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