diff options
Diffstat (limited to 'drivers/serial/serial_zynq.c')
| -rw-r--r-- | drivers/serial/serial_zynq.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/drivers/serial/serial_zynq.c b/drivers/serial/serial_zynq.c new file mode 100644 index 0000000..3832236 --- /dev/null +++ b/drivers/serial/serial_zynq.c @@ -0,0 +1,247 @@ +/* + * Copyright (C) 2012 Michal Simek <monstr@monstr.eu> + * Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved. + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +#include <common.h> +#include <watchdog.h> +#include <asm/io.h> +#include <linux/compiler.h> +#include <serial.h> + +#define ZYNQ_UART_SR_TXFULL 0x00000010 /* TX FIFO full */ +#define ZYNQ_UART_SR_RXEMPTY 0x00000002 /* RX FIFO empty */ + +#define ZYNQ_UART_CR_TX_EN 0x00000010 /* TX enabled */ +#define ZYNQ_UART_CR_RX_EN 0x00000004 /* RX enabled */ +#define ZYNQ_UART_CR_TXRST 0x00000002 /* TX logic reset */ +#define ZYNQ_UART_CR_RXRST 0x00000001 /* RX logic reset */ + +#define ZYNQ_UART_MR_PARITY_NONE 0x00000020 /* No parity mode */ + +/* Some clock/baud constants */ +#define ZYNQ_UART_BDIV 15 /* Default/reset BDIV value */ +#define ZYNQ_UART_BASECLK 3125000L /* master / (bdiv + 1) */ + +struct uart_zynq { + u32 control; /* Control Register [8:0] */ + u32 mode; /* Mode Register [10:0] */ + u32 reserved1[4]; + u32 baud_rate_gen; /* Baud Rate Generator [15:0] */ + u32 reserved2[4]; + u32 channel_sts; /* Channel Status [11:0] */ + u32 tx_rx_fifo; /* FIFO [15:0] or [7:0] */ + u32 baud_rate_divider; /* Baud Rate Divider [7:0] */ +}; + +static struct uart_zynq *uart_zynq_ports[2] = { +#ifdef CONFIG_ZYNQ_SERIAL_BASEADDR0 + [0] = (struct uart_zynq *)CONFIG_ZYNQ_SERIAL_BASEADDR0, +#endif +#ifdef CONFIG_ZYNQ_SERIAL_BASEADDR1 + [1] = (struct uart_zynq *)CONFIG_ZYNQ_SERIAL_BASEADDR1, +#endif +}; + +struct uart_zynq_params { + u32 baudrate; + u32 clock; +}; + +static struct uart_zynq_params uart_zynq_ports_param[2] = { +#if defined(CONFIG_ZYNQ_SERIAL_BAUDRATE0) && defined(CONFIG_ZYNQ_SERIAL_CLOCK0) + [0].baudrate = CONFIG_ZYNQ_SERIAL_BAUDRATE0, + [0].clock = CONFIG_ZYNQ_SERIAL_CLOCK0, +#endif +#if defined(CONFIG_ZYNQ_SERIAL_BAUDRATE1) && defined(CONFIG_ZYNQ_SERIAL_CLOCK1) + [1].baudrate = CONFIG_ZYNQ_SERIAL_BAUDRATE1, + [1].clock = CONFIG_ZYNQ_SERIAL_CLOCK1, +#endif +}; + +/* Set up the baud rate in gd struct */ +static void uart_zynq_serial_setbrg(const int port) +{ + /* Calculation results. */ + unsigned int calc_bauderror, bdiv, bgen; + unsigned long calc_baud = 0; + unsigned long baud = uart_zynq_ports_param[port].baudrate; + unsigned long clock = uart_zynq_ports_param[port].clock; + struct uart_zynq *regs = uart_zynq_ports[port]; + + /* master clock + * Baud rate = ------------------ + * bgen * (bdiv + 1) + * + * Find acceptable values for baud generation. + */ + for (bdiv = 4; bdiv < 255; bdiv++) { + bgen = clock / (baud * (bdiv + 1)); + if (bgen < 2 || bgen > 65535) + continue; + + calc_baud = clock / (bgen * (bdiv + 1)); + + /* + * Use first calculated baudrate with + * an acceptable (<3%) error + */ + if (baud > calc_baud) + calc_bauderror = baud - calc_baud; + else + calc_bauderror = calc_baud - baud; + if (((calc_bauderror * 100) / baud) < 