// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2025 Renesas Electronics Corp. */ #include #include #include #include #include #include #include #include #include "serial_mctrl_gpio.h" #include "rsci.h" MODULE_IMPORT_NS("SH_SCI"); /* RSCI registers */ #define RDR 0x00 #define TDR 0x04 #define CCR0 0x08 #define CCR1 0x0C #define CCR2 0x10 #define CCR3 0x14 #define CCR4 0x18 #define FCR 0x24 #define CSR 0x48 #define FRSR 0x50 #define FTSR 0x54 #define CFCLR 0x68 #define FFCLR 0x70 /* RDR (Receive Data Register) */ #define RDR_FFER BIT(12) /* FIFO Framing Error */ #define RDR_FPER BIT(11) /* FIFO Parity Error */ #define RDR_RDAT_MSK GENMASK(8, 0) /* CCR0 (Common Control Register 0) */ #define CCR0_SSE BIT(24) /* SSn# Pin Function Enable */ #define CCR0_TEIE BIT(21) /* Transmit End Interrupt Enable */ #define CCR0_TIE BIT(20) /* Transmit Interrupt Enable */ #define CCR0_RIE BIT(16) /* Receive Interrupt Enable */ #define CCR0_IDSEL BIT(10) /* ID Frame Select */ #define CCR0_DCME BIT(9) /* Data Compare Match Enable */ #define CCR0_MPIE BIT(8) /* Multiprocessor Interrupt Enable */ #define CCR0_TE BIT(4) /* Transmit Enable */ #define CCR0_RE BIT(0) /* Receive Enable */ /* CCR1 (Common Control Register 1) */ #define CCR1_NFEN BIT(28) /* Digital Noise Filter Function */ #define CCR1_SHARPS BIT(20) /* Half -duplex Communication Select */ #define CCR1_SPLP BIT(16) /* Loopback Control */ #define CCR1_RINV BIT(13) /* RxD invert */ #define CCR1_TINV BIT(12) /* TxD invert */ #define CCR1_PM BIT(9) /* Parity Mode */ #define CCR1_PE BIT(8) /* Parity Enable */ #define CCR1_SPB2IO BIT(5) /* Serial Port Break I/O */ #define CCR1_SPB2DT BIT(4) /* Serial Port Break Data Select */ #define CCR1_CTSPEN BIT(1) /* CTS External Pin Enable */ #define CCR1_CTSE BIT(0) /* CTS Enable */ /* CCR2 (Common Control Register 2) */ #define CCR2_INIT 0xFF000004 #define CCR2_CKS_TCLK (0) /* TCLK clock */ #define CCR2_CKS_TCLK_DIV4 BIT(20) /* TCLK/4 clock */ #define CCR2_CKS_TCLK_DIV16 BIT(21) /* TCLK16 clock */ #define CCR2_CKS_TCLK_DIV64 (BIT(21) | BIT(20)) /* TCLK/64 clock */ #define CCR2_BRME BIT(16) /* Bitrate Modulation Enable */ #define CCR2_ABCSE BIT(6) /* Asynchronous Mode Extended Base Clock Select */ #define CCR2_ABCS BIT(5) /* Asynchronous Mode Base Clock Select */ #define CCR2_BGDM BIT(4) /* Baud Rate Generator Double-Speed Mode Select */ /* CCR3 (Common Control Register 3) */ #define CCR3_INIT 0x1203 #define CCR3_BLK BIT(29) /* Block Transfer Mode */ #define CCR3_GM BIT(28) /* GSM Mode */ #define CCR3_CKE1 BIT(25) /* Clock Enable 1 */ #define CCR3_CKE0 BIT(24) /* Clock Enable 0 */ #define CCR3_DEN BIT(21) /* Driver Enabled */ #define CCR3_FM BIT(20) /* FIFO Mode Select */ #define CCR3_MP BIT(19) /* Multi-Processor Mode */ #define CCR3_MOD_ASYNC 0 /* Asynchronous mode (Multi-processor mode) */ #define CCR3_MOD_IRDA BIT(16) /* Smart card interface mode */ #define CCR3_MOD_CLK_SYNC BIT(17) /* Clock synchronous mode */ #define CCR3_MOD_SPI (BIT(17) | BIT(16)) /* Simple SPI mode */ #define CCR3_MOD_I2C BIT(18) /* Simple I2C mode */ #define CCR3_RXDESEL BIT(15) /* Asynchronous Start Bit Edge Detection