Implement serial console driver to complement earlycon. Based on LeMaker linux-actions tree. Signed-off-by: Andreas Färber <afaerber@xxxxxxx> --- v2 -> v3: * Adopted BIT() macro * Implemented baudrate setting v2: new drivers/tty/serial/Kconfig | 4 +- drivers/tty/serial/owl-uart.c | 591 ++++++++++++++++++++++++++++++++++++++- include/uapi/linux/serial_core.h | 3 + 3 files changed, 595 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index e145822..ef232ac 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1678,7 +1678,7 @@ config SERIAL_MVEBU_CONSOLE Otherwise, say 'N'. config SERIAL_OWL - bool "Actions Semi Owl serial port support" + tristate "Actions Semi Owl serial port support" depends on ARCH_ACTIONS || COMPILE_TEST select SERIAL_CORE help @@ -1694,7 +1694,7 @@ config SERIAL_OWL_CONSOLE default y help Say 'Y' here if you wish to use Actions Semiconductor S500/S900 UART - as the system console. Only earlycon is implemented currently. + as the system console. endmenu diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c index 1b80087..14e0324 100644 --- a/drivers/tty/serial/owl-uart.c +++ b/drivers/tty/serial/owl-uart.c @@ -20,6 +20,7 @@ * along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <linux/clk.h> #include <linux/console.h> #include <linux/delay.h> #include <linux/io.h> @@ -28,22 +29,59 @@ #include <linux/platform_device.h> #include <linux/serial.h> #include <linux/serial_core.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> + +#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 (0x3 << 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 (0x7 << 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_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_TFES BIT(10) #define OWL_UART_STAT_TRFL_MASK (0x1f << 11) #define OWL_UART_STAT_UTBB BIT(17) +static struct uart_driver owl_uart_driver; + +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); @@ -54,6 +92,380 @@ 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) +{ +} + +static unsigned int owl_uart_get_mctrl(struct uart_port *port) +{ + return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; +} + +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 = (struct uart_port *)dev_id; + u32 stat; + + spin_lock(&port->lock); + + 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(&port->lock); + + 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); + + /* We don't support modem control lines. */ + termios->c_cflag &= ~(HUPCL | CMSPAR); + termios->c_cflag |= CLOCAL; + + /* We don't support BREAK character recognition. */ + termios->c_iflag &= ~(IGNBRK | BRKINT); + + 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); + + 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 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) @@ -110,6 +522,57 @@ static void owl_uart_port_write(struct uart_port *port, const char *s, 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) @@ -132,4 +595,130 @@ owl_uart_early_console_setup(struct earlycon_device *device, const char *opt) OF_EARLYCON_DECLARE(owl, "actions,owl-uart", owl_uart_early_console_setup); -#endif /* CONFIG_SERIAL_OWL_CONSOLE */ +#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 int owl_uart_probe(struct platform_device *pdev) +{ + struct resource *res_mem, *res_irq; + struct owl_uart_port *owl_port; + int ret; + + if (pdev->dev.of_node) + pdev->id = of_alias_get_id(pdev->dev.of_node, "serial"); + + 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; + } + + res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!res_irq) { + dev_err(&pdev->dev, "could not get irq\n"); + return -ENODEV; + } + + 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 = 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 = res_irq->start; + owl_port->port.uartclk = clk_get_rate(owl_port->clk); + owl_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY; + owl_port->port.x_char = 0; + owl_port->port.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; + + 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 const struct of_device_id owl_uart_dt_matches[] = { + { .compatible = "actions,owl-uart" }, + { } +}; +MODULE_DEVICE_TABLE(of, owl_uart_dt_matches); + +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 __init 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"); diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h index 9ec741b..5e850e6 100644 --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -271,4 +271,7 @@ /* MPS2 UART */ #define PORT_MPS2UART 116 +/* Actions Semi Owl UART */ +#define PORT_OWL 117 + #endif /* _UAPILINUX_SERIAL_CORE_H */ -- 2.10.2 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
