drivers/media/platform/s5p-cec/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         struct s5p_cec_dev *cec = cec_get_drvdata(adap);
  39
  40         if (enable) {
  41                 pm_runtime_get_sync(cec->dev);
  42
  43                 s5p_cec_reset(cec);
  44
  45                 s5p_cec_set_divider(cec);
  46                 s5p_cec_threshold(cec);
  47
  48                 s5p_cec_unmask_tx_interrupts(cec);
  49                 s5p_cec_unmask_rx_interrupts(cec);
  50                 s5p_cec_enable_rx(cec);
  51         } else {
  52                 s5p_cec_mask_tx_interrupts(cec);
  53                 s5p_cec_mask_rx_interrupts(cec);
  54                 pm_runtime_disable(cec->dev);
  55         }
  56
  57         return 0;
  58 }
  59
  60 static int s5p_cec_adap_log_addr(struct cec_adapter *adap, u8 addr)
  61 {
  62         struct s5p_cec_dev *cec = cec_get_drvdata(adap);
  63
  64         s5p_cec_set_addr(cec, addr);
  65         return 0;
  66 }
  67
  68 static int s5p_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
  69                                  u32 signal_free_time, struct cec_msg *msg)
  70 {
  71         struct s5p_cec_dev *cec = cec_get_drvdata(adap);
  72
  73         /*
  74          * Unclear if 0 retries are allowed by the hardware, so have 1 as
  75          * the minimum.
  76          */
  77         s5p_cec_copy_packet(cec, msg->msg, msg->len, max(1, attempts - 1));
  78         return 0;
  79 }
  80
  81 static irqreturn_t s5p_cec_irq_handler(int irq, void *priv)
  82 {
  83         struct s5p_cec_dev *cec = priv;
  84         u32 status = 0;
  85
  86         status = s5p_cec_get_status(cec);
  87
  88         dev_dbg(cec->dev, "irq received\n");
  89
  90         if (status & CEC_STATUS_TX_DONE) {
  91                 if (status & CEC_STATUS_TX_NACK) {
  92                         dev_dbg(cec->dev, "CEC_STATUS_TX_NACK set\n");
  93                         cec->tx = STATE_NACK;
  94                 } else 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                         cec->msg.rx_status = CEC_RX_STATUS_OK;
 116                         s5p_cec_get_rx_buf(cec, cec->msg.len,
 117                                         cec->msg.msg);
 118                         cec->rx = STATE_DONE;
 119                         s5p_cec_enable_rx(cec);
 120                 }
 121                 /* Clear interrupt pending bit */
 122                 s5p_clr_pending_rx(cec);
 123         }
 124         return IRQ_WAKE_THREAD;
 125 }
 126
 127 static irqreturn_t s5p_cec_irq_handler_thread(int irq, void *priv)
 128 {
 129         struct s5p_cec_dev *cec = priv;
 130
 131         dev_dbg(cec->dev, "irq processing thread\n");
 132         switch (cec->tx) {
 133         case STATE_DONE:
 134                 cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
 135                 cec->tx = STATE_IDLE;
 136                 break;
 137         case STATE_NACK:
 138                 cec_transmit_done(cec->adap,
 139                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_NACK,
 140                         0, 1, 0, 0);
 141                 cec->tx = STATE_IDLE;
 142                 break;
 143         case STATE_ERROR:
 144                 cec_transmit_done(cec->adap,
 145                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_ERROR,
 146                         0, 0, 0, 1);
 147                 cec->tx = STATE_IDLE;
 148                 break;
 149         case STATE_BUSY:
 150                 dev_err(cec->dev, "state set to busy, this should not occur here\n");
 151                 break;
 152         default:
 153                 break;
 154         }
 155
 156         switch (cec->rx) {
 157         case STATE_DONE:
 158                 cec_received_msg(cec->adap, &cec->msg);
 159                 cec->rx = STATE_IDLE;
 160                 break;
 161         default:
 162                 break;
 163         }
 164
 165         return IRQ_HANDLED;
 166 }
 167
 168 static const struct cec_adap_ops s5p_cec_adap_ops = {
 169         .adap_enable = s5p_cec_adap_enable,
 170         .adap_log_addr = s5p_cec_adap_log_addr,
 171         .adap_transmit = s5p_cec_adap_transmit,
 172 };
 173
 174 static int s5p_cec_probe(struct platform_device *pdev)
 175 {
 176         struct device *dev = &pdev->dev;
 177         struct device *hdmi_dev;
 178         struct resource *res;