Select */ #define CCR3_STP BIT(14) /* Stop bit Length */ #define CCR3_SINV BIT(13) /* Transmitted/Received Data Invert */ #define CCR3_LSBF BIT(12) /* LSB First select */ #define CCR3_CHR1 BIT(9) /* Character Length */ #define CCR3_CHR0 BIT(8) /* Character Length */ #define CCR3_BPEN BIT(7) /* Synchronizer Bypass Enable */ #define CCR3_CPOL BIT(1) /* Clock Polarity Select */ #define CCR3_CPHA BIT(0) /* Clock Phase Select */ /* FCR (FIFO Control Register) */ #define FCR_RFRST BIT(23) /* Receive FIFO Data Register Reset */ #define FCR_TFRST BIT(15) /* Transmit FIFO Data Register Reset */ #define FCR_DRES BIT(0) /* Incoming Data Ready Error Select */ #define FCR_RTRG4_0 GENMASK(20, 16) #define FCR_TTRG GENMASK(12, 8) /* CSR (Common Status Register) */ #define CSR_RDRF BIT(31) /* Receive Data Full */ #define CSR_TEND BIT(30) /* Transmit End Flag */ #define CSR_TDRE BIT(29) /* Transmit Data Empty */ #define CSR_FER BIT(28) /* Framing Error */ #define CSR_PER BIT(27) /* Parity Error */ #define CSR_MFF BIT(26) /* Mode Fault Error */ #define CSR_ORER BIT(24) /* Overrun Error */ #define CSR_DFER BIT(18) /* Data Compare Match Framing Error */ #define CSR_DPER BIT(17) /* Data Compare Match Parity Error */ #define CSR_DCMF BIT(16) /* Data Compare Match */ #define CSR_RXDMON BIT(15) /* Serial Input Data Monitor */ #define CSR_ERS BIT(4) /* Error Signal Status */ #define SCxSR_ERRORS(port) (to_sci_port(port)->params->error_mask) #define SCxSR_ERROR_CLEAR(port) (to_sci_port(port)->params->error_clear) #define RSCI_DEFAULT_ERROR_MASK (CSR_PER | CSR_FER) #define RSCI_RDxF_CLEAR (CFCLR_RDRFC) #define RSCI_ERROR_CLEAR (CFCLR_PERC | CFCLR_FERC) #define RSCI_TDxE_CLEAR (CFCLR_TDREC) #define RSCI_BREAK_CLEAR (CFCLR_PERC | CFCLR_FERC | CFCLR_ORERC) /* FRSR (FIFO Receive Status Register) */ #define FRSR_R5_0 GENMASK(13, 8) /* Receive FIFO Data Count */ #define FRSR_DR BIT(0) /* Receive Data Ready */ /* CFCLR (Common Flag CLear Register) */ #define CFCLR_RDRFC BIT(31) /* RDRF Clear */ #define CFCLR_TDREC BIT(29) /* TDRE Clear */ #define CFCLR_FERC BIT(28) /* FER Clear */ #define CFCLR_PERC BIT(27) /* PER Clear */ #define CFCLR_MFFC BIT(26) /* MFF Clear */ #define CFCLR_ORERC BIT(24) /* ORER Clear */ #define CFCLR_DFERC BIT(18) /* DFER Clear */ #define CFCLR_DPERC BIT(17) /* DPER Clear */ #define CFCLR_DCMFC BIT(16) /* DCMF Clear */ #define CFCLR_ERSC BIT(4) /* ERS Clear */ #define CFCLR_CLRFLAG (CFCLR_RDRFC | CFCLR_FERC | CFCLR_PERC | \ CFCLR_MFFC | CFCLR_ORERC | CFCLR_DFERC | \ CFCLR_DPERC | CFCLR_DCMFC | CFCLR_ERSC) /* FFCLR (FIFO Flag CLear Register) */ #define FFCLR_DRC BIT(0) /* DR Clear */ static u32 rsci_serial_in(struct uart_port *p, int offset) { return readl(p->membase + offset); } static void rsci_serial_out(struct uart_port *p, int offset, int value) { writel(value, p->membase + offset); } static void rsci_clear_DRxC(struct uart_port *port) { rsci_serial_out(port, CFCLR, CFCLR_RDRFC); rsci_serial_out(port, FFCLR, FFCLR_DRC); } static void rsci_start_rx(struct uart_port *port) { unsigned int ctrl; ctrl = rsci_serial_in(port, CCR0); ctrl |= CCR0_RIE; rsci_serial_out(port, CCR0, ctrl); } static