// SPDX-License-Identifier: GPL-2.0 /* * STIH4xx CEC driver * Copyright (C) STMicroelectronics SA 2016 * */ #include #include #include #include #include #include #include #include #include #include #define CEC_NAME "stih-cec" /* CEC registers */ #define CEC_CLK_DIV 0x0 #define CEC_CTRL 0x4 #define CEC_IRQ_CTRL 0x8 #define CEC_STATUS 0xC #define CEC_EXT_STATUS 0x10 #define CEC_TX_CTRL 0x14 #define CEC_FREE_TIME_THRESH 0x18 #define CEC_BIT_TOUT_THRESH 0x1C #define CEC_BIT_PULSE_THRESH 0x20 #define CEC_DATA 0x24 #define CEC_TX_ARRAY_CTRL 0x28 #define CEC_CTRL2 0x2C #define CEC_TX_ERROR_STS 0x30 #define CEC_ADDR_TABLE 0x34 #define CEC_DATA_ARRAY_CTRL 0x38 #define CEC_DATA_ARRAY_STATUS 0x3C #define CEC_TX_DATA_BASE 0x40 #define CEC_TX_DATA_TOP 0x50 #define CEC_TX_DATA_SIZE 0x1 #define CEC_RX_DATA_BASE 0x54 #define CEC_RX_DATA_TOP 0x64 #define CEC_RX_DATA_SIZE 0x1 /* CEC_CTRL2 */ #define CEC_LINE_INACTIVE_EN BIT(0) #define CEC_AUTO_BUS_ERR_EN BIT(1) #define CEC_STOP_ON_ARB_ERR_EN BIT(2) #define CEC_TX_REQ_WAIT_EN BIT(3) /* CEC_DATA_ARRAY_CTRL */ #define CEC_TX_ARRAY_EN BIT(0) #define CEC_RX_ARRAY_EN BIT(1) #define CEC_TX_ARRAY_RESET BIT(2) #define CEC_RX_ARRAY_RESET BIT(3) #define CEC_TX_N_OF_BYTES_IRQ_EN BIT(4) #define CEC_TX_STOP_ON_NACK BIT(7) /* CEC_TX_ARRAY_CTRL */ #define CEC_TX_N_OF_BYTES 0x1F #define CEC_TX_START BIT(5) #define CEC_TX_AUTO_SOM_EN BIT(6) #define CEC_TX_AUTO_EOM_EN BIT(7) /* CEC_IRQ_CTRL */ #define CEC_TX_DONE_IRQ_EN BIT(0) #define CEC_ERROR_IRQ_EN BIT(2) #define CEC_RX_DONE_IRQ_EN BIT(3) #define CEC_RX_SOM_IRQ_EN BIT(4) #define CEC_RX_EOM_IRQ_EN BIT(5) #define CEC_FREE_TIME_IRQ_EN BIT(6) #define CEC_PIN_STS_IRQ_EN BIT(7) /* CEC_CTRL */ #define CEC_IN_FILTER_EN BIT(0) #define CEC_PWR_SAVE_EN BIT(1) #define CEC_EN BIT(4) #define CEC_ACK_CTRL BIT(5) #define CEC_RX_RESET_EN BIT(6) #define CEC_IGNORE_RX_ERROR BIT(7) /* CEC_STATUS */ #define CEC_TX_DONE_STS BIT(0) #define CEC_TX_ACK_GET_STS BIT(1) #define CEC_ERROR_STS BIT(2) #define CEC_RX_DONE_STS BIT(3) #define CEC_RX_SOM_STS BIT(4) #define CEC_RX_EOM_STS BIT(5) #define CEC_FREE_TIME_IRQ_STS BIT(6) #define CEC_PIN_STS BIT(7) #define CEC_SBIT_TOUT_STS BIT(8) #define CEC_DBIT_TOUT_STS BIT(9) #define CEC_LPULSE_ERROR_STS BIT(10) #define CEC_HPULSE_ERROR_STS BIT(11) #define CEC_TX_ERROR BIT(12) #define CEC_TX_ARB_ERROR BIT(13) #define CEC_RX_ERROR_MIN BIT(14) #define CEC_RX_ERROR_MAX BIT(15) /* Signal free time in bit periods (2.4ms) */ #define CEC_PRESENT_INIT_SFT 7 #define CEC_NEW_INIT_SFT 5 #define CEC_RETRANSMIT_SFT 3 /* Constants for CEC_BIT_TOUT_THRESH register */ #define CEC_SBIT_TOUT_47MS BIT(1) #define CEC_SBIT_TOUT_48MS (BIT(0) | BIT(1)) #define CEC_SBIT_TOUT_50MS BIT(2) #define CEC_DBIT_TOUT_27MS BIT(0) #define CEC_DBIT_TOUT_28MS BIT(1) #define CEC_DBIT_TOUT_29MS (BIT(0) | BIT(1)) /* Constants for CEC_BIT_PULSE_THRESH register */ #define CEC_BIT_LPULSE_03MS BIT(1) #define CEC_BIT_HPULSE_03MS BIT(3) /* Constants for CEC_DATA_ARRAY_STATUS register */ #define CEC_RX_N_OF_BYTES 0x1F #define CEC_TX_N_OF_BYTES_SENT BIT(5) #define CEC_RX_OVERRUN