x86, mrst: remove Moorestown specific serial drivers

Intel Moorestown platform support was removed few years ago. This is a follow
up which removes Moorestown specific code for the serial devices. It includes
mrst_max3110 and earlyprintk bits.

This was used on SFI (Medfield, Clovertrail) based platforms as well, though
new ones use normal serial interface for the console service.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: David Cohen <david.a.cohen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/x86/include/asm/intel-mid.h

@@ -136,9 +136,6 @@ extern enum intel_mid_timer_options intel_mid_timer_options;
 #define SFI_MTMR_MAX_NUM 8
 #define SFI_MRTC_MAX	8
 
-extern struct console early_mrst_console;
-extern void mrst_early_console_init(void);
-
 extern struct console early_hsu_console;
 extern void hsu_early_console_init(const char *);
 

arch/x86/kernel/early_printk.c

@@ -226,11 +226,6 @@ static int __init setup_early_printk(char *buf)
 			early_console_register(&xenboot_console, keep);
 #endif
 #ifdef CONFIG_EARLY_PRINTK_INTEL_MID
-		if (!strncmp(buf, "mrst", 4)) {
-			mrst_early_console_init();
-			early_console_register(&early_mrst_console, keep);
-		}
-
 		if (!strncmp(buf, "hsu", 3)) {
 			hsu_early_console_init(buf + 3);
 			early_console_register(&early_hsu_console, keep);

arch/x86/platform/intel-mid/device_libs/Makefile

@@ -16,8 +16,6 @@ obj-$(subst m,y,$(CONFIG_INPUT_MPU3050)) += platform_mpu3050.o
 obj-$(subst m,y,$(CONFIG_INPUT_BMA150)) += platform_bma023.o
 obj-$(subst m,y,$(CONFIG_GPIO_PCA953X)) += platform_tca6416.o
 obj-$(subst m,y,$(CONFIG_DRM_MEDFIELD)) += platform_tc35876x.o
-# SPI Devices
-obj-$(subst m,y,$(CONFIG_SERIAL_MRST_MAX3110)) += platform_max3111.o
 # MISC Devices
 obj-$(subst m,y,$(CONFIG_KEYBOARD_GPIO)) += platform_gpio_keys.o
 obj-$(subst m,y,$(CONFIG_INTEL_MID_WATCHDOG)) += platform_wdt.o

arch/x86/platform/intel-mid/device_libs/platform_max3111.c

-/*
- * platform_max3111.c: max3111 platform data initilization file
- *
- * (C) Copyright 2013 Intel Corporation
- * Author: Sathyanarayanan Kuppuswamy <sathyanarayanan.kuppuswamy@intel.com>
- *
- * 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; version 2
- * of the License.
- */
-
-#include <linux/gpio.h>
-#include <linux/spi/spi.h>
-#include <asm/intel-mid.h>
-
-static void __init *max3111_platform_data(void *info)
-{
-	struct spi_board_info *spi_info = info;
-	int intr = get_gpio_by_name("max3111_int");
-
-	spi_info->mode = SPI_MODE_0;
-	if (intr == -1)
-		return NULL;
-	spi_info->irq = intr + INTEL_MID_IRQ_OFFSET;
-	return NULL;
-}
-
-static const struct devs_id max3111_dev_id __initconst = {
-	.name = "spi_max3111",
-	.type = SFI_DEV_TYPE_SPI,
-	.get_platform_data = &max3111_platform_data,
-};
-
-sfi_device(max3111_dev_id);

arch/x86/platform/intel-mid/early_printk_intel_mid.c

@@ -10,15 +10,13 @@
  */
 
 /*
- * This file implements two early consoles named mrst and hsu.
- * mrst is based on Maxim3110 spi-uart device, it exists in both
- * Moorestown and Medfield platforms, while hsu is based on a High
- * Speed UART device which only exists in the Medfield platform
+ * This file implements early console named hsu.
+ * hsu is based on a High Speed UART device which only exists in the Medfield
+ * platform
  */
 
 #include <linux/serial_reg.h>
 #include <linux/serial_mfd.h>
-#include <linux/kmsg_dump.h>
 #include <linux/console.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
@@ -28,216 +26,6 @@
 #include <asm/pgtable.h>
 #include <asm/intel-mid.h>
 