void rsci_enable_ms(struct uart_port *port) { mctrl_gpio_enable_ms(to_sci_port(port)->gpios); } static void rsci_init_pins(struct uart_port *port, unsigned int cflag) { struct sci_port *s = to_sci_port(port); /* Use port-specific handler if provided */ if (s->cfg->ops && s->cfg->ops->init_pins) { s->cfg->ops->init_pins(port, cflag); return; } if (!s->has_rtscts) return; if (s->autorts) rsci_serial_out(port, CCR1, rsci_serial_in(port, CCR1) | CCR1_CTSE | CCR1_CTSPEN); } static int rsci_scif_set_rtrg(struct uart_port *port, int rx_trig) { u32 fcr = rsci_serial_in(port, FCR); if (rx_trig >= port->fifosize) rx_trig = port->fifosize - 1; else if (rx_trig < 1) rx_trig = 0; FIELD_MODIFY(FCR_RTRG4_0, &fcr, rx_trig); rsci_serial_out(port, FCR, fcr); return rx_trig; } static void rsci_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { unsigned int ccr2_val = CCR2_INIT, ccr3_val = CCR3_INIT; unsigned int ccr0_val = 0, ccr1_val = 0, ccr4_val = 0; unsigned int brr1 = 255, cks1 = 0, srr1 = 15; struct sci_port *s = to_sci_port(port); unsigned int brr = 255, cks = 0; int min_err = INT_MAX, err; unsigned long max_freq = 0; unsigned int baud, i; unsigned long flags; unsigned int ctrl; int best_clk = -1; if ((termios->c_cflag & CSIZE) == CS7) { ccr3_val |= CCR3_CHR0; } else { termios->c_cflag &= ~CSIZE; termios->c_cflag |= CS8; } if (termios->c_cflag & PARENB) ccr1_val |= CCR1_PE; if (termios->c_cflag & PARODD) ccr1_val |= (CCR1_PE | CCR1_PM); if (termios->c_cflag & CSTOPB) ccr3_val |= CCR3_STP; /* Enable noise filter function */ ccr1_val |= CCR1_NFEN; /* * earlyprintk comes here early on with port->uartclk set to zero. * the clock framework is not up and running at this point so here * we assume that 115200 is the maximum baud rate. please note that * the baud rate is not programmed during earlyprintk - it is assumed * that the previous boot loader has enabled required clocks and * setup the baud rate generator hardware for us already. */ if (!port->uartclk) { max_freq = 115200; } else { for (i = 0; i < SCI_NUM_CLKS; i++) max_freq = max(max_freq, s->clk_rates[i]); max_freq /= min_sr(s); } baud = uart_get_baud_rate(port, termios, old, 0, max_freq); if (!baud) goto done; /* Divided Functional Clock using standard Bit Rate Register */ err = sci_scbrr_calc(s, baud, &brr1, &srr1, &cks1); if (abs(err) < abs(min_err)) { best_clk = SCI_FCK; ccr0_val = 0; min_err = err; brr = brr1; cks = cks1; } done: if (best_clk >= 0) dev_dbg(port->dev, "Using clk %pC for %u%+d bps\n", s->clks[best_clk], baud, min_err); sci_port_enable(s); uart_port_lock_irqsave(port, &flags); uart_update_timeout(port, termios->c_cflag, baud); rsci_serial_out(port, CCR0, ccr0_val); ccr3_val |= CCR3_FM; rsci_serial_out(port, CCR3, ccr3_val); ccr2_val |= (cks << 20) | (brr << 8); rsci_serial_out(port, CCR2, ccr2_val); rsci_serial_out(port, CCR1, ccr1_val); rsci_serial_out(port, CCR4, ccr4_val); ctrl = rsci_serial_in(port, FCR); ctrl |= (FCR_RFRST | FCR_TFRST); rsci_serial_out(port, FCR, ctrl); if (s->rx_trigger > 1) rsci_scif_set_rtrg(port, s->rx_trigger); port->status &= ~UPSTAT_AUTOCTS; s->autorts = false; if ((port->flags & UPF_HARD_FLOW) && (termios->c_cflag & CRTSCTS)) { port->status |= UPSTAT_AUTOCTS; s->autorts = true; } rsci_init_pins(port, termios->c_cflag); rsci_serial_out(port, CFCLR, CFCLR_CLRFLAG); rsci_serial_out(port, FFCLR, FFCLR_DRC); ccr0_val |= CCR0_RE; rsci_serial_out(port, CCR0, ccr0_val); if ((termios->c_cflag & CREAD) != 0) rsci_start_rx(port); uart_port_unlock_irqrestore(port, flags); sci_port_disable(s); if (UART_ENABLE_MS(port, termios->c_cflag)) rsci_enable_ms(port); } static int rsci_txfill(struct uart_port *port) { return rsci_serial_in(port, FTSR); } static int rsci_rxfill(struct uart_port *port) { u32 val = rsci_serial_in(port, FRSR); return FIELD_GET(FRSR_R5_0, val); } static unsigned int rsci_tx_empty(struct uart_port *port) { unsigned int status = rsci_serial_in(port, CSR); unsigned int in_tx_fifo = rsci_txfill(port); return (status & CSR_TEND) && !in_tx_fifo ? TIOCSER_TEMT : 0; } static void rsci_set_mctrl(struct uart_port *port, unsigned int mctrl) { if (mctrl & TIOCM_LOOP) { /* Standard loopback mode */ rsci_serial_out(port, CCR1, rsci_serial_in(port, CCR1) | CCR1_SPLP); } } static unsigned int rsci_get_mctrl(struct uart_port *port) { struct sci_port *s = to_sci_port(port); struct mctrl_gpios *gpios = s->gpios; unsigned int mctrl = 0; mctrl_gpio_get(gpios, &mctrl); /* * CTS/RTS is handled in hardware when supported, while nothing * else is wired up. */ if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_CTS)) mctrl |= TIOCM_CTS; if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DSR)) mctrl |= TIOCM_DSR; if (!mctrl_gpio_to_gpiod(gpios, UART_GPIO_DCD)) mctrl |= TIOCM_CAR; return mctrl; } static void rsci_clear_CFC(struct uart_port *port, unsigned int mask) { rsci_serial_out(port, CFCLR, mask); } static void rsci_start_tx(struct uart_port *port) { struct sci_port *sp = to_sci_port(port); u32 ctrl; if (sp->chan_tx) return; /* * TE (Transmit Enable) must be set after setting TIE * (Transmit Interrupt Enable) or in the same instruction * to start the transmit process. */ ctrl = rsci_serial_in(port, CCR0); ctrl |= CCR0_TIE | CCR0_TE; rsci_serial_out(port, CCR0, ctrl); } static void rsci_stop_tx(struct uart_port *port) { u32 ctrl; ctrl = rsci_serial_in(port, CCR0); ctrl &= ~CCR0_TIE; rsci_serial_out(port, CCR0, ctrl); } static void rsci_stop_rx(struct uart_port *port) { u32 ctrl; ctrl = rsci_serial_in(port, CCR0); ctrl &= ~CCR0_RIE; rsci_serial_out(port, CCR0, ctrl); } static int rsci_txroom(struct uart_port *port) { return port->fifosize - rsci_txfill(port); } static void rsci_transmit_chars(struct uart_port *port) { unsigned int stopped = uart_tx_stopped(port); struct tty_port *tport = &port->state->port; u32 status, ctrl; int count; status = rsci_serial_in(port, CSR); if (!