BIT(6) struct stih_cec { struct cec_adapter *adap; struct device *dev; struct clk *clk; void __iomem *regs; int irq; u32 irq_status; struct cec_notifier *notifier; }; static int stih_cec_adap_enable(struct cec_adapter *adap, bool enable) { struct stih_cec *cec = cec_get_drvdata(adap); if (enable) { /* The doc says (input TCLK_PERIOD * CEC_CLK_DIV) = 0.1ms */ unsigned long clk_freq = clk_get_rate(cec->clk); u32 cec_clk_div = clk_freq / 10000; writel(cec_clk_div, cec->regs + CEC_CLK_DIV); /* Configuration of the durations activating a timeout */ writel(CEC_SBIT_TOUT_47MS | (CEC_DBIT_TOUT_28MS << 4), cec->regs + CEC_BIT_TOUT_THRESH); /* Configuration of the smallest allowed duration for pulses */ writel(CEC_BIT_LPULSE_03MS | CEC_BIT_HPULSE_03MS, cec->regs + CEC_BIT_PULSE_THRESH); /* Minimum received bit period threshold */ writel(BIT(5) | BIT(7), cec->regs + CEC_TX_CTRL); /* Configuration of transceiver data arrays */ writel(CEC_TX_ARRAY_EN | CEC_RX_ARRAY_EN | CEC_TX_STOP_ON_NACK, cec->regs + CEC_DATA_ARRAY_CTRL); /* Configuration of the control bits for CEC Transceiver */ writel(CEC_IN_FILTER_EN | CEC_EN | CEC_RX_RESET_EN, cec->regs + CEC_CTRL); /* Clear logical addresses */ writel(0, cec->regs + CEC_ADDR_TABLE); /* Clear the status register */ writel(0x0, cec->regs + CEC_STATUS); /* Enable the interrupts */ writel(CEC_TX_DONE_IRQ_EN | CEC_RX_DONE_IRQ_EN | CEC_RX_SOM_IRQ_EN | CEC_RX_EOM_IRQ_EN | CEC_ERROR_IRQ_EN, cec->regs + CEC_IRQ_CTRL); } else { /* Clear logical addresses */ writel(0, cec->regs + CEC_ADDR_TABLE); /* Clear the status register */ writel(0x0, cec->regs + CEC_STATUS); /* Disable the interrupts */ writel(0, cec->regs + CEC_IRQ_CTRL); } return 0; } static int stih_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr) { struct stih_cec *cec = cec_get_drvdata(adap); u32 reg = readl(cec->regs + CEC_ADDR_TABLE); reg |= 1 << logical_addr; if (logical_addr == CEC_LOG_ADDR_INVALID) reg = 0; writel(reg, cec->regs + CEC_ADDR_TABLE); return 0; } static int stih_cec_adap_transmit(struct cec_adapter *adap, u8 attempts, u32 signal_free_time, struct cec_msg *msg) { struct stih_cec *cec = cec_get_drvdata(adap); int i; /* Copy message into registers */ for (i = 0; i < msg->len; i++) writeb(msg->msg[i], cec->regs + CEC_TX_DATA_BASE + i); /* * Start transmission, configure hardware to add start and stop bits * Signal free time is handled by the hardware */ writel(CEC_TX_AUTO_SOM_EN | CEC_TX_AUTO_EOM_EN | CEC_TX_START | msg->len, cec->regs + CEC_TX_ARRAY_CTRL); return 0; } static void stih_tx_done(struct stih_cec *cec, u32 status) { if (status & CEC_TX_ERROR) { cec_transmit_attempt_done(cec->adap, CEC_TX_STATUS_ERROR); return; } if (status & CEC_TX_ARB_ERROR) { cec_transmit_attempt_done(cec->adap, CEC_TX_STATUS_ARB_LOST); return; } if (!