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                         cec->msg.rx_status = CEC_RX_STATUS_OK;
 119                         s5p_cec_get_rx_buf(cec, cec->msg.len,
 120                                         cec->msg.msg);
 121                         cec->rx = STATE_DONE;
 122                         s5p_cec_enable_rx(cec);
 123                 }
 124                 /* Clear interrupt pending bit */
 125                 s5p_clr_pending_rx(cec);
 126         }
 127         return IRQ_WAKE_THREAD;
 128 }
 129
 130 static irqreturn_t s5p_cec_irq_handler_thread(int irq, void *priv)
 131 {
 132         struct s5p_cec_dev *cec = priv;
 133
 134         dev_dbg(cec->dev, "irq processing thread\n");
 135         switch (cec->tx) {
 136         case STATE_DONE:
 137                 cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
 138                 cec->tx = STATE_IDLE;
 139                 break;
 140         case STATE_NACK:
 141                 cec_transmit_done(cec->adap,
 142                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_NACK,
 143                         0, 1, 0, 0);
 144                 cec->tx = STATE_IDLE;
 145                 break;
 146         case STATE_ERROR:
 147                 cec_transmit_done(cec->adap,
 148                         CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_ERROR,
 149                         0, 0, 0, 1);
 150                 cec->tx = STATE_IDLE;
 151                 break;
 152         case STATE_BUSY:
 153                 dev_err(cec->dev, "state set to busy, this should not occur here\n");
 154                 break;
 155         default:
 156                 break;
 157         }
 158
 159         switch (cec->rx) {
 160         case STATE_DONE:
 161                 cec_received_msg(cec->adap, &cec->msg);
 162                 cec->rx = STATE_IDLE;
 163                 break;
 164         default:
 165                 break;
 166         }
 167
 168         return IRQ_HANDLED;
 169 }
 170
 171 static const struct cec_adap_ops s5p_cec_adap_ops = {
 172         .adap_enable = s5p_cec_adap_enable,
 173         .adap_log_addr = s5p_cec_adap_log_addr,
 174         .adap_transmit = s5p_cec_adap_transmit,
 175 };
 176
 177 static int s5p_cec_probe(struct platform_device *pdev)
 178 {
 179         struct device *dev = &pdev->dev;
 180         struct device *hdmi_dev;
 181         struct s5p_cec_dev *cec;
 182         bool needs_hpd = of_property_read_bool(pdev->dev.of_node, "needs-hpd");
 183         int ret;
 184
 185         hdmi_dev = cec_notifier_parse_hdmi_phandle(dev);
 186
 187         if (IS_ERR(hdmi_dev))
 188                 return PTR_ERR(hdmi_dev);
 189
 190         cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
 191         if (!cec)
 192                 return -ENOMEM;
 193
 194         cec->dev = dev;
 195
 196         cec->irq = platform_get_irq(pdev, 0);
 197         if (cec->irq < 0)
 198                 return cec->irq;
 199
 200         ret = devm_request_threaded_irq(dev, cec->irq, s5p_cec_irq_handler,
 201                 s5p_cec_irq_handler_thread, 0, pdev->name, cec);
 202         if (ret)
 203                 return ret;
 204
 205         cec->clk = devm_clk_get(dev, "hdmicec");
 206         if (IS_ERR(cec->clk))
 207                 return PTR_ERR(cec->clk);
 208
 209         cec->pmu = syscon_regmap_lookup_by_phandle(dev->of_node,
 210                                                  "samsung,syscon-phandle");
 211         if (IS_ERR(cec->pmu))
 212                 return -EPROBE_DEFER;
 213
 214         cec->reg = devm_platform_ioremap_resource(pdev, 0);
 215         if (IS_ERR(cec->reg))
 216                 return PTR_ERR(cec->reg);
 217
 218         cec->adap = cec_allocate_adapter(&s5p_cec_adap_ops, cec, CEC_NAME,
 219                 CEC_CAP_DEFAULTS | (needs_hpd ? CEC_CAP_NEEDS_HPD : 0) |
 220                 CEC_CAP_CONNECTOR_INFO, 1);
 221         ret = PTR_ERR_OR_ZERO(cec->adap);
 222         if (ret)
 223                 return ret;
 224
 225         cec->notifier = cec_notifier_cec_adap_register(hdmi_dev, NULL,
 226                                                        cec->adap);
 227         if (!cec->notifier) {
 228                 ret = -ENOMEM;
 229                 goto err_delete_adapter;
 230         }
 231
 232         ret = cec_register_adapter(cec->adap, &pdev->dev);
 233         if (ret)
 234                 goto err_notifier;
 235
 236         platform_set_drvdata(pdev, cec);
 237         pm_runtime_enable(dev);
 238
 239         dev_dbg(dev, "successfully probed\n");
 240         return 0;
 241
 242 err_notifier:
 243         cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
 244
 245 err_delete_adapter:
 246         cec_delete_adapter(cec->adap);
 247         return ret;
 248 }
 249
 250 static int s5p_cec_remove(struct platform_device *pdev)
 251 {
 252         struct s5p_cec_dev *cec = platform_get_drvdata(pdev);
 253
 254         cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
 255         cec_unregister_adapter(cec->adap);
 256         pm_runtime_disable(&pdev->dev);
 257         return 0;
 258 }
 259
 260 static int __maybe_unused s5p_cec_runtime_suspend(struct device *dev)
 261 {
 262         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 263
 264         clk_disable_unprepare(cec->clk);
 265         return 0;
 266 }
 267
 268 static int __maybe_unused s5p_cec_runtime_resume(struct device *dev)
 269 {
 270         struct s5p_cec_dev *cec = dev_get_drvdata(dev);
 271         int ret;
 272
 273         ret = clk_prepare_enable(cec->clk);
 274         if (ret < 0)
 275                 return ret;
 276         return 0;
 277 }
 278
 279 static const struct dev_pm_ops s5p_cec_pm_ops = {
 280         SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
 281                                 pm_runtime_force_resume)
 282         SET_RUNTIME_PM_OPS(s5p_cec_runtime_suspend, s5p_cec_runtime_resume,
 283                            NULL)
 284 };
 285
 286 static const struct of_device_id s5p_cec_match[] = {
 287         {
 288                 .compatible     = "samsung,s5p-cec",
 289         },
 290         {},
 291 };
 292 MODULE_DEVICE_TABLE(of, s5p_cec_match);
 293
 294 static struct platform_driver s5p_cec_pdrv = {
 295         .probe  = s5p_cec_probe,
 296         .remove = s5p_cec_remove,
 297         .driver = {
 298                 .name           = CEC_NAME,
 299                 .of_match_table = s5p_cec_match,
 300                 .pm             = &s5p_cec_pm_ops,
 301         },
 302 };
 303
 304 module_platform_driver(s5p_cec_pdrv);
 305
 306 MODULE_AUTHOR("Kamil Debski <kamil@wypas.org>");
 307 MODULE_LICENSE("GPL");
 308 MODULE_DESCRIPTION("Samsung S5P CEC driver");