/* * Actions Semi Owl family serial console * * Copyright 2013 Actions Semi Inc. * Author: Actions Semi, Inc. * * Copyright (c) 2016-2017 Andreas Färber * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include #include #include #include #include #include #include #include #include #include #include #define OWL_UART_PORT_NUM 7 #define OWL_UART_DEV_NAME "ttyOWL" #define OWL_UART_CTL 0x000 #define OWL_UART_RXDAT 0x004 #define OWL_UART_TXDAT 0x008 #define OWL_UART_STAT 0x00c #define OWL_UART_CTL_DWLS_MASK GENMASK(1, 0) #define OWL_UART_CTL_DWLS_5BITS (0x0 << 0) #define OWL_UART_CTL_DWLS_6BITS (0x1 << 0) #define OWL_UART_CTL_DWLS_7BITS (0x2 << 0) #define OWL_UART_CTL_DWLS_8BITS (0x3 << 0) #define OWL_UART_CTL_STPS_2BITS BIT(2) #define OWL_UART_CTL_PRS_MASK GENMASK(6, 4) #define OWL_UART_CTL_PRS_NONE (0x0 << 4) #define OWL_UART_CTL_PRS_ODD (0x4 << 4) #define OWL_UART_CTL_PRS_MARK (0x5 << 4) #define OWL_UART_CTL_PRS_EVEN (0x6 << 4) #define OWL_UART_CTL_PRS_SPACE (0x7 << 4) #define OWL_UART_CTL_AFE BIT(12) #define OWL_UART_CTL_TRFS_TX BIT(14) #define OWL_UART_CTL_EN BIT(15) #define OWL_UART_CTL_RXDE BIT(16) #define OWL_UART_CTL_TXDE BIT(17) #define OWL_UART_CTL_RXIE BIT(18) #define OWL_UART_CTL_TXIE BIT(19) #define OWL_UART_CTL_LBEN BIT(20) #define OWL_UART_STAT_RIP BIT(0) #define OWL_UART_STAT_TIP BIT(1) #define OWL_UART_STAT_RXER BIT(2) #define OWL_UART_STAT_TFER BIT(3) #define OWL_UART_STAT_RXST BIT(4) #define OWL_UART_STAT_RFEM BIT(5) #define OWL_UART_STAT_TFFU BIT(6) #define OWL_UART_STAT_CTSS BIT(7) #define OWL_UART_STAT_RTSS BIT(8) #define OWL_UART_STAT_TFES BIT(10) #define OWL_UART_STAT_TRFL_MASK GENMASK(16, 11) #define OWL_UART_STAT_UTBB BIT(17) static struct uart_driver owl_uart_driver; struct owl_uart_info { unsigned int tx_fifosize; }; struct owl_uart_port { struct uart_port port; struct clk *clk; }; #define to_owl_uart_port(prt) container_of(prt, struct owl_uart_port, prt) static struct owl_uart_port *owl_uart_ports[OWL_UART_PORT_NUM]; static inline void owl_uart_write(struct uart_port *port, u32 val, unsigned int off) { writel(val, port->membase + off); } static inline u32 owl_uart_read(struct uart_port *port, unsigned int off) { return readl(port->membase + off); } static void owl_uart_set_mctrl(struct uart_port *port, unsigned int mctrl) { u32 ctl; ctl = owl_uart_read(port, OWL_UART_CTL); if (mctrl & TIOCM_LOOP) ctl |= OWL_UART_CTL_LBEN; else ctl &= ~OWL_UART_CTL_LBEN; owl_uart_write(port, ctl, OWL_UART_CTL); } static unsigned int owl_uart_get_mctrl(struct uart_port *port) { unsigned int mctrl = TIOCM_CAR | TIOCM_DSR; u32 stat, ctl; ctl = owl_uart_read(port, OWL_UART_CTL); stat = owl_uart_read(port, OWL_UART_STAT); if (stat & OWL_UART_STAT_RTSS) mctrl |= TIOCM_RTS; if ((stat & OWL_UART_STAT_CTSS) || !(ctl & OWL_UART_CTL_AFE)) mctrl |= TIOCM_CTS; return mctrl; } static unsigned int owl_uart_tx_empty(struct uart_port *port) { unsigned long flags; u32 val; unsigned int ret; spin_lock_irqsave(&port->lock, flags); val = owl_uart_read(port, OWL_UART_STAT); ret = (val & OWL_UART_STAT_TFES) ? TIOCSER_TEMT : 0; spin_unlock_irqrestore(&port->lock, flags); return ret; } static void owl_uart_stop_rx(struct uart_port *port) { u32 val; val = owl_uart_read(port, OWL_UART_CTL); val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_RXDE); owl_uart_write(port, val, OWL_UART_CTL); val = owl_uart_read(port, OWL_UART_STAT); val |= OWL_UART_STAT_RIP; owl_uart_write(port, val, OWL_UART_STAT); } static void owl_uart_stop_tx(struct uart_port *port) { u32 val; val = owl_uart_read(port, OWL_UART_CTL); val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_TXDE); owl_uart_write(port, val, OWL_UART_CTL); val = owl_uart_read(port, OWL_UART_STAT); val |= OWL_UART_STAT_TIP; owl_uart_write(port, val, OWL_UART_STAT); } static void owl_uart_start_tx(struct uart_port *port) { u32 val; if (uart_tx_stopped(port)) { owl_uart_stop_tx(port); return; } val = owl_uart_read(port, OWL_UART_STAT); val |= OWL_UART_STAT_TIP; owl_uart_write(port, val, OWL_UART_STAT); val = owl_uart_read(port, OWL_UART_CTL); val |= OWL_UART_CTL_TXIE; owl_uart_write(port, val, OWL_UART_CTL); } static void owl_uart_send_chars(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; unsigned int ch; if (uart_tx_stopped(port)) return; if (port->x_char) { while (!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)) cpu_relax(); owl_uart_write(port, port->x_char, OWL_UART_TXDAT); port->icount.tx++; port->x_char = 0; } while (!(owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU)) { if (uart_circ_empty(xmit)) break; ch = xmit->buf[xmit->tail]; owl_uart_write(port, ch, OWL_UART_TXDAT); xmit->tail = (xmit->tail + 1) & (SERIAL_XMIT_SIZE - 1); port->icount.tx++; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); if (uart_circ_empty(xmit)) owl_uart_stop_tx(port); } static void owl_uart_receive_chars(struct uart_port *port) { u32 stat, val; val = owl_uart_read(port, OWL_UART_CTL); val &= ~OWL_UART_CTL_TRFS_TX; owl_uart_write(port, val, OWL_UART_CTL); stat = owl_uart_read(port, OWL_UART_STAT); while (!(stat & OWL_UART_STAT_RFEM)) { char flag = TTY_NORMAL; if (stat & OWL_UART_STAT_RXER) port->icount.overrun++; if (stat & OWL_UART_STAT_RXST) { /* We are not able to distinguish the error type. */ port->icount.brk++; port->icount.frame++; stat &= port->read_status_mask; if (stat & OWL_UART_STAT_RXST) flag = TTY_PARITY; } else port->icount.rx++; val = owl_uart_read(port, OWL_UART_RXDAT); val &= 0xff; if ((stat & port->ignore_status_mask) == 0) tty_insert_flip_char(&port->state->port, val, flag); stat = owl_uart_read(port, OWL_UART_STAT); } spin_unlock(&port->lock); tty_flip_buffer_push(&port->state->port); spin_lock(&port->lock); } static irqreturn_t owl_uart_irq(int irq, void *dev_id) { struct uart_port *port = dev_id; unsigned long flags; u32 stat; spin_lock_irqsave(&port->lock, flags); stat = owl_uart_read(port, OWL_UART_STAT); if (stat & OWL_UART_STAT_RIP) owl_uart_receive_chars(port); if (stat & OWL_UART_STAT_TIP) owl_uart_send_chars(port); stat = owl_uart_read(port, OWL_UART_STAT); stat |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP; owl_uart_write(port, stat, OWL_UART_STAT); spin_unlock_irqrestore(&port->lock, flags); return IRQ_HANDLED; } static void owl_uart_shutdown(struct uart_port *port) { u32 val; unsigned long flags; spin_lock_irqsave(&port->lock, flags); val = owl_uart_read(port, OWL_UART_CTL); val &= ~(OWL_UART_CTL_TXIE | OWL_UART_CTL_RXIE | OWL_UART_CTL_TXDE | OWL_UART_CTL_RXDE | OWL_UART_CTL_EN); owl_uart_write(port, val, OWL_UART_CTL); spin_unlock_irqrestore(&port->lock, flags); free_irq(port->irq, port); } static int owl_uart_startup(struct uart_port *port) { u32 