struct dev_pm_ops s5p_cec_pm_ops = {
 286         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 287                                 pm_runtime_force_resume)
 288         SET_RUNTIME_PM_OPS(s5p_cec_runtime_suspend, s5p_cec_runtime_resume,
 289                            NULL)
 290 };
 291
 292 static const struct of_device_id s5p_cec_match[] = {
 293         {
 294                 .compatible     = "samsung,s5p-cec",
 295         },
 296         {},
 297 };
 298 MODULE_DEVICE_TABLE(of, s5p_cec_match);
 299
 300 static struct platform_driver s5p_cec_pdrv = {
 301         .probe  = s5p_cec_probe,
 302         .remove = s5p_cec_remove,
 303         .driver = {
 304                 .name           = CEC_NAME,
 305                 .of_match_table = s5p_cec_match,
 306                 .pm             = &s5p_cec_pm_ops,
 307         },
 308 };
 309
 310 module_platform_driver(s5p_cec_pdrv);
 311
 312 MODULE_AUTHOR("Kamil Debski <kamil@wypas.org>");
 313 MODULE_LICENSE("GPL");
 314 MODULE_DESCRIPTION("Samsung S5P CEC driver");