(status & CSR_TDRE)) { ctrl = rsci_serial_in(port, CCR0); if (kfifo_is_empty(&tport->xmit_fifo)) ctrl &= ~CCR0_TIE; else ctrl |= CCR0_TIE; rsci_serial_out(port, CCR0, ctrl); return; } count = rsci_txroom(port); do { unsigned char c; if (port->x_char) { c = port->x_char; port->x_char = 0; } else if (stopped || !kfifo_get(&tport->xmit_fifo, &c)) { break; } rsci_clear_CFC(port, CFCLR_TDREC); rsci_serial_out(port, TDR, c); port->icount.tx++; } while (--count > 0); if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) uart_write_wakeup(port); if (kfifo_is_empty(&tport->xmit_fifo)) { ctrl = rsci_serial_in(port, CCR0); ctrl &= ~CCR0_TIE; ctrl |= CCR0_TEIE; rsci_serial_out(port, CCR0, ctrl); } } static void rsci_receive_chars(struct uart_port *port) { struct tty_port *tport = &port->state->port; u32 rdat, status, frsr_status = 0; int i, count, copied = 0; unsigned char flag; status = rsci_serial_in(port, CSR); frsr_status = rsci_serial_in(port, FRSR); if (!(status & CSR_RDRF) && !(frsr_status & FRSR_DR)) return; while (1) { /* Don't copy more bytes than there is room for in the buffer */ count = tty_buffer_request_room(tport, rsci_rxfill(port)); /* If for any reason we can't copy more data, we're done! */ if (count == 0) break; for (i = 0; i < count; i++) { char c; rdat = rsci_serial_in(port, RDR); /* 9-bits data is not supported yet */ c = rdat & RDR_RDAT_MSK; if (uart_handle_sysrq_char(port, c)) { count--; i--; continue; } /* * Store data and status. * Non FIFO mode is not supported */ if (rdat & RDR_FFER) { flag = TTY_FRAME; port->icount.frame++; } else if (rdat & RDR_FPER) { flag = TTY_PARITY; port->icount.parity++; } else { flag = TTY_NORMAL; } tty_insert_flip_char(tport, c, flag); } rsci_serial_in(port, CSR); /* dummy read */ rsci_clear_DRxC(port); copied += count; port->icount.rx += count; } if (copied) { /* Tell the rest of the system the news. New characters! */ tty_flip_buffer_push(tport); } else { /* TTY buffers full; read from RX reg to prevent lockup */ rsci_serial_in(port, RDR); rsci_serial_in(port, CSR); /* dummy read */ rsci_clear_DRxC(port); } } static void rsci_break_ctl(struct uart_port *port, int break_state) { unsigned short ccr0_val, ccr1_val; unsigned long flags; uart_port_lock_irqsave(port, &flags); ccr1_val = rsci_serial_in(port, CCR1); ccr0_val = rsci_serial_in(port, CCR0); if (break_state == -1) { ccr1_val = (ccr1_val | CCR1_SPB2IO) & ~CCR1_SPB2DT; ccr0_val &= ~CCR0_TE; } else { ccr1_val = (ccr1_val | CCR1_SPB2DT) & ~CCR1_SPB2IO; ccr0_val |= CCR0_TE; } rsci_serial_out(port, CCR1, ccr1_val); rsci_serial_out(port, CCR0, ccr0_val); uart_port_unlock_irqrestore(port, flags); } static void rsci_poll_put_char(struct uart_port *port, unsigned char c) { u32 status; int ret; ret = readl_relaxed_poll_timeout_atomic(port->membase + CSR, status, (status & CSR_TDRE), 100, USEC_PER_SEC); if (ret != 0) { dev_err(port->dev, "Error while sending data in UART TX : %d\n", ret); goto done; } rsci_serial_out(port, TDR, c); done: rsci_clear_CFC(port, CFCLR_TDREC); } static void rsci_prepare_console_write(struct uart_port *port, u32 ctrl) { struct sci_port *s = to_sci_port(port); u32 ctrl_temp = s->params->param_bits->rxtx_enable; if (s->type == RSCI_PORT_SCIF16) ctrl_temp |= CCR0_TIE | s->hscif_tot; rsci_serial_out(port, CCR0, ctrl_temp); } static void rsci_finish_console_write(struct uart_port *port, u32 ctrl) { /* First set TE = 0 and then restore the CCR0 value */ rsci_serial_out(port, CCR0, ctrl & ~CCR0_TE); rsci_serial_out(port, CCR0, ctrl); } static