val; unsigned long flags; int ret; ret = request_irq(port->irq, owl_uart_irq, IRQF_TRIGGER_HIGH, "owl-uart", port); if (ret) return ret; spin_lock_irqsave(&port->lock, flags); val = owl_uart_read(port, OWL_UART_STAT); val |= OWL_UART_STAT_RIP | OWL_UART_STAT_TIP | OWL_UART_STAT_RXER | OWL_UART_STAT_TFER | OWL_UART_STAT_RXST; owl_uart_write(port, val, OWL_UART_STAT); val = owl_uart_read(port, OWL_UART_CTL); val |= OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE; val |= OWL_UART_CTL_EN; owl_uart_write(port, val, OWL_UART_CTL); spin_unlock_irqrestore(&port->lock, flags); return 0; } static void owl_uart_change_baudrate(struct owl_uart_port *owl_port, unsigned long baud) { clk_set_rate(owl_port->clk, baud * 8); } static void owl_uart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) { struct owl_uart_port *owl_port = to_owl_uart_port(port); unsigned int baud; u32 ctl; unsigned long flags; spin_lock_irqsave(&port->lock, flags); ctl = owl_uart_read(port, OWL_UART_CTL); ctl &= ~OWL_UART_CTL_DWLS_MASK; switch (termios->c_cflag & CSIZE) { case CS5: ctl |= OWL_UART_CTL_DWLS_5BITS; break; case CS6: ctl |= OWL_UART_CTL_DWLS_6BITS; break; case CS7: ctl |= OWL_UART_CTL_DWLS_7BITS; break; case CS8: default: ctl |= OWL_UART_CTL_DWLS_8BITS; break; } if (termios->c_cflag & CSTOPB) ctl |= OWL_UART_CTL_STPS_2BITS; else ctl &= ~OWL_UART_CTL_STPS_2BITS; ctl &= ~OWL_UART_CTL_PRS_MASK; if (termios->c_cflag & PARENB) { if (termios->c_cflag & CMSPAR) { if (termios->c_cflag & PARODD) ctl |= OWL_UART_CTL_PRS_MARK; else ctl |= OWL_UART_CTL_PRS_SPACE; } else if (termios->c_cflag & PARODD) ctl |= OWL_UART_CTL_PRS_ODD; else ctl |= OWL_UART_CTL_PRS_EVEN; } else ctl |= OWL_UART_CTL_PRS_NONE; if (termios->c_cflag & CRTSCTS) ctl |= OWL_UART_CTL_AFE; else ctl &= ~OWL_UART_CTL_AFE; owl_uart_write(port, ctl, OWL_UART_CTL); baud = uart_get_baud_rate(port, termios, old, 9600, 3200000); owl_uart_change_baudrate(owl_port, baud); /* Don't rewrite B0 */ if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); port->read_status_mask |= OWL_UART_STAT_RXER; if (termios->c_iflag & INPCK) port->read_status_mask |= OWL_UART_STAT_RXST; uart_update_timeout(port, termios->c_cflag, baud); spin_unlock_irqrestore(&port->lock, flags); } static void owl_uart_release_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *res; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) return; if (port->flags & UPF_IOREMAP) { devm_release_mem_region(port->dev, port->mapbase, resource_size(res)); devm_iounmap(port->dev, port->membase); port->membase = NULL; } } static int owl_uart_request_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *res; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) return -ENXIO; if (!devm_request_mem_region(port->dev, port->mapbase, resource_size(res), dev_name(port->dev))) return -EBUSY; if (port->flags & UPF_IOREMAP) { port->membase = devm_ioremap_nocache(port->dev, port->mapbase, resource_size(res)); if (!port->membase) return -EBUSY; } return 0; } static const char *owl_uart_type(struct uart_port *port) { return (port->type == PORT_OWL) ? "owl-uart" : NULL; } static int owl_uart_verify_port(struct uart_port *port, struct serial_struct *ser) { if (port->type != PORT_OWL) return -EINVAL; if (port->irq != ser->irq) return -EINVAL; return 0; } static void