-#define MRST_SPI_TIMEOUT		0x200000
-#define MRST_REGBASE_SPI0		0xff128000
-#define MRST_REGBASE_SPI1		0xff128400
-#define MRST_CLK_SPI0_REG		0xff11d86c
-
-/* Bit fields in CTRLR0 */
-#define SPI_DFS_OFFSET			0
-
-#define SPI_FRF_OFFSET			4
-#define SPI_FRF_SPI			0x0
-#define SPI_FRF_SSP			0x1
-#define SPI_FRF_MICROWIRE		0x2
-#define SPI_FRF_RESV			0x3
-
-#define SPI_MODE_OFFSET			6
-#define SPI_SCPH_OFFSET			6
-#define SPI_SCOL_OFFSET			7
-#define SPI_TMOD_OFFSET			8
-#define	SPI_TMOD_TR			0x0		/* xmit & recv */
-#define SPI_TMOD_TO			0x1		/* xmit only */
-#define SPI_TMOD_RO			0x2		/* recv only */
-#define SPI_TMOD_EPROMREAD		0x3		/* eeprom read mode */
-
-#define SPI_SLVOE_OFFSET		10
-#define SPI_SRL_OFFSET			11
-#define SPI_CFS_OFFSET			12
-
-/* Bit fields in SR, 7 bits */
-#define SR_MASK				0x7f		/* cover 7 bits */
-#define SR_BUSY				(1 << 0)
-#define SR_TF_NOT_FULL			(1 << 1)
-#define SR_TF_EMPT			(1 << 2)
-#define SR_RF_NOT_EMPT			(1 << 3)
-#define SR_RF_FULL			(1 << 4)
-#define SR_TX_ERR			(1 << 5)
-#define SR_DCOL				(1 << 6)
-
-struct dw_spi_reg {
-	u32	ctrl0;
-	u32	ctrl1;
-	u32	ssienr;
-	u32	mwcr;
-	u32	ser;
-	u32	baudr;
-	u32	txfltr;
-	u32	rxfltr;
-	u32	txflr;
-	u32	rxflr;
-	u32	sr;
-	u32	imr;
-	u32	isr;
-	u32	risr;
-	u32	txoicr;
-	u32	rxoicr;
-	u32	rxuicr;
-	u32	msticr;
-	u32	icr;
-	u32	dmacr;
-	u32	dmatdlr;
-	u32	dmardlr;
-	u32	idr;
-	u32	version;
-
-	/* Currently operates as 32 bits, though only the low 16 bits matter */
-	u32	dr;
-} __packed;
-
-#define dw_readl(dw, name)		__raw_readl(&(dw)->name)
-#define dw_writel(dw, name, val)	__raw_writel((val), &(dw)->name)
-
-/* Default use SPI0 register for mrst, we will detect Penwell and use SPI1 */
-static unsigned long mrst_spi_paddr = MRST_REGBASE_SPI0;
-
-static u32 *pclk_spi0;
-/* Always contains an accessible address, start with 0 */
-static struct dw_spi_reg *pspi;
-
-static struct kmsg_dumper dw_dumper;
-static int dumper_registered;
-
-static void dw_kmsg_dump(struct kmsg_dumper *dumper,
-			 enum kmsg_dump_reason reason)
-{
-	static char line[1024];
-	size_t len;
-
-	/* When run to this, we'd better re-init the HW */
-	mrst_early_console_init();
-
-	while (kmsg_dump_get_line(dumper, true, line, sizeof(line), &len))
-		early_mrst_console.write(&early_mrst_console, line, len);
-}
-
-/* Set the ratio rate to 115200, 8n1, IRQ disabled */
-static void max3110_write_config(void)
-{
-	u16 config;
-
-	config = 0xc001;
-	dw_writel(pspi, dr, config);
-}
-
-/* Translate char to a eligible word and send to max3110 */
-static void max3110_write_data(char c)
-{
-	u16 data;
-
-	data = 0x8000 | c;
-	dw_writel(pspi, dr, data);
-}
-
-void mrst_early_console_init(void)
-{
-	u32 ctrlr0 = 0;
-	u32 spi0_cdiv;
-	u32 freq; /* Freqency info only need be searched once */
-
-	/* Base clk is 100 MHz, the actual clk = 100M / (clk_divider + 1) */
-	pclk_spi0 = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
-							MRST_CLK_SPI0_REG);
-	spi0_cdiv = ((*pclk_spi0) & 0xe00) >> 9;
-	freq = 100000000 / (spi0_cdiv + 1);
-
-	if (intel_mid_identify_cpu() == INTEL_MID_CPU_CHIP_PENWELL)
-		mrst_spi_paddr = MRST_REGBASE_SPI1;
-
-	pspi = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE,
-						mrst_spi_paddr);
-
-	/* Disable SPI controller */
-	dw_writel(pspi, ssienr, 0);
-
-	/* Set control param, 8 bits, transmit only mode */
-	ctrlr0 = dw_readl(pspi, ctrl0);
-
-	ctrlr0 &= 0xfcc0;
-	ctrlr0 |= 0xf | (SPI_FRF_SPI << SPI_FRF_OFFSET)
-		      | (SPI_TMOD_TO << SPI_TMOD_OFFSET);
-	dw_writel(pspi, ctrl0, ctrlr0);
-
-	/*
-	 * Change the spi0 clk to comply with 115200 bps, use 100000 to
-	 * calculate the clk dividor to make the clock a little slower
-	 * than real baud rate.
-	 */
-	dw_writel(pspi, baudr, freq/100000);
-
-	/* Disable all INT for early phase */
-	dw_writel(pspi, imr, 0x0);
-
-	/* Set the cs to spi-uart */
-	dw_writel(pspi, ser, 0x2);
-
-	/* Enable the HW, the last step for HW init */
-	dw_writel(pspi, ssienr, 0x1);
-
-	/* Set the default configuration */
-	max3110_write_config();
-
-	/* Register the kmsg dumper */
-	if (!dumper_registered) {
-		dw_dumper.dump = dw_kmsg_dump;
-		kmsg_dump_register(&dw_dumper);
-		dumper_registered = 1;
-	}
-}
-
-/* Slave select should be called in the read/write function */
-static void early_mrst_spi_putc(char c)
-{
-	unsigned int timeout;
-	u32 sr;
-
-	timeout = MRST_SPI_TIMEOUT;
-	/* Early putc needs to make sure the TX FIFO is not full */
-	while (--timeout) {
-		sr = dw_readl(pspi, sr);
-		if (!(sr & SR_TF_NOT_FULL))
-			cpu_relax();
-		else
-			break;
-	}
-
-	if (!timeout)
-		pr_warn("MRST earlycon: timed out\n");
-	else
-		max3110_write_data(c);
-}
-
-/* Early SPI only uses polling mode */
-static void early_mrst_spi_write(struct console *con, const char *str,
-					unsigned n)
-{
-	int i;
-
-	for (i = 0; i < n && *str; i++) {
-		if (*str == '\n')
-			early_mrst_spi_putc('\r');
-		early_mrst_spi_putc(*str);
-		str++;
-	}
-}
-
-struct console early_mrst_console = {
-	.name =		"earlymrst",
-	.write =	early_mrst_spi_write,
-	.flags =	CON_PRINTBUFFER,
-	.index =	-1,
-};
-
 /*
  * Following is the early console based on Medfield HSU (High
  * Speed UART) device.
@@ -259,7 +47,7 @@ void hsu_early_console_init(const char *s)
 		port = clamp_val(port, 0, 2);
 
