drivers/staging/media/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/platform_device.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/timer.h>
  25 #include <linux/version.h>
  26 #include <linux/workqueue.h>
  27 #include <media/cec.h>
  28
  29 #include "exynos_hdmi_cec.h"
  30 #include "regs-cec.h"
  31 #include "s5p_cec.h"
  32
  33 #define CEC_NAME        "s5p-cec"
  34
  35 static int debug;
  36 module_param(debug, int, 0644);
  37 MODULE_PARM_DESC(debug, "debug level (0-2)");
  38
  39 static int s5p_cec_adap_enable(struct cec_adapter *adap, bool enable)
  40 {
  41         struct s5p_cec_dev *cec = adap->priv;
  42
  43         if (enable) {
  44                 pm_runtime_get_sync(cec->dev);
  45
  46                 s5p_cec_reset(cec);
  47
  48                 s5p_cec_set_divider(cec);
  49                 s5p_cec_threshold(cec);
  50
  51                 s5p_cec_unmask_tx_interrupts(cec);
  52                 s5p_cec_unmask_rx_interrupts(cec);
  53                 s5p_cec_enable_rx(cec);
  54         } else {
  55                 s5p_cec_mask_tx_interrupts(cec);
  56                 s5p_cec_mask_rx_interrupts(cec);
  57                 pm_runtime_put(cec->dev);
  58         }
  59
  60         return 0;
  61 }
  62
  63 static int s5p_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
  64 {
  65         struct s5p_cec_dev *cec = adap->priv;
  66
  67         s5p_cec_set_addr(cec, addr);
  68         return 0;
  69 }
  70
  71 static int s5p_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
  72                                  u32 signal_free_time, struct cec_msg *msg)
  73 {
  74         struct s5p_cec_dev *cec = adap->priv;
  75
  76         /*
  77          * Unclear if 0 retries are allowed by the hardware, so have 1 as
  78          * the minimum.
  79          */
  80         s5p_cec_copy_packet(cec, msg->msg, msg->len, max(1, attempts - 1));
  81         return 0;
  82 }
  83
  84 static irqreturn_t s5p_cec_irq_handler(int irq, void *priv)
  85 {
  86         struct s5p_cec_dev *cec = priv;
  87         u32 status = 0;
  88
  89         status = s5p_cec_get_status(cec);
  90
  91         dev_dbg(cec->dev, "irq received\n");
  92
  93         if (status & CEC_STATUS_TX_DONE) {
  94                 if (status & CEC_STATUS_TX_ERROR) {
  95                         dev_dbg(cec->dev, "CEC_STATUS_TX_ERROR set\n");
  96                         cec->tx = STATE_ERROR;
  97                 } else {
  98                         dev_dbg(cec->dev, "CEC_STATUS_TX_DONE\n");
  99                         cec->tx = STATE_DONE;
 100                 }
 101                 s5p_clr_pending_tx(cec);
 102         }
 103
 104         if (status & CEC_STATUS_RX_DONE) {
 105                 if (status & CEC_STATUS_RX_ERROR) {
 106                         dev_dbg(cec->dev, "CEC_STATUS_RX_ERROR set\n");
 107                         s5p_cec_rx_reset(cec);
 108                         s5p_cec_enable_rx(cec);
 109                 } else {
 110                         dev_dbg(cec->dev, "CEC_STATUS_RX_DONE set\n");
 111                         if (cec->rx != STATE_IDLE)
 112                                 dev_dbg(cec->dev, "Buffer overrun (worker did not process previous message)\n");
 113                         cec->rx = STATE_BUSY;
 114                         cec->msg.len = status >> 24;
 115                         if (cec->msg.len > CEC_MAX_MSG_SIZE)
 116                                 cec->msg.len = CEC_MAX_MSG_SIZE;
 117                         cec->msg.rx_status = CEC_RX_STATUS_OK;
 118                         s5p_cec_get_rx_buf(cec, cec->msg.len,
 119                                         cec->msg.msg);
 120                         cec->rx = STATE_DONE;
 121                         s5p_cec_enable_rx(cec);
 122                 }
 123                 /* Clear interrupt pending bit */
 124                 s5p_clr_pending_rx(cec);
 125         }
 126         return IRQ_WAKE_THREAD;
 127 }
 128
 129 static irqreturn_t s5p_cec_irq_handler_thread(int irq, void *priv)
 130 {
 131         struct s5p_cec_dev *cec = priv;
 132
 133         dev_dbg(cec->dev, "irq processing thread\n");
 134         switch (cec->tx) {
 135         case STATE_DONE:
 136                 cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
 137                 cec->tx = STATE_IDLE;
 138                 break;
 139         case STATE_ERROR:
 140                 cec_transmit_done(cec->adap,
 141                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_ERROR,
 142                         0, 0, 0, 1);
 143                 cec->tx = STATE_IDLE;
 144                 break;