3) + break; + } + + writel(bdiv, ®s->baud_rate_divider); + writel(bgen, ®s->baud_rate_gen); +} + +/* Initialize the UART, with...some settings. */ +static int uart_zynq_serial_init(const int port) +{ + struct uart_zynq *regs = uart_zynq_ports[port]; + + if (!regs) + return -1; + + /* RX/TX enabled & reset */ + writel(ZYNQ_UART_CR_TX_EN | ZYNQ_UART_CR_RX_EN | ZYNQ_UART_CR_TXRST | \ + ZYNQ_UART_CR_RXRST, ®s->control); + writel(ZYNQ_UART_MR_PARITY_NONE, ®s->mode); /* 8 bit, no parity */ + uart_zynq_serial_setbrg(port); + + return 0; +} + +static void uart_zynq_serial_putc(const char c, const int port) +{ + struct uart_zynq *regs = uart_zynq_ports[port]; + + while ((readl(®s->channel_sts) & ZYNQ_UART_SR_TXFULL) != 0) + WATCHDOG_RESET(); + + if (c == '\n') { + writel('\r', ®s->tx_rx_fifo); + while ((readl(®s->channel_sts) & ZYNQ_UART_SR_TXFULL) != 0) + WATCHDOG_RESET(); + } + writel(c, ®s->tx_rx_fifo); +} + +static void uart_zynq_serial_puts(const char *s, const int port) +{ + while (*s) + uart_zynq_serial_putc(*s++, port); +} + +static int uart_zynq_serial_tstc(const int port) +{ + struct uart_zynq *regs = uart_zynq_ports[port]; + + return (readl(®s->channel_sts) & ZYNQ_UART_SR_RXEMPTY) == 0; +} + +static int uart_zynq_serial_getc(const int port) +{ + struct uart_zynq *regs = uart_zynq_ports[port]; + + while (!uart_zynq_serial_tstc(port)) + WATCHDOG_RESET(); + return readl(®s->tx_rx_fifo); +} + +#if !defined(CONFIG_SERIAL_MULTI) +int serial_init(void) +{ + return uart_zynq_serial_init(0); +} + +void serial_setbrg(void) +{ + uart_zynq_serial_setbrg(0); +} + +void serial_putc(const char c) +{ + uart_zynq_serial_putc(c, 0); +} + +void serial_puts(const char *s) +{ + uart_zynq_serial_puts(s, 0); +} + +int serial_getc(void) +{ + return uart_zynq_serial_getc(0); +} + +int serial_tstc(void) +{ + return uart_zynq_serial_tstc(0); +} +#else +/* Multi serial device functions */ +#define DECLARE_PSSERIAL_FUNCTIONS(port) \ + int uart_zynq##port##_init(void) \ + { return uart_zynq_serial_init(port); } \ + void uart_zynq##port##_setbrg(void) \ + { return uart_zynq_serial_setbrg(port); } \ + int uart_zynq##port##_getc(void) \ + { return uart_zynq_serial_getc(port); } \ + int uart_zynq##port##_tstc(void) \ + { return uart_zynq_serial_tstc(port); } \ + void uart_zynq##port##_putc(const char c) \ + { uart_zynq_serial_putc(c, port); } \ + void uart_zynq##port##_puts(const char *s) \ + { uart_zynq_serial_puts(s, port); } + +/* Serial device descriptor */ +#define INIT_PSSERIAL_STRUCTURE(port, __name) { \ + .name = __name, \ + .init = uart_zynq##port##_init, \ + .uninit = NULL, \ + .setbrg = uart_zynq##port##_setbrg, \ + .getc = uart_zynq##port##_getc, \ + .tstc = uart_zynq##port##_tstc, \ + .putc = uart_zynq##port##_putc, \ + .puts = uart_zynq##port##_puts, \ +} + +DECLARE_PSSERIAL_FUNCTIONS(0); +struct serial_device uart_zynq_serial0_device = + INIT_PSSERIAL_STRUCTURE(0, "ttyPS0"); +DECLARE_PSSERIAL_FUNCTIONS(1); +struct serial_device uart_zynq_serial1_device = + INIT_PSSERIAL_STRUCTURE(1, "ttyPS1"); + +__weak struct serial_device *default_serial_console(void) +{ + if (uart_zynq_ports[0]) + return &uart_zynq_serial0_device; + if (uart_zynq_ports[1]) + return &uart_zynq_serial1_device; + + return NULL; +} +#endif |