 	paddr = HSU_PORT_BASE + port * 0x80;
-	phsu = (void *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE, paddr);
+	phsu = (void __iomem *)set_fixmap_offset_nocache(FIX_EARLYCON_MEM_BASE, paddr);
 
 	/* Disable FIFO */
 	writeb(0x0, phsu + UART_FCR);

drivers/tty/serial/Kconfig

@@ -482,16 +482,6 @@ config SERIAL_SA1100_CONSOLE
 	  your boot loader (lilo or loadlin) about how to pass options to the
 	  kernel at boot time.)
 
-config SERIAL_MRST_MAX3110
-	tristate "SPI UART driver for Max3110"
-	depends on SPI_DW_PCI
-	select SERIAL_CORE
-	select SERIAL_CORE_CONSOLE
-	help
-	  This is the UART protocol driver for the MAX3110 device on
-	  the Intel Moorestown platform. On other systems use the max3100
-	  driver.
-
 config SERIAL_MFD_HSU
 	tristate "Medfield High Speed UART support"
 	depends on PCI

drivers/tty/serial/Makefile

@@ -77,7 +77,6 @@ obj-$(CONFIG_SERIAL_TIMBERDALE)	+= timbuart.o
 obj-$(CONFIG_SERIAL_GRLIB_GAISLER_APBUART) += apbuart.o
 obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
 obj-$(CONFIG_SERIAL_VT8500) += vt8500_serial.o
-obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
 obj-$(CONFIG_SERIAL_MFD_HSU)	+= mfd.o
 obj-$(CONFIG_SERIAL_IFX6X60)  	+= ifx6x60.o
 obj-$(CONFIG_SERIAL_PCH_UART)	+= pch_uart.o