const char *rsci_type(struct uart_port *port) { return "rsci"; } static size_t rsci_suspend_regs_size(void) { return 0; } static void rsci_shutdown_complete(struct uart_port *port) { /* * Stop RX and TX, disable related interrupts, keep clock source */ rsci_serial_out(port, CCR0, 0); } static const struct sci_common_regs rsci_common_regs = { .status = CSR, .control = CCR0, }; static const struct sci_port_params_bits rsci_port_param_bits = { .rxtx_enable = CCR0_RE | CCR0_TE, .te_clear = CCR0_TE | CCR0_TEIE, .poll_sent_bits = CSR_TDRE | CSR_TEND, }; static const struct sci_port_params rsci_rzg3e_port_params = { .fifosize = 32, .overrun_reg = CSR, .overrun_mask = CSR_ORER, .sampling_rate_mask = SCI_SR(32), .error_mask = RSCI_DEFAULT_ERROR_MASK, .error_clear = RSCI_ERROR_CLEAR, .param_bits = &rsci_port_param_bits, .common_regs = &rsci_common_regs, }; static const struct sci_port_params rsci_rzt2h_port_params = { .fifosize = 16, .overrun_reg = CSR, .overrun_mask = CSR_ORER, .sampling_rate_mask = SCI_SR(32), .error_mask = RSCI_DEFAULT_ERROR_MASK, .error_clear = RSCI_ERROR_CLEAR, .param_bits = &rsci_port_param_bits, .common_regs = &rsci_common_regs, }; static const struct uart_ops rsci_uart_ops = { .tx_empty = rsci_tx_empty, .set_mctrl = rsci_set_mctrl, .get_mctrl = rsci_get_mctrl, .start_tx = rsci_start_tx, .stop_tx = rsci_stop_tx, .stop_rx = rsci_stop_rx, .enable_ms = rsci_enable_ms, .break_ctl = rsci_break_ctl, .startup = sci_startup, .shutdown = sci_shutdown, .set_termios = rsci_set_termios, .pm = sci_pm, .type = rsci_type, .release_port = sci_release_port, .request_port = sci_request_port, .config_port = sci_config_port, .verify_port = sci_verify_port, }; static const struct sci_port_ops rsci_port_ops = { .read_reg = rsci_serial_in, .write_reg = rsci_serial_out, .clear_SCxSR = rsci_clear_CFC, .transmit_chars = rsci_transmit_chars, .receive_chars = rsci_receive_chars, .poll_put_char = rsci_poll_put_char, .prepare_console_write = rsci_prepare_console_write, .finish_console_write = rsci_finish_console_write, .suspend_regs_size = rsci_suspend_regs_size, .set_rtrg = rsci_scif_set_rtrg, .shutdown_complete = rsci_shutdown_complete, }; struct sci_of_data of_rsci_rzg3e_data = { .type = RSCI_PORT_SCIF32, .ops = &rsci_port_ops, .uart_ops = &rsci_uart_ops, .params = &rsci_rzg3e_port_params, }; struct sci_of_data of_rsci_rzt2h_data = { .type = RSCI_PORT_SCIF16, .ops = &rsci_port_ops, .uart_ops = &rsci_uart_ops, .params = &rsci_rzt2h_port_params, }; #ifdef CONFIG_SERIAL_SH_SCI_EARLYCON static int __init rsci_rzg3e_early_console_setup(struct earlycon_device *device, const char *opt) { return scix_early_console_setup(device, &of_rsci_rzg3e_data); } static int __init rsci_rzt2h_early_console_setup(struct earlycon_device *device, const char *opt) { return scix_early_console_setup(device, &of_rsci_rzt2h_data); } OF_EARLYCON_DECLARE(rsci, "renesas,r9a09g047-rsci", rsci_rzg3e_early_console_setup); OF_EARLYCON_DECLARE(rsci, "renesas,r9a09g077-rsci", rsci_rzt2h_early_console_setup); #endif /* CONFIG_SERIAL_SH_SCI_EARLYCON */ MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("RSCI serial driver");