owl_uart_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { port->type = PORT_OWL; owl_uart_request_port(port); } } static const struct uart_ops owl_uart_ops = { .set_mctrl = owl_uart_set_mctrl, .get_mctrl = owl_uart_get_mctrl, .tx_empty = owl_uart_tx_empty, .start_tx = owl_uart_start_tx, .stop_rx = owl_uart_stop_rx, .stop_tx = owl_uart_stop_tx, .startup = owl_uart_startup, .shutdown = owl_uart_shutdown, .set_termios = owl_uart_set_termios, .type = owl_uart_type, .config_port = owl_uart_config_port, .request_port = owl_uart_request_port, .release_port = owl_uart_release_port, .verify_port = owl_uart_verify_port, }; #ifdef CONFIG_SERIAL_OWL_CONSOLE static void owl_console_putchar(struct uart_port *port, int ch) { if (!port->membase) return; while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU) cpu_relax(); owl_uart_write(port, ch, OWL_UART_TXDAT); } static void owl_uart_port_write(struct uart_port *port, const char *s, u_int count) { u32 old_ctl, val; unsigned long flags; int locked; local_irq_save(flags); if (port->sysrq) locked = 0; else if (oops_in_progress) locked = spin_trylock(&port->lock); else { spin_lock(&port->lock); locked = 1; } old_ctl = owl_uart_read(port, OWL_UART_CTL); val = old_ctl | OWL_UART_CTL_TRFS_TX; /* disable IRQ */ val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE); owl_uart_write(port, val, OWL_UART_CTL); uart_console_write(port, s, count, owl_console_putchar); /* wait until all contents have been sent out */ while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TRFL_MASK) cpu_relax(); /* clear IRQ pending */ val = owl_uart_read(port, OWL_UART_STAT); val |= OWL_UART_STAT_TIP | OWL_UART_STAT_RIP; owl_uart_write(port, val, OWL_UART_STAT); owl_uart_write(port, old_ctl, OWL_UART_CTL); if (locked) spin_unlock(&port->lock); local_irq_restore(flags); } static void owl_uart_console_write(struct console *co, const char *s, u_int count) { struct owl_uart_port *owl_port; owl_port = owl_uart_ports[co->index]; if (!owl_port) return; owl_uart_port_write(&owl_port->port, s, count); } static int owl_uart_console_setup(struct console *co, char *options) { struct owl_uart_port *owl_port; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; if (co->index < 0 || co->index >= OWL_UART_PORT_NUM) return -EINVAL; owl_port = owl_uart_ports[co->index]; if (!owl_port || !owl_port->port.membase) return -ENODEV; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); return uart_set_options(&owl_port->port, co, baud, parity, bits, flow); } static struct console owl_uart_console = { .name = OWL_UART_DEV_NAME, .write = owl_uart_console_write, .device = uart_console_device, .setup = owl_uart_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &owl_uart_driver, }; static int __init owl_uart_console_init(void) { register_console(&owl_uart_console); return 0; } console_initcall(owl_uart_console_init); static void owl_uart_early_console_write(struct console *co, const char *s, u_int count) { struct earlycon_device *dev = co->data; owl_uart_port_write(&dev->port, s, count); } static int __init owl_uart_early_console_setup(struct earlycon_device *device, const char *opt) { if (!device->port.membase) return -ENODEV; device->con->write = owl_uart_early_console_write; return 0; } OF_EARLYCON_DECLARE(owl, "actions,owl-uart", owl_uart_early_console_setup); #define OWL_UART_CONSOLE (&owl_uart_console) #else #define OWL_UART_CONSOLE NULL #endif static struct uart_driver owl_uart_driver = { .owner = THIS_MODULE, .driver_name = "owl-uart", .dev_name = OWL_UART_DEV_NAME, .nr = OWL_UART_PORT_NUM, .cons = OWL_UART_CONSOLE, }; static const struct owl_uart_info owl_s500_info = { .tx_fifosize = 16, }; static const struct owl_uart_info owl_s900_info = { .tx_fifosize = 32, }; static const struct of_device_id owl_uart_dt_matches[] = { { .compatible = "actions,s500-uart", .data = &owl_s500_info }, { .compatible = "actions,s900-uart", .data = &owl_s900_info }, { } }; MODULE_DEVICE_TABLE(of, owl_uart_dt_matches); static int owl_uart_probe(struct platform_device *pdev) { const struct of_device_id *match; const struct owl_uart_info *info = NULL; struct resource *res_mem; struct owl_uart_port *owl_port; int ret, irq; if (pdev->dev.of_node) { pdev->id = of_alias_get_id(pdev->dev.of_node, "serial"); match = of_match_node(owl_uart_dt_matches, pdev->dev.of_node); if (match) info = match->data; } if (pdev->id < 0 || pdev->id >= OWL_UART_PORT_NUM) { dev_err(&pdev->dev, "id %d out of range\n", pdev->id); return -EINVAL; } res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res_mem) { dev_err(&pdev->dev, "could not get mem\n"); return -ENODEV; } irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(&pdev->dev, "could not get irq\n"); return irq; } if (owl_uart_ports[pdev->id]) { dev_err(&pdev->dev, "port %d already allocated\n", pdev->id); return -EBUSY; } owl_port = devm_kzalloc(&pdev->dev, sizeof(*owl_port), GFP_KERNEL); if (!owl_port) return -ENOMEM; owl_port->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(owl_port->clk)) { dev_err(&pdev->dev, "could not get clk\n"); return PTR_ERR(owl_port->clk); } owl_port->port.dev = &pdev->dev; owl_port->port.line = pdev->id; owl_port->port.type = PORT_OWL; owl_port->port.iotype = UPIO_MEM; owl_port->port.mapbase = res_mem->start; owl_port->port.irq = irq; owl_port->port.uartclk = clk_get_rate(owl_port->clk); if (owl_port->port.uartclk == 0) { dev_err(&pdev->dev, "clock rate is zero\n"); return -EINVAL; } owl_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY; owl_port->port.x_char = 0; owl_port->port.fifosize = (info) ? info->tx_fifosize : 16; owl_port->port.ops = &owl_uart_ops; owl_uart_ports[pdev->id] = owl_port; platform_set_drvdata(pdev, owl_port); ret = uart_add_one_port(&owl_uart_driver, &owl_port->port); if (ret) owl_uart_ports[pdev->id] = NULL; return ret; } static int owl_uart_remove(struct platform_device *pdev) { struct owl_uart_port *owl_port = platform_get_drvdata(pdev); uart_remove_one_port(&owl_uart_driver, &owl_port->port); owl_uart_ports[pdev->id] = NULL; return 0; } static struct platform_driver owl_uart_platform_driver = { .probe = owl_uart_probe, .remove = owl_uart_remove, .driver = { .name = "owl-uart", .of_match_table = owl_uart_dt_matches, }, }; static int __init owl_uart_init(void) { int ret; ret = uart_register_driver(&owl_uart_driver); if (ret) return ret; ret = platform_driver_register(&owl_uart_platform_driver); if (ret) uart_unregister_driver(&owl_uart_driver); return ret; } static void __exit owl_uart_exit(void) { platform_driver_unregister(&owl_uart_platform_driver); uart_unregister_driver(&owl_uart_driver); } module_init(owl_uart_init); module_exit(owl_uart_exit); MODULE_LICENSE("GPL");