drivers/tty/serial/mrst_max3110.c

-/*
- *  mrst_max3110.c - spi uart protocol driver for Maxim 3110
- *
- * Copyright (c) 2008-2010, Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope 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.,
- * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-/*
- * Note:
- * 1. From Max3110 spec, the Rx FIFO has 8 words, while the Tx FIFO only has
- *    1 word. If SPI master controller doesn't support sclk frequency change,
- *    then the char need be sent out one by one with some delay
- *
- * 2. Currently only RX available interrupt is used, no need for waiting TXE
- *    interrupt for a low speed UART device
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#ifdef CONFIG_MAGIC_SYSRQ
-#define SUPPORT_SYSRQ
-#endif
-
-#include <linux/module.h>
-#include <linux/ioport.h>
-#include <linux/irq.h>
-#include <linux/init.h>
-#include <linux/console.h>
-#include <linux/tty.h>
-#include <linux/tty_flip.h>
-#include <linux/serial_core.h>
-#include <linux/serial_reg.h>
-
-#include <linux/kthread.h>
-#include <linux/spi/spi.h>
-#include <linux/pm.h>
-
-#include "mrst_max3110.h"
-
-#define UART_TX_NEEDED 1
-#define CON_TX_NEEDED  2
-#define BIT_IRQ_PENDING    3
-
-struct uart_max3110 {
-	struct uart_port port;
-	struct spi_device *spi;
-	char name[SPI_NAME_SIZE];
-
-	wait_queue_head_t wq;
-	struct task_struct *main_thread;
-	struct task_struct *read_thread;
-	struct mutex thread_mutex;
-	struct mutex io_mutex;
-
-	u32 baud;
-	u16 cur_conf;
-	u8 clock;
-	u8 parity, word_7bits;
-	u16 irq;
-
-	unsigned long uart_flags;
-
-	/* console related */
-	struct circ_buf con_xmit;
-};
-
-/* global data structure, may need be removed */
-static struct uart_max3110 *pmax;
-
-static int receive_chars(struct uart_max3110 *max,
-				unsigned short *str, int len);
-static int max3110_read_multi(struct uart_max3110 *max);
-static void max3110_con_receive(struct uart_max3110 *max);
-
-static int max3110_write_then_read(struct uart_max3110 *max,
-		const void *txbuf, void *rxbuf, unsigned len, int always_fast)
-{
-	struct spi_device *spi = max->spi;
-	struct spi_message	message;
-	struct spi_transfer	x;
-	int ret;
-
-	mutex_lock(&max->io_mutex);
-	spi_message_init(&message);
-	memset(&x, 0, sizeof x);
-	x.len = len;
-	x.tx_buf = txbuf;
-	x.rx_buf = rxbuf;
-	spi_message_add_tail(&x, &message);
-
-	if (always_fast)
-		x.speed_hz = spi->max_speed_hz;
-	else if (max->baud)
-		x.speed_hz = max->baud;
-
-	/* Do the i/o */
-	ret = spi_sync(spi, &message);
-	mutex_unlock(&max->io_mutex);
-	return ret;
-}
-
-/* Write a 16b word to the device */
-static int max3110_out(struct uart_max3110 *max, const u16 out)
-{
-	void *buf;
-	u16 *obuf, *ibuf;
-	int ret;
-
-	buf = kzalloc(8, GFP_KERNEL | GFP_DMA);
-	if (!buf)
-		return -ENOMEM;
-
-	obuf = buf;
-	ibuf = buf + 4;
-	*obuf = out;
-	ret = max3110_write_then_read(max, obuf, ibuf, 2, 1);
-	if (ret) {
-		pr_warn("%s: get err msg %d when sending 0x%x\n",
-			__func__, ret, out);
-		goto exit;
-	}
-
-	receive_chars(max, ibuf, 1);
-
-exit:
-	kfree(buf);
-	return ret;
-}
-
-/*
- * This is usually used to read data from SPIC RX FIFO, which doesn't
- * need any delay like flushing character out.
- *
- * Return how many valide bytes are read back
- */
-static int max3110_read_multi(struct uart_max3110 *max)
-{
-	void *buf;
-	u16 *obuf, *ibuf;
-	int ret, blen;
-
-	blen = M3110_RX_FIFO_DEPTH * sizeof(u16);
-	buf = kzalloc(blen * 2, GFP_KERNEL | GFP_DMA);
-	if (!buf)
-		return 0;
-
-	/* tx/rx always have the same length */
-	obuf = buf;
-	ibuf = buf + blen;
-
-	if (max3110_write_then_read(max, obuf, ibuf, blen, 1)) {
-		kfree(buf);
-		return 0;
-	}
-
-	ret = receive_chars(max, ibuf, M3110_RX_FIFO_DEPTH);
-
-	kfree(buf);
-	return ret;
-}
-
-static void serial_m3110_con_putchar(struct uart_port *port, int ch)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	struct circ_buf *xmit = &max->con_xmit;
-
-	if (uart_circ_chars_free(xmit)) {
-		xmit->buf[xmit->head] = (char)ch;
-		xmit->head = (xmit->head + 1) & (PAGE_SIZE - 1);
-	}
-}
-
-/*
- * Print a string to the serial port trying not to disturb
- * any possible real use of the port...
- *
- *	The console_lock must be held when we get here.
- */
-static void serial_m3110_con_write(struct console *co,
-				const char *s, unsigned int count)
-{
-	if (!pmax)
-		return;
-
-	uart_console_write(&pmax->port, s, count, serial_m3110_con_putchar);
-
-	if (!test_and_set_bit(CON_TX_NEEDED, &pmax->uart_flags))
-		wake_up(&pmax->wq);
-}
-
-static int __init
-serial_m3110_con_setup(struct console *co, char *options)
-{
-	struct uart_max3110 *max = pmax;
-	int baud = 115200;
-	int bits = 8;
-	int parity = 'n';
-	int flow = 'n';
-
-	pr_info("setting up console\n");
-
-	if (co->index == -1)
-		co->index = 0;
-
-	if (!max) {
-		pr_err("pmax is NULL, return\n");
-		return -ENODEV;
-	}
-
-	if (options)
-		uart_parse_options(options, &baud, &parity, &bits, &flow);
-
-	return uart_set_options(&max->port, co, baud, parity, bits, flow);
-}
-
-static struct tty_driver *serial_m3110_con_device(struct console *co,
-							int *index)
-{