 179         struct s5p_cec_dev *cec;
 180         bool needs_hpd = of_property_read_bool(pdev->dev.of_node, "needs-hpd");
 181         int ret;
 182
 183         hdmi_dev = cec_notifier_parse_hdmi_phandle(dev);
 184
 185         if (IS_ERR(hdmi_dev))
 186                 return PTR_ERR(hdmi_dev);
 187
 188         cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
 189         if (!cec)
 190                 return -ENOMEM;
 191
 192         cec->dev = dev;
 193
 194         cec->irq = platform_get_irq(pdev, 0);
 195         if (cec->irq < 0)
 196                 return cec->irq;
 197
 198         ret = devm_request_threaded_irq(dev, cec->irq, s5p_cec_irq_handler,
 199                 s5p_cec_irq_handler_thread, 0, pdev->name, cec);
 200         if (ret)
 201                 return ret;
 202
 203         cec->clk = devm_clk_get(dev, "hdmicec");
 204         if (IS_ERR(cec->clk))
 205                 return PTR_ERR(cec->clk);
 206
 207         cec->pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
 208                                                  "samsung,syscon-phandle");
 209         if (IS_ERR(cec->pmu))
 210                 return -EPROBE_DEFER;
 211
 212         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 213         cec->reg = devm_ioremap_resource(dev, res);
 214         if (IS_ERR(cec->reg))
 215                 return PTR_ERR(cec->reg);
 216
 217         cec->adap = cec_allocate_adapter(&s5p_cec_adap_ops, cec, CEC_NAME,
 218                 CEC_CAP_DEFAULTS | (needs_hpd ? CEC_CAP_NEEDS_HPD : 0) |
 219                 CEC_CAP_CONNECTOR_INFO, 1);
 220         ret = PTR_ERR_OR_ZERO(cec->adap);
 221         if (ret)
 222                 return ret;
 223
 224         cec->notifier = cec_notifier_cec_adap_register(hdmi_dev, NULL,
 225                                                        cec->adap);
 226         if (!cec->notifier) {
 227                 ret = -ENOMEM;
 228                 goto err_delete_adapter;
 229         }
 230
 231         ret = cec_register_adapter(cec->adap, &pdev->dev);
 232         if (ret)
 233                 goto err_notifier;
 234
 235         platform_set_drvdata(pdev, cec);
 236         pm_runtime_enable(dev);
 237
 238         dev_dbg(dev, "successfully probed\n");
 239         return 0;
 240
 241 err_notifier:
 242         cec_notifier_cec_adap_unregister(cec->notifier);
 243
 244 err_delete_adapter:
 245         cec_delete_adapter(cec->adap);
 246         return ret;
 247 }
 248
 249 static int s5p_cec_remove(struct platform_device *pdev)
 250 {
 251         struct s5p_cec_dev *cec = platform_get_drvdata(pdev);
 252
 253         cec_notifier_cec_adap_unregister(cec->notifier);
 254         cec_unregister_adapter(cec->adap);
 255         pm_runtime_disable(&pdev->dev);
 256         return 0;
 257 }
 258
 259 static int __maybe_unused s5p_cec_runtime_suspend(struct device *dev)
 260 {
 261         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 262
 263         clk_disable_unprepare(cec->clk);
 264         return 0;
 265 }
 266
 267 static int __maybe_unused s5p_cec_runtime_resume(struct device *dev)
 268 {
 269         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 270         int ret;
 271
 272         ret = clk_prepare_enable(cec->clk);
 273         if (ret < 0)
 274                 return ret;
 275         return 0;
 276 }
 277
 278 static const struct dev_pm_ops s5p_cec_pm_ops = {
 279         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 280                                 pm_runtime_force_resume)
 281         SET_RUNTIME_PM_OPS(s5p_cec_runtime_suspend, s5p_cec_runtime_resume,
 282                            NULL)
 283 };
 284
 285 static const struct of_device_id s5p_cec_match[] = {
 286         {
 287                 .compatible     = "samsung,s5p-cec",
 288         },
 289         {},
 290 };
 291 MODULE_DEVICE_TABLE(of, s5p_cec_match);
 292
 293 static struct platform_driver s5p_cec_pdrv = {
 294         .probe  = s5p_cec_probe,
 295         .remove = s5p_cec_remove,
 296         .driver = {
 297                 .name           = CEC_NAME,
 298                 .of_match_table = s5p_cec_match,
 299                 .pm             = &s5p_cec_pm_ops,
 300         },
 301 };
 302
 303 module_platform_driver(s5p_cec_pdrv);
 304
 305 MODULE_AUTHOR("Kamil Debski <kamil@wypas.org>");
 306 MODULE_LICENSE("GPL");
 307 MODULE_DESCRIPTION("Samsung S5P CEC driver");