1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) 2014 MediaTek Inc.
4 * Author: Jie Qiu <jie.qiu@mediatek.com>
5 */
6 #include <linux/clk.h>
7 #include <linux/delay.h>
8 #include <linux/io.h>
9 #include <linux/interrupt.h>
10 #include <linux/mod_devicetable.h>
11 #include <linux/platform_device.h>
12
13 #include "mtk_cec.h"
14
15 #define TR_CONFIG 0x00
16 #define CLEAR_CEC_IRQ BIT(15)
17
18 #define CEC_CKGEN 0x04
19 #define CEC_32K_PDN BIT(19)
20 #define PDN BIT(16)
21
22 #define RX_EVENT 0x54
23 #define HDMI_PORD BIT(25)
24 #define HDMI_HTPLG BIT(24)
25 #define HDMI_PORD_INT_EN BIT(9)
26 #define HDMI_HTPLG_INT_EN BIT(8)
27
28 #define RX_GEN_WD 0x58
29 #define HDMI_PORD_INT_32K_STATUS BIT(26)
30 #define RX_RISC_INT_32K_STATUS BIT(25)
31 #define HDMI_HTPLG_INT_32K_STATUS BIT(24)
32 #define HDMI_PORD_INT_32K_CLR BIT(18)
33 #define RX_INT_32K_CLR BIT(17)
34 #define HDMI_HTPLG_INT_32K_CLR BIT(16)
35 #define HDMI_PORD_INT_32K_STA_MASK BIT(10)
36 #define RX_RISC_INT_32K_STA_MASK BIT(9)
37 #define HDMI_HTPLG_INT_32K_STA_MASK BIT(8)
38 #define HDMI_PORD_INT_32K_EN BIT(2)
39 #define RX_INT_32K_EN BIT(1)
40 #define HDMI_HTPLG_INT_32K_EN BIT(0)
41
42 #define NORMAL_INT_CTRL 0x5C
43 #define HDMI_HTPLG_INT_STA BIT(0)
44 #define HDMI_PORD_INT_STA BIT(1)
45 #define HDMI_HTPLG_INT_CLR BIT(16)
46 #define HDMI_PORD_INT_CLR BIT(17)
47 #define HDMI_FULL_INT_CLR BIT(20)
48
49 struct mtk_cec {
50 void __iomem *regs;
51 struct clk *clk;
52 int irq;
53 bool hpd;
54 void (*hpd_event)(bool hpd, struct device *dev);
55 struct device *hdmi_dev;
56 spinlock_t lock;
57 };
58
mtk_cec_clear_bits(struct mtk_cec * cec,unsigned int offset,unsigned int bits)59 static void mtk_cec_clear_bits(struct mtk_cec *cec, unsigned int offset,
60 unsigned int bits)
61 {
62 void __iomem *reg = cec->regs + offset;
63 u32 tmp;
64
65 tmp = readl(reg);
66 tmp &= ~bits;
67 writel(tmp, reg);
68 }
69
mtk_cec_set_bits(struct mtk_cec * cec,unsigned int offset,unsigned int bits)70 static void mtk_cec_set_bits(struct mtk_cec *cec, unsigned int offset,
71 unsigned int bits)
72 {
73 void __iomem *reg = cec->regs + offset;
74 u32 tmp;
75
76 tmp = readl(reg);
77 tmp |= bits;
78 writel(tmp, reg);
79 }
80
mtk_cec_mask(struct mtk_cec * cec,unsigned int offset,unsigned int val,unsigned int mask)81 static void mtk_cec_mask(struct mtk_cec *cec, unsigned int offset,
82 unsigned int val, unsigned int mask)
83 {
84 u32 tmp = readl(cec->regs + offset) & ~mask;
85
86 tmp |= val & mask;
87 writel(val, cec->regs + offset);
88 }
89
mtk_cec_set_hpd_event(struct device * dev,void (* hpd_event)(bool hpd,struct device * dev),struct device * hdmi_dev)90 void mtk_cec_set_hpd_event(struct device *dev,
91 void (*hpd_event)(bool hpd, struct device *dev),
92 struct device *hdmi_dev)
93 {
94 struct mtk_cec *cec = dev_get_drvdata(dev);
95 unsigned long flags;
96
97 spin_lock_irqsave(&cec->lock, flags);
98 cec->hdmi_dev = hdmi_dev;
99 cec->hpd_event = hpd_event;
100 spin_unlock_irqrestore(&cec->lock, flags);
101 }
102
mtk_cec_hpd_high(struct device * dev)103 bool mtk_cec_hpd_high(struct device *dev)
104 {
105 struct mtk_cec *cec = dev_get_drvdata(dev);
106 unsigned int status;
107
108 status = readl(cec->regs + RX_EVENT);
109
110 return (status & (HDMI_PORD | HDMI_HTPLG)) == (HDMI_PORD | HDMI_HTPLG);
111 }
112
mtk_cec_htplg_irq_init(struct mtk_cec * cec)113 static void mtk_cec_htplg_irq_init(struct mtk_cec *cec)
114 {
115 mtk_cec_mask(cec, CEC_CKGEN, 0 | CEC_32K_PDN, PDN | CEC_32K_PDN);
116 mtk_cec_set_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
117 RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
118 mtk_cec_mask(cec, RX_GEN_WD, 0, HDMI_PORD_INT_32K_CLR | RX_INT_32K_CLR |
119 HDMI_HTPLG_INT_32K_CLR | HDMI_PORD_INT_32K_EN |
120 RX_INT_32K_EN | HDMI_HTPLG_INT_32K_EN);
121 }
122
mtk_cec_htplg_irq_enable(struct mtk_cec * cec)123 static void mtk_cec_htplg_irq_enable(struct mtk_cec *cec)
124 {
125 mtk_cec_set_bits(cec, RX_EVENT, HDMI_PORD_INT_EN | HDMI_HTPLG_INT_EN);