-	struct uart_driver *p = co->data;
-	*index = co->index;
-	return p->tty_driver;
-}
-
-static struct uart_driver serial_m3110_reg;
-static struct console serial_m3110_console = {
-	.name		= "ttyS",
-	.write		= serial_m3110_con_write,
-	.device		= serial_m3110_con_device,
-	.setup		= serial_m3110_con_setup,
-	.flags		= CON_PRINTBUFFER,
-	.index		= -1,
-	.data		= &serial_m3110_reg,
-};
-
-static unsigned int serial_m3110_tx_empty(struct uart_port *port)
-{
-	return 1;
-}
-
-static void serial_m3110_stop_tx(struct uart_port *port)
-{
-	return;
-}
-
-/* stop_rx will be called in spin_lock env */
-static void serial_m3110_stop_rx(struct uart_port *port)
-{
-	return;
-}
-
-#define WORDS_PER_XFER	128
-static void send_circ_buf(struct uart_max3110 *max,
-				struct circ_buf *xmit)
-{
-	void *buf;
-	u16 *obuf, *ibuf;
-	int i, len, blen, dma_size, left, ret = 0;
-
-
-	dma_size = WORDS_PER_XFER * sizeof(u16) * 2;
-	buf = kzalloc(dma_size, GFP_KERNEL | GFP_DMA);
-	if (!buf)
-		return;
-	obuf = buf;
-	ibuf = buf + dma_size/2;
-
-	while (!uart_circ_empty(xmit)) {
-		left = uart_circ_chars_pending(xmit);
-		while (left) {
-			len = min(left, WORDS_PER_XFER);
-			blen = len * sizeof(u16);
-			memset(ibuf, 0, blen);
-
-			for (i = 0; i < len; i++) {
-				obuf[i] = (u8)xmit->buf[xmit->tail] | WD_TAG;
-				xmit->tail = (xmit->tail + 1) &
-						(UART_XMIT_SIZE - 1);
-			}
-
-			/* Fail to send msg to console is not very critical */
-
-			ret = max3110_write_then_read(max, obuf, ibuf, blen, 0);
-			if (ret)
-				pr_warn("%s: get err msg %d\n", __func__, ret);
-
-			receive_chars(max, ibuf, len);
-
-			max->port.icount.tx += len;
-			left -= len;
-		}
-	}
-
-	kfree(buf);
-}
-
-static void transmit_char(struct uart_max3110 *max)
-{
-	struct uart_port *port = &max->port;
-	struct circ_buf *xmit = &port->state->xmit;
-
-	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
-		return;
-
-	send_circ_buf(max, xmit);
-
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
-		uart_write_wakeup(port);
-
-	if (uart_circ_empty(xmit))
-		serial_m3110_stop_tx(port);
-}
-
-/*
- * This will be called by uart_write() and tty_write, can't
- * go to sleep
- */
-static void serial_m3110_start_tx(struct uart_port *port)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-
-	if (!test_and_set_bit(UART_TX_NEEDED, &max->uart_flags))
-		wake_up(&max->wq);
-}
-
-static int
-receive_chars(struct uart_max3110 *max, unsigned short *str, int len)
-{
-	struct uart_port *port = &max->port;
-	struct tty_port *tport;
-	char buf[M3110_RX_FIFO_DEPTH];
-	int r, w, usable;
-
-	/* If uart is not opened, just return */
-	if (!port->state)
-		return 0;
-
-	tport = &port->state->port;
-
-	for (r = 0, w = 0; r < len; r++) {
-		if (str[r] & MAX3110_BREAK &&
-		    uart_handle_break(port))
-			continue;
-
-		if (str[r] & MAX3110_READ_DATA_AVAILABLE) {
-			if (uart_handle_sysrq_char(port, str[r] & 0xff))
-				continue;
-
-			buf[w++] = str[r] & 0xff;
-		}
-	}
-
-	if (!w)
-		return 0;
-
-	for (r = 0; w; r += usable, w -= usable) {
-		usable = tty_buffer_request_room(tport, w);
-		if (usable) {
-			tty_insert_flip_string(tport, buf + r, usable);
-			port->icount.rx += usable;
-		}
-	}
-	tty_flip_buffer_push(tport);
-
-	return r;
-}
-
-/*
- * This routine will be used in read_thread or RX IRQ handling,
- * it will first do one round buffer read(8 words), if there is some
- * valid RX data, will try to read 5 more rounds till all data
- * is read out.
- *
- * Use stack space as data buffer to save some system load, and chose
- * 504 Btyes as a threadhold to do a bulk push to upper tty layer when
- * receiving bulk data, a much bigger buffer may cause stack overflow
- */
-static void max3110_con_receive(struct uart_max3110 *max)
-{
-	int loop = 1, num;
-
-	do {
-		num = max3110_read_multi(max);
-
-		if (num) {
-			loop = 5;
-		}
-	} while (--loop);
-}
-
-static int max3110_main_thread(void *_max)
-{
-	struct uart_max3110 *max = _max;
-	wait_queue_head_t *wq = &max->wq;
-	int ret = 0;
-	struct circ_buf *xmit = &max->con_xmit;
-
-	pr_info("start main thread\n");
-
-	do {
-		wait_event_interruptible(*wq,
-				max->uart_flags || kthread_should_stop());
-
-		mutex_lock(&max->thread_mutex);
-
-		if (test_and_clear_bit(BIT_IRQ_PENDING, &max->uart_flags))
-			max3110_con_receive(max);
-
-		/* first handle console output */
-		if (test_and_clear_bit(CON_TX_NEEDED, &max->uart_flags))
-			send_circ_buf(max, xmit);
-
-		/* handle uart output */
-		if (test_and_clear_bit(UART_TX_NEEDED, &max->uart_flags))
-			transmit_char(max);
-
-		mutex_unlock(&max->thread_mutex);
-
-	} while (!kthread_should_stop());
-
-	return ret;
-}
-
-static irqreturn_t serial_m3110_irq(int irq, void *dev_id)
-{
-	struct uart_max3110 *max = dev_id;
-
-	/* max3110's irq is a falling edge, not level triggered,
-	 * so no need to disable the irq */
-
-	if (!test_and_set_bit(BIT_IRQ_PENDING, &max->uart_flags))
-		wake_up(&max->wq);
-
-	return IRQ_HANDLED;
-}
-
-/* if don't use RX IRQ, then need a thread to polling read */
-static int max3110_read_thread(void *_max)
-{
-	struct uart_max3110 *max = _max;
-
-	pr_info("start read thread\n");
-	do {