 145         case STATE_BUSY:
 146                 dev_err(cec->dev, "state set to busy, this should not occur here\n");
 147                 break;
 148         default:
 149                 break;
 150         }
 151
 152         switch (cec->rx) {
 153         case STATE_DONE:
 154                 cec_received_msg(cec->adap, &cec->msg);
 155                 cec->rx = STATE_IDLE;
 156                 break;
 157         default:
 158                 break;
 159         }
 160
 161         return IRQ_HANDLED;
 162 }
 163
 164 static const struct cec_adap_ops s5p_cec_adap_ops = {
 165         .adap_enable = s5p_cec_adap_enable,
 166         .adap_log_addr = s5p_cec_adap_log_addr,
 167         .adap_transmit = s5p_cec_adap_transmit,
 168 };
 169
 170 static int s5p_cec_probe(struct platform_device *pdev)
 171 {
 172         struct device *dev = &pdev->dev;
 173         struct resource *res;
 174         struct s5p_cec_dev *cec;
 175         int ret;
 176
 177         cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
 178         if (!cec)
 179                 return -ENOMEM;
 180
 181         cec->dev = dev;
 182
 183         cec->irq = platform_get_irq(pdev, 0);
 184         if (cec->irq < 0)
 185                 return cec->irq;
 186
 187         ret = devm_request_threaded_irq(dev, cec->irq, s5p_cec_irq_handler,
 188                 s5p_cec_irq_handler_thread, 0, pdev->name, cec);
 189         if (ret)
 190                 return ret;
 191
 192         cec->clk = devm_clk_get(dev, "hdmicec");
 193         if (IS_ERR(cec->clk))
 194                 return PTR_ERR(cec->clk);
 195
 196         cec->pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
 197                                                  "samsung,syscon-phandle");
 198         if (IS_ERR(cec->pmu))
 199                 return -EPROBE_DEFER;
 200
 201         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 202         cec->reg = devm_ioremap_resource(dev, res);
 203         if (IS_ERR(cec->reg))
 204                 return PTR_ERR(cec->reg);
 205
 206         cec->adap = cec_allocate_adapter(&s5p_cec_adap_ops, cec,
 207                 CEC_NAME,
 208                 CEC_CAP_PHYS_ADDR | CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
 209                 CEC_CAP_PASSTHROUGH | CEC_CAP_RC,
 210                 1, &pdev->dev);
 211         ret = PTR_ERR_OR_ZERO(cec->adap);
 212         if (ret)
 213                 return ret;
 214         ret = cec_register_adapter(cec->adap);
 215         if (ret) {
 216                 cec_delete_adapter(cec->adap);
 217                 return ret;
 218         }
 219
 220         platform_set_drvdata(pdev, cec);
 221         pm_runtime_enable(dev);
 222
 223         dev_dbg(dev, "successfuly probed\n");
 224         return 0;
 225 }
 226
 227 static int s5p_cec_remove(struct platform_device *pdev)
 228 {
 229         struct s5p_cec_dev *cec = platform_get_drvdata(pdev);
 230
 231         cec_unregister_adapter(cec->adap);
 232         pm_runtime_disable(&pdev->dev);
 233         return 0;
 234 }
 235
 236 static int __maybe_unused s5p_cec_runtime_suspend(struct device *dev)
 237 {
 238         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 239
 240         clk_disable_unprepare(cec->clk);
 241         return 0;
 242 }
 243
 244 static int __maybe_unused s5p_cec_runtime_resume(struct device *dev)
 245 {
 246         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 247         int ret;
 248
 249         ret = clk_prepare_enable(cec->clk);
 250         if (ret < 0)
 251                 return ret;
 252         return 0;
 253 }
 254
 255 static const struct dev_pm_ops s5p_cec_pm_ops = {
 256         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 257                                 pm_runtime_force_resume)
 258         SET_RUNTIME_PM_OPS(s5p_cec_runtime_suspend, s5p_cec_runtime_resume,
 259                            NULL)
 260 };
 261
 262 static const struct of_device_id s5p_cec_match[] = {
 263         {
 264                 .compatible     = "samsung,s5p-cec",
 265         },
 266         {},
 267 };
 268
 269 static struct platform_driver s5p_cec_pdrv = {
 270         .probe  = s5p_cec_probe,
 271         .remove = s5p_cec_remove,
 272         .driver = {
 273                 .name           = CEC_NAME,
 274                 .of_match_table = s5p_cec_match,
 275                 .pm             = &s5p_cec_pm_ops,
 276         },
 277 };
 278
 279 module_platform_driver(s5p_cec_pdrv);
 280
 281 MODULE_AUTHOR("Kamil Debski <kamil@wypas.org>");
 282 MODULE_LICENSE("GPL");
 283 MODULE_DESCRIPTION("Samsung S5P CEC driver");