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

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* drivers/media/platform/s5p-cec/s5p_cec.c
   3  *
   4  * Samsung S5P CEC driver
   5  *
   6  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
   7  *
   8  * This driver is based on the "cec interface driver for exynos soc" by
   9  * SangPil Moon.
  10  */
  11
  12 #include <linux/clk.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/kernel.h>
  15 #include <linux/mfd/syscon.h>
  16 #include <linux/module.h>
  17 #include <linux/of.h>
  18 #include <linux/of_platform.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/timer.h>
  22 #include <linux/workqueue.h>
  23 #include <media/cec.h>
  24 #include <media/cec-notifier.h>
  25
  26 #include "exynos_hdmi_cec.h"
  27 #include "regs-cec.h"
  28 #include "s5p_cec.h"
  29
  30 #define CEC_NAME        "s5p-cec"
  31
  32 static int debug;
  33 module_param(debug, int, 0644);
  34 MODULE_PARM_DESC(debug, "debug level (0-2)");
  35
  36 static int s5p_cec_adap_enable(struct cec_adapter *adap, bool enable)
  37 {
  38         int ret;
  39         struct s5p_cec_dev *cec = cec_get_drvdata(adap);
  40
  41         if (enable) {
  42                 ret = pm_runtime_resume_and_get(cec->dev);
  43                 if (ret < 0)
  44                         return ret;
  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 = cec_get_drvdata(adap);
  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 = cec_get_drvdata(adap);
  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_NACK) {
  95                         dev_dbg(cec->dev, "CEC_STATUS_TX_NACK set\n");
  96                         cec->tx = STATE_NACK;
  97                 } else if (status & CEC_STATUS_TX_ERROR) {
  98                         dev_dbg(cec->dev, "CEC_STATUS_TX_ERROR set\n");
  99                         cec->tx = STATE_ERROR;
 100                 } else {
 101                         dev_dbg(cec->dev, "CEC_STATUS_TX_DONE\n");
 102                         cec->tx = STATE_DONE;
 103                 }
 104                 s5p_clr_pending_tx(cec);
 105         }
 106
 107         if (status & CEC_STATUS_RX_DONE) {
 108                 if (status & CEC_STATUS_RX_ERROR) {
 109                         dev_dbg(cec->dev, "CEC_STATUS_RX_ERROR set\n");
 110                         s5p_cec_rx_reset(cec);
 111                         s5p_cec_enable_rx(cec);
 112                 } else {
 113                         dev_dbg(cec->dev, "CEC_STATUS_RX_DONE set\n");
 114                         if (cec->rx != STATE_IDLE)
 115                                 dev_dbg(cec->dev, "Buffer overrun (worker did not process previous message)\n");
 116                         cec->rx = STATE_BUSY;
 117                         cec->msg.len = status >> 24;
 118                         if (cec->msg.len > CEC_MAX_MSG_SIZE)
 119                                 cec->msg.len = CEC_MAX_MSG_SIZE;
 120                         cec->msg.rx_status = CEC_RX_STATUS_OK;
 121                         s5p_cec_get_rx_buf(cec, cec->msg.len,
 122                                         cec->msg.msg);
 123                         cec->rx = STATE_DONE;
 124                         s5p_cec_enable_rx(cec);
 125                 }
 126                 /* Clear interrupt pending bit */
 127                 s5p_clr_pending_rx(cec);
 128         }
 129         return IRQ_WAKE_THREAD;
 130 }
 131
 132 static irqreturn_t s5p_cec_irq_handler_thread(int irq, void *priv)
 133 {
 134         struct s5p_cec_dev *cec = priv;
 135
 136         dev_dbg(cec->dev, "irq processing thread\n");
 137         switch (cec->tx) {
 138         case STATE_DONE:
 139                 cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
 140                 cec->tx = STATE_IDLE;
 141                 break;
 142         case STATE_NACK:
 143                 cec_transmit_done(cec->adap,
 144                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_NACK,
 145                         0, 1, 0, 0);
 146                 cec->tx = STATE_IDLE;
 147                 break;
 148         case STATE_ERROR:
 149                 cec_transmit_done(cec->adap,
 150                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_ERROR,
 151                         0, 0, 0, 1);
 152                 cec->tx = STATE_IDLE;
 153                 break;
 154         case STATE_BUSY:
 155                 dev_err(cec->dev, "state set to busy, this should not occur here\n");
 156                 break;
 157         default:
 158                 break;
 159         }
 160
 161         switch (cec->rx) {
 162         case STATE_DONE:
 163                 cec_received_msg(cec->adap, &cec->msg);
 164                 cec->rx = STATE_IDLE;
 165                 break;
 166         default:
 167                 break;
 168         }
 169
 170         return IRQ_HANDLED;
 171 }
 172
 173 static const struct cec_adap_ops s5p_cec_adap_ops = {
 174         .adap_enable = s5p_cec_adap_enable,
 175         .adap_log_addr = s5p_cec_adap_log_addr,
 176         .adap_transmit = s5p_cec_adap_transmit,
 177 };
 178
 179 static int s5p_cec_probe(struct platform_device *pdev)
 180 {
 181         struct device *dev = &pdev->dev;
 182         struct device *hdmi_dev;
 183         struct s5p_cec_dev *cec;
 184         bool needs_hpd = of_property_read_bool(pdev->dev.of_node, "needs-hpd");
 185         int ret;
 186
 187         hdmi_dev = cec_notifier_parse_hdmi_phandle(dev);
 188
 189         if (IS_ERR(hdmi_dev))
 190                 return PTR_ERR(hdmi_dev);
 191
 192         cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
 193         if (!cec)
 194                 return -ENOMEM;
 195
 196         cec->dev = dev;
 197
 198         cec->irq = platform_get_irq(pdev, 0);
 199         if (cec->irq < 0)
 200                 return cec->irq;
 201
 202         ret = devm_request_threaded_irq(dev, cec->irq, s5p_cec_irq_handler,
 203                 s5p_cec_irq_handler_thread, 0, pdev->name, cec);
 204         if (ret)
 205                 return ret;
 206
 207         cec->clk = devm_clk_get(dev, "hdmicec");
 208         if (IS_ERR(cec->clk))
 209                 return PTR_ERR(cec->clk);
 210
 211         cec->pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
 212                                                  "samsung,syscon-phandle");
 213         if (IS_ERR(cec->pmu))
 214                 return -EPROBE_DEFER;
 215
 216         cec->reg = devm_platform_ioremap_resource(pdev, 0);
 217         if (IS_ERR(cec->reg))
 218                 return PTR_ERR(cec->reg);
 219
 220         cec->adap = cec_allocate_adapter(&s5p_cec_adap_ops, cec, CEC_NAME,
 221                 CEC_CAP_DEFAULTS | (needs_hpd ? CEC_CAP_NEEDS_HPD : 0) |
 222                 CEC_CAP_CONNECTOR_INFO, 1);
 223         ret = PTR_ERR_OR_ZERO(cec->adap);
 224         if (ret)
 225                 return ret;
 226
 227         cec->notifier = cec_notifier_cec_adap_register(hdmi_dev, NULL,
 228                                                        cec->adap);
 229         if (!cec->notifier) {
 230                 ret = -ENOMEM;
 231                 goto err_delete_adapter;
 232         }
 233
 234         ret = cec_register_adapter(cec->adap, &pdev->dev);
 235         if (ret)
 236                 goto err_notifier;
 237
 238         platform_set_drvdata(pdev, cec);
 239         pm_runtime_enable(dev);
 240
 241         dev_dbg(dev, "successfully probed\n");
 242         return 0;
 243
 244 err_notifier:
 245         cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
 246
 247 err_delete_adapter:
 248         cec_delete_adapter(cec->adap);
 249         return ret;
 250 }
 251
 252 static void s5p_cec_remove(struct platform_device *pdev)
 253 {
 254         struct s5p_cec_dev *cec = platform_get_drvdata(pdev);
 255
 256         cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
 257         cec_unregister_adapter(cec->adap);
 258         pm_runtime_disable(&pdev->dev);
 259 }
 260
 261 static int __maybe_unused s5p_cec_runtime_suspend(struct device *dev)
 262 {
 263         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 264
 265         clk_disable_unprepare(cec->clk);
 266         return 0;
 267 }
 268
 269 static int __maybe_unused s5p_cec_runtime_resume(struct device *dev)
 270 {
 271         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 272         int ret;
 273
 274         ret = clk_prepare_enable(cec->clk);
 275         if (ret < 0)
 276                 return ret;
 277         return 0;
 278 }
 279
 280 static const struct dev_pm_ops s5p_cec_pm_ops = {
 281         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 282                                 pm_runtime_force_resume)
 283         SET_RUNTIME_PM_OPS(s5p_cec_runtime_suspend, s5p_cec_runtime_resume,
 284                            NULL)
 285 };
 286
 287 static const struct of_device_id s5p_cec_match[] = {
 288         {
 289                 .compatible     = "samsung,s5p-cec",
 290         },
 291         {},
 292 };
 293 MODULE_DEVICE_TABLE(of, s5p_cec_match);
 294
 295 static struct platform_driver s5p_cec_pdrv = {
 296         .probe  = s5p_cec_probe,
 297         .remove = s5p_cec_remove,
 298         .driver = {
 299                 .name           = CEC_NAME,
 300                 .of_match_table = s5p_cec_match,
 301                 .pm             = &s5p_cec_pm_ops,
 302         },
 303 };
 304
 305 module_platform_driver(s5p_cec_pdrv);
 306
 307 MODULE_AUTHOR("Kamil Debski <kamil@wypas.org>");
 308 MODULE_LICENSE("GPL");
 309 MODULE_DESCRIPTION("Samsung S5P CEC driver");