-		/*
-		 * If can't acquire the mutex, it means the main thread
-		 * is running which will also perform the rx job
-		 */
-		if (mutex_trylock(&max->thread_mutex)) {
-			max3110_con_receive(max);
-			mutex_unlock(&max->thread_mutex);
-		}
-
-		set_current_state(TASK_INTERRUPTIBLE);
-		schedule_timeout(HZ / 20);
-	} while (!kthread_should_stop());
-
-	return 0;
-}
-
-static int serial_m3110_startup(struct uart_port *port)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	u16 config = 0;
-	int ret = 0;
-
-	if (port->line != 0) {
-		pr_err("uart port startup failed\n");
-		return -1;
-	}
-
-	/* Disable all IRQ and config it to 115200, 8n1 */
-	config = WC_TAG | WC_FIFO_ENABLE
-			| WC_1_STOPBITS
-			| WC_8BIT_WORD
-			| WC_BAUD_DR2;
-
-	/* as we use thread to handle tx/rx, need set low latency */
-	port->state->port.low_latency = 1;
-
-	if (max->irq) {
-		/* Enable RX IRQ only */
-		config |= WC_RXA_IRQ_ENABLE;
-	} else {
-		/* If IRQ is disabled, start a read thread for input data */
-		max->read_thread =
-			kthread_run(max3110_read_thread, max, "max3110_read");
-		if (IS_ERR(max->read_thread)) {
-			ret = PTR_ERR(max->read_thread);
-			max->read_thread = NULL;
-			pr_err("Can't create read thread!\n");
-			return ret;
-		}
-	}
-
-	ret = max3110_out(max, config);
-	if (ret) {
-		if (max->read_thread)
-			kthread_stop(max->read_thread);
-		max->read_thread = NULL;
-		return ret;
-	}
-
-	max->cur_conf = config;
-	return 0;
-}
-
-static void serial_m3110_shutdown(struct uart_port *port)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	u16 config;
-
-	if (max->read_thread) {
-		kthread_stop(max->read_thread);
-		max->read_thread = NULL;
-	}
-
-	/* Disable interrupts from this port */
-	config = WC_TAG | WC_SW_SHDI;
-	max3110_out(max, config);
-}
-
-static void serial_m3110_release_port(struct uart_port *port)
-{
-}
-
-static int serial_m3110_request_port(struct uart_port *port)
-{
-	return 0;
-}
-
-static void serial_m3110_config_port(struct uart_port *port, int flags)
-{
-	port->type = PORT_MAX3100;
-}
-
-static int
-serial_m3110_verify_port(struct uart_port *port, struct serial_struct *ser)
-{
-	/* we don't want the core code to modify any port params */
-	return -EINVAL;
-}
-
-
-static const char *serial_m3110_type(struct uart_port *port)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	return max->name;
-}
-
-static void
-serial_m3110_set_termios(struct uart_port *port, struct ktermios *termios,
-		       struct ktermios *old)
-{
-	struct uart_max3110 *max =
-		container_of(port, struct uart_max3110, port);
-	unsigned char cval;
-	unsigned int baud, parity = 0;
-	int clk_div = -1;
-	u16 new_conf = max->cur_conf;
-
-	switch (termios->c_cflag & CSIZE) {
-	case CS7:
-		cval = UART_LCR_WLEN7;
-		new_conf |= WC_7BIT_WORD;
-		break;
-	default:
-		/* We only support CS7 & CS8 */
-		termios->c_cflag &= ~CSIZE;
-		termios->c_cflag |= CS8;
-	case CS8:
-		cval = UART_LCR_WLEN8;
-		new_conf |= WC_8BIT_WORD;
-		break;
-	}
-
-	baud = uart_get_baud_rate(port, termios, old, 0, 230400);
-
-	/* First calc the div for 1.8MHZ clock case */
-	switch (baud) {
-	case 300:
-		clk_div = WC_BAUD_DR384;
-		break;
-	case 600:
-		clk_div = WC_BAUD_DR192;
-		break;
-	case 1200:
-		clk_div = WC_BAUD_DR96;
-		break;
-	case 2400:
-		clk_div = WC_BAUD_DR48;
-		break;
-	case 4800:
-		clk_div = WC_BAUD_DR24;
-		break;
-	case 9600:
-		clk_div = WC_BAUD_DR12;
-		break;
-	case 19200:
-		clk_div = WC_BAUD_DR6;
-		break;
-	case 38400:
-		clk_div = WC_BAUD_DR3;
-		break;
-	case 57600:
-		clk_div = WC_BAUD_DR2;
-		break;
-	case 115200:
-		clk_div = WC_BAUD_DR1;
-		break;
-	case 230400:
-		if (max->clock & MAX3110_HIGH_CLK)
-			break;
-	default:
-		/* Pick the previous baud rate */
-		baud = max->baud;
-		clk_div = max->cur_conf & WC_BAUD_DIV_MASK;
-		tty_termios_encode_baud_rate(termios, baud, baud);
-	}
-
-	if (max->clock & MAX3110_HIGH_CLK) {
-		clk_div += 1;
-		/* High clk version max3110 doesn't support B300 */
-		if (baud == 300) {
-			baud = 600;
-			clk_div = WC_BAUD_DR384;
-		}
-		if (baud == 230400)
-			clk_div = WC_BAUD_DR1;
-		tty_termios_encode_baud_rate(termios, baud, baud);
-	}
-
-	new_conf = (new_conf & ~WC_BAUD_DIV_MASK) | clk_div;
-
-	if (unlikely(termios->c_cflag & CMSPAR))
-		termios->c_cflag &= ~CMSPAR;
-
-	if (termios->c_cflag & CSTOPB)
-		new_conf |= WC_2_STOPBITS;
-	else
-		new_conf &= ~WC_2_STOPBITS;
-
-	if (termios->c_cflag & PARENB) {
-		new_conf |= WC_PARITY_ENABLE;
-		parity |= UART_LCR_PARITY;
-	} else
-		new_conf &= ~WC_PARITY_ENABLE;
-
-	if (!(termios->c_cflag & PARODD))
-		parity |= UART_LCR_EPAR;
-	max->parity = parity;
-
-	uart_update_timeout(port, termios->c_cflag, baud);
-
-	new_conf |= WC_TAG;
-	if (new_conf != max->cur_conf) {
-		if (!max3110_out(max, new_conf)) {
-			max->cur_conf = new_conf;
-			max->baud = baud;
-		}
-	}
-}
-
-/* Don't handle hw handshaking */
-static unsigned int serial_m3110_get_mctrl(struct uart_port *port)
-{
-	return TIOCM_DSR | TIOCM_CAR | TIOCM_DSR;
-}
-
-static void serial_m3110_set_mctrl(struct uart_port *port, unsigned int mctrl)
-{
-}
-
-static void serial_m3110_break_ctl(struct uart_port *port, int break_state)