(status & CEC_TX_ACK_GET_STS)) { cec_transmit_attempt_done(cec->adap, CEC_TX_STATUS_NACK); return; } cec_transmit_attempt_done(cec->adap, CEC_TX_STATUS_OK); } static void stih_rx_done(struct stih_cec *cec, u32 status) { struct cec_msg msg = {}; u8 i; if (status & CEC_RX_ERROR_MIN) return; if (status & CEC_RX_ERROR_MAX) return; msg.len = readl(cec->regs + CEC_DATA_ARRAY_STATUS) & 0x1f; if (!msg.len) return; if (msg.len > 16) msg.len = 16; for (i = 0; i < msg.len; i++) msg.msg[i] = readl(cec->regs + CEC_RX_DATA_BASE + i); cec_received_msg(cec->adap, &msg); } static irqreturn_t stih_cec_irq_handler_thread(int irq, void *priv) { struct stih_cec *cec = priv; if (cec->irq_status & CEC_TX_DONE_STS) stih_tx_done(cec, cec->irq_status); if (cec->irq_status & CEC_RX_DONE_STS) stih_rx_done(cec, cec->irq_status); cec->irq_status = 0; return IRQ_HANDLED; } static irqreturn_t stih_cec_irq_handler(int irq, void *priv) { struct stih_cec *cec = priv; cec->irq_status = readl(cec->regs + CEC_STATUS); writel(cec->irq_status, cec->regs + CEC_STATUS); return IRQ_WAKE_THREAD; } static const struct cec_adap_ops sti_cec_adap_ops = { .adap_enable = stih_cec_adap_enable, .adap_log_addr = stih_cec_adap_log_addr, .adap_transmit = stih_cec_adap_transmit, }; static int stih_cec_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct resource *res; struct stih_cec *cec; struct device_node *np; struct platform_device *hdmi_dev; int ret; cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL); if (!cec) return -ENOMEM; np = of_parse_phandle(pdev->dev.of_node, "hdmi-phandle", 0); if (!np) { dev_err(&pdev->dev, "Failed to find hdmi node in device tree\n"); return -ENODEV; } hdmi_dev = of_find_device_by_node(np); if (!hdmi_dev) return -EPROBE_DEFER; cec->notifier = cec_notifier_get(&hdmi_dev->dev); if (!cec->notifier) return -ENOMEM; cec->dev = dev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); cec->regs = devm_ioremap_resource(dev, res); if (IS_ERR(cec->regs)) return PTR_ERR(cec->regs); cec->irq = platform_get_irq(pdev, 0); if (cec->irq < 0) return cec->irq; ret = devm_request_threaded_irq(dev, cec->irq, stih_cec_irq_handler, stih_cec_irq_handler_thread, 0, pdev->name, cec); if (ret) return ret; cec->clk = devm_clk_get(dev, "cec-clk"); if (IS_ERR(cec->clk)) { dev_err(dev, "Cannot get cec clock\n"); return PTR_ERR(cec->clk); } cec->adap = cec_allocate_adapter(&sti_cec_adap_ops, cec, CEC_NAME, CEC_CAP_DEFAULTS, CEC_MAX_LOG_ADDRS); ret = PTR_ERR_OR_ZERO(cec->adap); if (ret) return ret; ret = cec_register_adapter(cec->adap, &pdev->dev); if (ret) { cec_delete_adapter(cec->adap); return ret; } cec_register_cec_notifier(cec->adap, cec->notifier); platform_set_drvdata(pdev, cec); return 0; } static int stih_cec_remove(struct platform_device *pdev) { struct stih_cec *cec = platform_get_drvdata(pdev); cec_unregister_adapter(cec->adap); cec_notifier_put(cec->notifier); return 0; } static const struct of_device_id stih_cec_match[] = { { .compatible = "st,stih-cec", }, {}, }; MODULE_DEVICE_TABLE(of, stih_cec_match); static struct platform_driver stih_cec_pdrv = { .probe = stih_cec_probe, .remove = stih_cec_remove, .driver = { .name = CEC_NAME, .of_match_table = stih_cec_match, }, }; module_platform_driver(stih_cec_pdrv); MODULE_AUTHOR("Benjamin Gaignard "); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("STIH4xx CEC driver");