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
 32static int debug;
 33module_param(debug, int, 0644);
 34MODULE_PARM_DESC(debug, "debug level (0-2)");
 35
 36static 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
 63static 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
 71static 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
 84static 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
132static 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
173static 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
179static 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
244err_notifier:
245	cec_notifier_cec_adap_unregister(cec->notifier, cec->adap);
246
247err_delete_adapter:
248	cec_delete_adapter(cec->adap);
249	return ret;
250}
251
252static 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
261static 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
269static 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
280static 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
287static const struct of_device_id s5p_cec_match[] = {
288	{
289		.compatible	= "samsung,s5p-cec",
290	},
291	{},
292};
293MODULE_DEVICE_TABLE(of, s5p_cec_match);
294
295static 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
305module_platform_driver(s5p_cec_pdrv);
306
307MODULE_AUTHOR("Kamil Debski <kamil@wypas.org>");
308MODULE_LICENSE("GPL");
309MODULE_DESCRIPTION("Samsung S5P CEC driver");