-{
-}
-
-static void serial_m3110_pm(struct uart_port *port, unsigned int state,
-			unsigned int oldstate)
-{
-}
-
-static struct uart_ops serial_m3110_ops = {
-	.tx_empty	= serial_m3110_tx_empty,
-	.set_mctrl	= serial_m3110_set_mctrl,
-	.get_mctrl	= serial_m3110_get_mctrl,
-	.stop_tx	= serial_m3110_stop_tx,
-	.start_tx	= serial_m3110_start_tx,
-	.stop_rx	= serial_m3110_stop_rx,
-	.break_ctl	= serial_m3110_break_ctl,
-	.startup	= serial_m3110_startup,
-	.shutdown	= serial_m3110_shutdown,
-	.set_termios	= serial_m3110_set_termios,
-	.pm		= serial_m3110_pm,
-	.type		= serial_m3110_type,
-	.release_port	= serial_m3110_release_port,
-	.request_port	= serial_m3110_request_port,
-	.config_port	= serial_m3110_config_port,
-	.verify_port	= serial_m3110_verify_port,
-};
-
-static struct uart_driver serial_m3110_reg = {
-	.owner		= THIS_MODULE,
-	.driver_name	= "MRST serial",
-	.dev_name	= "ttyS",
-	.major		= TTY_MAJOR,
-	.minor		= 64,
-	.nr		= 1,
-	.cons		= &serial_m3110_console,
-};
-
-#ifdef CONFIG_PM_SLEEP
-static int serial_m3110_suspend(struct device *dev)
-{
-	struct spi_device *spi = to_spi_device(dev);
-	struct uart_max3110 *max = spi_get_drvdata(spi);
-
-	if (max->irq > 0)
-		disable_irq(max->irq);
-	uart_suspend_port(&serial_m3110_reg, &max->port);
-	max3110_out(max, max->cur_conf | WC_SW_SHDI);
-	return 0;
-}
-
-static int serial_m3110_resume(struct device *dev)
-{
-	struct spi_device *spi = to_spi_device(dev);
-	struct uart_max3110 *max = spi_get_drvdata(spi);
-
-	max3110_out(max, max->cur_conf);
-	uart_resume_port(&serial_m3110_reg, &max->port);
-	if (max->irq > 0)
-		enable_irq(max->irq);
-	return 0;
-}
-
-static SIMPLE_DEV_PM_OPS(serial_m3110_pm_ops, serial_m3110_suspend,
-			serial_m3110_resume);
-#define SERIAL_M3110_PM_OPS (&serial_m3110_pm_ops)
-
-#else
-#define SERIAL_M3110_PM_OPS NULL
-#endif
-
-static int serial_m3110_probe(struct spi_device *spi)
-{
-	struct uart_max3110 *max;
-	void *buffer;
-	u16 res;
-	int ret = 0;
-
-	max = kzalloc(sizeof(*max), GFP_KERNEL);
-	if (!max)
-		return -ENOMEM;
-
-	/* Set spi info */
-	spi->bits_per_word = 16;
-	max->clock = MAX3110_HIGH_CLK;
-
-	spi_setup(spi);
-
-	max->port.type = PORT_MAX3100;
-	max->port.fifosize = 2;		/* Only have 16b buffer */
-	max->port.ops = &serial_m3110_ops;
-	max->port.line = 0;
-	max->port.dev = &spi->dev;
-	max->port.uartclk = 115200;
-
-	max->spi = spi;
-	strcpy(max->name, spi->modalias);
-	max->irq = (u16)spi->irq;
-
-	mutex_init(&max->thread_mutex);
-	mutex_init(&max->io_mutex);
-
-	max->word_7bits = 0;
-	max->parity = 0;
-	max->baud = 0;
-
-	max->cur_conf = 0;
-	max->uart_flags = 0;
-
-	/* Check if reading configuration register returns something sane */
-
-	res = RC_TAG;
-	ret = max3110_write_then_read(max, (u8 *)&res, (u8 *)&res, 2, 0);
-	if (ret < 0 || res == 0 || res == 0xffff) {
-		dev_dbg(&spi->dev, "MAX3111 deemed not present (conf reg %04x)",
-									res);
-		ret = -ENODEV;
-		goto err_get_page;
-	}
-
-	buffer = (void *)__get_free_page(GFP_KERNEL);
-	if (!buffer) {
-		ret = -ENOMEM;
-		goto err_get_page;
-	}
-	max->con_xmit.buf = buffer;
-	max->con_xmit.head = 0;
-	max->con_xmit.tail = 0;
-
-	init_waitqueue_head(&max->wq);
-
-	max->main_thread = kthread_run(max3110_main_thread,
-					max, "max3110_main");
-	if (IS_ERR(max->main_thread)) {
-		ret = PTR_ERR(max->main_thread);
-		goto err_kthread;
-	}
-
-	if (max->irq) {
-		ret = request_irq(max->irq, serial_m3110_irq,
-				IRQ_TYPE_EDGE_FALLING, "max3110", max);
-		if (ret) {
-			max->irq = 0;
-			dev_warn(&spi->dev,
-			"unable to allocate IRQ, will use polling method\n");
-		}
-	}
-
-	spi_set_drvdata(spi, max);
-	pmax = max;
-
-	/* Give membase a psudo value to pass serial_core's check */
-	max->port.membase = (unsigned char __iomem *)0xff110000;
-	uart_add_one_port(&serial_m3110_reg, &max->port);
-
-	return 0;
-
-err_kthread:
-	free_page((unsigned long)buffer);
-err_get_page:
-	kfree(max);
-	return ret;
-}
-
-static int serial_m3110_remove(struct spi_device *dev)
-{
-	struct uart_max3110 *max = spi_get_drvdata(dev);
-
-	if (!max)
-		return 0;
-
-	uart_remove_one_port(&serial_m3110_reg, &max->port);
-
-	free_page((unsigned long)max->con_xmit.buf);
-
-	if (max->irq)
-		free_irq(max->irq, max);
-
-	if (max->main_thread)
-		kthread_stop(max->main_thread);
-
-	kfree(max);
-	return 0;
-}
-
-static struct spi_driver uart_max3110_driver = {
-	.driver = {
-			.name	= "spi_max3111",
-			.owner	= THIS_MODULE,
-			.pm	= SERIAL_M3110_PM_OPS,
-	},
-	.probe		= serial_m3110_probe,
-	.remove		= serial_m3110_remove,
-};
-
-static int __init serial_m3110_init(void)
-{
-	int ret = 0;
-
-	ret = uart_register_driver(&serial_m3110_reg);
-	if (ret)
-		return ret;
-
-	ret = spi_register_driver(&uart_max3110_driver);
-	if (ret)
-		uart_unregister_driver(&serial_m3110_reg);
-
-	return ret;
-}
-
-static void __exit serial_m3110_exit(void)
-{
-	spi_unregister_driver(&uart_max3110_driver);
-	uart_unregister_driver(&serial_m3110_reg);
-}
-
-module_init(serial_m3110_init);
-module_exit(serial_m3110_exit);
-
-MODULE_LICENSE("GPL v2");
-MODULE_ALIAS("spi:max3110-uart");

