156 lines
3.5 KiB
C
156 lines
3.5 KiB
C
/*
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* Simple CLPS711X serial driver
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*
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* (C) Copyright 2012 Alexander Shiyan <shc_work@mail.ru>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*/
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#include <common.h>
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#include <malloc.h>
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#include <init.h>
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#include <io.h>
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#include <linux/clk.h>
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#include <linux/err.h>
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#include <mfd/syscon.h>
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#include <mach/clps711x.h>
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struct clps711x_uart {
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void __iomem *UBRLCR;
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void __iomem *UARTDR;
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void __iomem *syscon;
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struct clk *uart_clk;
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struct console_device cdev;
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};
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#define SYSCON(x) ((x)->syscon + 0x00)
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#define SYSFLG(x) ((x)->syscon + 0x40)
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static int clps711x_setbaudrate(struct console_device *cdev, int baudrate)
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{
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struct clps711x_uart *s = cdev->dev->priv;
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int divisor;
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u32 tmp;
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divisor = (clk_get_rate(s->uart_clk) / 16) / baudrate;
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tmp = readl(s->UBRLCR) & ~UBRLCR_BAUD_MASK;
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tmp |= divisor - 1;
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writel(tmp, s->UBRLCR);
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return 0;
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}
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static void clps711x_init_port(struct console_device *cdev)
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{
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struct clps711x_uart *s = cdev->dev->priv;
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u32 tmp;
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/* Disable the UART */
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writel(readl(SYSCON(s)) & ~SYSCON_UARTEN, SYSCON(s));
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/* Setup Line Control Register */
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tmp = readl(s->UBRLCR) & UBRLCR_BAUD_MASK;
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tmp |= UBRLCR_FIFOEN | UBRLCR_WRDLEN8; /* FIFO on, 8N1 mode */
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writel(tmp, s->UBRLCR);
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/* Enable the UART */
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writel(readl(SYSCON(s)) | SYSCON_UARTEN, SYSCON(s));
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}
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static void clps711x_putc(struct console_device *cdev, char c)
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{
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struct clps711x_uart *s = cdev->dev->priv;
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/* Wait until there is space in the FIFO */
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while (readl(SYSFLG(s)) & SYSFLG_UTXFF)
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barrier();
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/* Send the character */
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writew(c, s->UARTDR);
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}
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static int clps711x_getc(struct console_device *cdev)
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{
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struct clps711x_uart *s = cdev->dev->priv;
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u16 data;
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/* Wait until there is data in the FIFO */
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while (readl(SYSFLG(s)) & SYSFLG_URXFE)
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barrier();
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data = readw(s->UARTDR);
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/* Check for an error flag */
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if (data & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR))
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return -1;
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return (int)data;
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}
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static int clps711x_tstc(struct console_device *cdev)
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{
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struct clps711x_uart *s = cdev->dev->priv;
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return !(readl(SYSFLG(s)) & SYSFLG_URXFE);
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}
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static void clps711x_flush(struct console_device *cdev)
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{
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struct clps711x_uart *s = cdev->dev->priv;
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while (readl(SYSFLG(s)) & SYSFLG_UBUSY)
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barrier();
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}
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static int clps711x_probe(struct device_d *dev)
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{
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struct clps711x_uart *s;
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char syscon_dev[18];
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BUG_ON(dev->num_resources != 2);
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BUG_ON((dev->id != 0) && (dev->id != 1));
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s = xzalloc(sizeof(struct clps711x_uart));
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s->uart_clk = clk_get(dev, NULL);
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BUG_ON(IS_ERR(s->uart_clk));
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s->UBRLCR = dev_get_mem_region(dev, 0);
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s->UARTDR = dev_get_mem_region(dev, 1);
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sprintf(syscon_dev, "clps711x-syscon%i", dev->id + 1);
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s->syscon = syscon_base_lookup_by_pdevname(syscon_dev);
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BUG_ON(IS_ERR(s->syscon));
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dev->priv = s;
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s->cdev.dev = dev;
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s->cdev.tstc = clps711x_tstc;
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s->cdev.putc = clps711x_putc;
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s->cdev.getc = clps711x_getc;
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s->cdev.flush = clps711x_flush;
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s->cdev.setbrg = clps711x_setbaudrate;
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clps711x_init_port(&s->cdev);
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return console_register(&s->cdev);
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}
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static void clps711x_remove(struct device_d *dev)
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{
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struct clps711x_uart *s = dev->priv;
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clps711x_flush(&s->cdev);
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console_unregister(&s->cdev);
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free(s);
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}
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static struct driver_d clps711x_driver = {
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.name = "clps711x_serial",
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.probe = clps711x_probe,
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.remove = clps711x_remove,
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};
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console_platform_driver(clps711x_driver);
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