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 int 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 return 0; 260 } 261 262 static int __maybe_unused s5p_cec_runtime_suspend(struct device *dev) 263 { 264 struct s5p_cec_dev *cec = dev_get_drvdata(dev); 265 266 clk_disable_unprepare(cec->clk); 267 return 0; 268 } 269 270 static int __maybe_unused s5p_cec_runtime_resume(struct device *dev) 271 { 272 struct s5p_cec_dev *cec = dev_get_drvdata(dev); 273 int ret; 274 275 ret = clk_prepare_enable(cec->clk); 276 if (ret < 0) 277 return ret; 278 return 0; 279 } 280 281 static const struct dev_pm_ops s5p_cec_pm_ops = { 282 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 283 pm_runtime_force_resume) 284 SET_RUNTIME_PM_OPS(s5p_cec_runtime_suspend, s5p_cec_runtime_resume, 285 NULL) 286 }; 287 288 static const struct of_device_id s5p_cec_match[] = { 289 { 290 .compatible = "samsung,s5p-cec", 291 }, 292 {}, 293 }; 294 MODULE_DEVICE_TABLE(of, s5p_cec_match); 295 296 static struct platform_driver s5p_cec_pdrv = { 297 .probe = s5p_cec_probe, 298 .remove = s5p_cec_remove, 299 .driver = { 300 .name = CEC_NAME, 301 .of_match_table = s5p_cec_match, 302 .pm = &s5p_cec_pm_ops, 303 }, 304 }; 305 306 module_platform_driver(s5p_cec_pdrv); 307 308 MODULE_AUTHOR("Kamil Debski <kamil@wypas.org>"); 309 MODULE_LICENSE("GPL"); 310 MODULE_DESCRIPTION("Samsung S5P CEC driver"); 311