126 }
127
mtk_cec_htplg_irq_disable(struct mtk_cec * cec)128 static void mtk_cec_htplg_irq_disable(struct mtk_cec *cec)
129 {
130 mtk_cec_clear_bits(cec, RX_EVENT, HDMI_PORD_INT_EN | HDMI_HTPLG_INT_EN);
131 }
132
mtk_cec_clear_htplg_irq(struct mtk_cec * cec)133 static void mtk_cec_clear_htplg_irq(struct mtk_cec *cec)
134 {
135 mtk_cec_set_bits(cec, TR_CONFIG, CLEAR_CEC_IRQ);
136 mtk_cec_set_bits(cec, NORMAL_INT_CTRL, HDMI_HTPLG_INT_CLR |
137 HDMI_PORD_INT_CLR | HDMI_FULL_INT_CLR);
138 mtk_cec_set_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
139 RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
140 usleep_range(5, 10);
141 mtk_cec_clear_bits(cec, NORMAL_INT_CTRL, HDMI_HTPLG_INT_CLR |
142 HDMI_PORD_INT_CLR | HDMI_FULL_INT_CLR);
143 mtk_cec_clear_bits(cec, TR_CONFIG, CLEAR_CEC_IRQ);
144 mtk_cec_clear_bits(cec, RX_GEN_WD, HDMI_PORD_INT_32K_CLR |
145 RX_INT_32K_CLR | HDMI_HTPLG_INT_32K_CLR);
146 }
147
mtk_cec_hpd_event(struct mtk_cec * cec,bool hpd)148 static void mtk_cec_hpd_event(struct mtk_cec *cec, bool hpd)
149 {
150 void (*hpd_event)(bool hpd, struct device *dev);
151 struct device *hdmi_dev;
152 unsigned long flags;
153
154 spin_lock_irqsave(&cec->lock, flags);
155 hpd_event = cec->hpd_event;
156 hdmi_dev = cec->hdmi_dev;
157 spin_unlock_irqrestore(&cec->lock, flags);
158
159 if (hpd_event)
160 hpd_event(hpd, hdmi_dev);
161 }
162
mtk_cec_htplg_isr_thread(int irq,void * arg)163 static irqreturn_t mtk_cec_htplg_isr_thread(int irq, void *arg)
164 {
165 struct device *dev = arg;
166 struct mtk_cec *cec = dev_get_drvdata(dev);
167 bool hpd;
168
169 mtk_cec_clear_htplg_irq(cec);
170 hpd = mtk_cec_hpd_high(dev);
171
172 if (cec->hpd != hpd) {
173 dev_dbg(dev, "hotplug event! cur hpd = %d, hpd = %d\n",
174 cec->hpd, hpd);
175 cec->hpd = hpd;
176 mtk_cec_hpd_event(cec, hpd);
177 }
178 return IRQ_HANDLED;
179 }
180
mtk_cec_probe(struct platform_device * pdev)181 static int mtk_cec_probe(struct platform_device *pdev)
182 {
183 struct device *dev = &pdev->dev;
184 struct mtk_cec *cec;
185 struct resource *res;
186 int ret;
187
188 cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
189 if (!cec)
190 return -ENOMEM;
191
192 platform_set_drvdata(pdev, cec);
193 spin_lock_init(&cec->lock);
194
195 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
196 cec->regs = devm_ioremap_resource(dev, res);
197 if (IS_ERR(cec->regs)) {
198 ret = PTR_ERR(cec->regs);
199 dev_err(dev, "Failed to ioremap cec: %d\n", ret);
200 return ret;
201 }
202
203 cec->clk = devm_clk_get(dev, NULL);
204 if (IS_ERR(cec->clk)) {
205 ret = PTR_ERR(cec->clk);
206 dev_err(dev, "Failed to get cec clock: %d\n", ret);
207 return ret;
208 }
209
210 cec->irq = platform_get_irq(pdev, 0);
211 if (cec->irq < 0) {
212 dev_err(dev, "Failed to get cec irq: %d\n", cec->irq);
213 return cec->irq;
214 }
215
216 ret = devm_request_threaded_irq(dev, cec->irq, NULL,
217 mtk_cec_htplg_isr_thread,
218 IRQF_SHARED | IRQF_TRIGGER_LOW |
219 IRQF_ONESHOT, "hdmi hpd", dev);
220 if (ret) {
221 dev_err(dev, "Failed to register cec irq: %d\n", ret);
222 return ret;
223 }
224
225 ret = clk_prepare_enable(cec->clk);
226 if (ret) {
227 dev_err(dev, "Failed to enable cec clock: %d\n", ret);
228 return ret;
229 }
230
231 mtk_cec_htplg_irq_init(cec);
232 mtk_cec_htplg_irq_enable(cec);
233
234 return 0;
235 }
236
mtk_cec_remove(struct platform_device * pdev)237 static int mtk_cec_remove(struct platform_device *pdev)
238 {
239 struct mtk_cec *cec = platform_get_drvdata(pdev);
240
241 mtk_cec_htplg_irq_disable(cec);
242 clk_disable_unprepare(cec->clk);
243 return 0;
244 }
245
246 static const struct of_device_id mtk_cec_of_ids[] = {
247 { .compatible = "mediatek,mt8173-cec", },
248 {}
249 };
250
251 struct platform_driver mtk_cec_driver = {
252 .probe = mtk_cec_probe,
253 .remove = mtk_cec_remove,
254 .driver = {
255 .name = "mediatek-cec",
256 .of_match_table = mtk_cec_of_ids,
257 },
258 };
259