drivers/tty/serial/mrst_max3110.h

-#ifndef _MRST_MAX3110_H
-#define _MRST_MAX3110_H
-
-#define MAX3110_HIGH_CLK	0x1	/* 3.6864 MHZ */
-#define MAX3110_LOW_CLK		0x0	/* 1.8432 MHZ */
-
-/* status bits for all 4 MAX3110 operate modes */
-#define MAX3110_READ_DATA_AVAILABLE	(1 << 15)
-#define MAX3110_WRITE_BUF_EMPTY		(1 << 14)
-#define MAX3110_BREAK			(1 << 10)
-
-#define WC_TAG			(3 << 14)
-#define RC_TAG			(1 << 14)
-#define WD_TAG			(2 << 14)
-#define RD_TAG			(0 << 14)
-
-/* bits def for write configuration */
-#define WC_FIFO_ENABLE_MASK	(1 << 13)
-#define WC_FIFO_ENABLE		(0 << 13)
-
-#define WC_SW_SHDI		(1 << 12)
-
-#define WC_IRQ_MASK		(0xF << 8)
-#define WC_TXE_IRQ_ENABLE	(1 << 11)	/* TX empty irq */
-#define WC_RXA_IRQ_ENABLE	(1 << 10)	/* RX available irq */
-#define WC_PAR_HIGH_IRQ_ENABLE	(1 << 9)
-#define WC_REC_ACT_IRQ_ENABLE	(1 << 8)
-
-#define WC_IRDA_ENABLE		(1 << 7)
-
-#define WC_STOPBITS_MASK	(1 << 6)
-#define WC_2_STOPBITS		(1 << 6)
-#define WC_1_STOPBITS		(0 << 6)
-
-#define WC_PARITY_ENABLE_MASK	(1 << 5)
-#define WC_PARITY_ENABLE	(1 << 5)
-
-#define WC_WORDLEN_MASK		(1 << 4)
-#define WC_7BIT_WORD		(1 << 4)
-#define WC_8BIT_WORD		(0 << 4)
-
-#define WC_BAUD_DIV_MASK	(0xF)
-#define WC_BAUD_DR1		(0x0)
-#define WC_BAUD_DR2		(0x1)
-#define WC_BAUD_DR4		(0x2)
-#define WC_BAUD_DR8		(0x3)
-#define WC_BAUD_DR16		(0x4)
-#define WC_BAUD_DR32		(0x5)
-#define WC_BAUD_DR64		(0x6)
-#define WC_BAUD_DR128		(0x7)
-#define WC_BAUD_DR3		(0x8)
-#define WC_BAUD_DR6		(0x9)
-#define WC_BAUD_DR12		(0xA)
-#define WC_BAUD_DR24		(0xB)
-#define WC_BAUD_DR48		(0xC)
-#define WC_BAUD_DR96		(0xD)
-#define WC_BAUD_DR192		(0xE)
-#define WC_BAUD_DR384		(0xF)
-
-#define M3110_RX_FIFO_DEPTH	8
-#endif