518 lines
11 KiB
C
518 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* SH SPI bus driver
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*
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* Copyright (C) 2011 Renesas Solutions Corp.
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*
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* Based on pxa2xx_spi.c:
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* Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/sched.h>
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#include <linux/errno.h>
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#include <linux/timer.h>
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#include <linux/delay.h>
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#include <linux/list.h>
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#include <linux/workqueue.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/io.h>
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#include <linux/spi/spi.h>
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#define SPI_SH_TBR 0x00
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#define SPI_SH_RBR 0x00
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#define SPI_SH_CR1 0x08
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#define SPI_SH_CR2 0x10
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#define SPI_SH_CR3 0x18
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#define SPI_SH_CR4 0x20
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#define SPI_SH_CR5 0x28
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/* CR1 */
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#define SPI_SH_TBE 0x80
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#define SPI_SH_TBF 0x40
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#define SPI_SH_RBE 0x20
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#define SPI_SH_RBF 0x10
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#define SPI_SH_PFONRD 0x08
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#define SPI_SH_SSDB 0x04
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#define SPI_SH_SSD 0x02
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#define SPI_SH_SSA 0x01
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/* CR2 */
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#define SPI_SH_RSTF 0x80
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#define SPI_SH_LOOPBK 0x40
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#define SPI_SH_CPOL 0x20
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#define SPI_SH_CPHA 0x10
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#define SPI_SH_L1M0 0x08
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/* CR3 */
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#define SPI_SH_MAX_BYTE 0xFF
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/* CR4 */
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#define SPI_SH_TBEI 0x80
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#define SPI_SH_TBFI 0x40
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#define SPI_SH_RBEI 0x20
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#define SPI_SH_RBFI 0x10
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#define SPI_SH_WPABRT 0x04
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#define SPI_SH_SSS 0x01
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/* CR8 */
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#define SPI_SH_P1L0 0x80
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#define SPI_SH_PP1L0 0x40
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#define SPI_SH_MUXI 0x20
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#define SPI_SH_MUXIRQ 0x10
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#define SPI_SH_FIFO_SIZE 32
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#define SPI_SH_SEND_TIMEOUT (3 * HZ)
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#define SPI_SH_RECEIVE_TIMEOUT (HZ >> 3)
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#undef DEBUG
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struct spi_sh_data {
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void __iomem *addr;
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int irq;
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struct spi_master *master;
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struct list_head queue;
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struct work_struct ws;
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unsigned long cr1;
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wait_queue_head_t wait;
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spinlock_t lock;
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int width;
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};
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static void spi_sh_write(struct spi_sh_data *ss, unsigned long data,
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unsigned long offset)
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{
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if (ss->width == 8)
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iowrite8(data, ss->addr + (offset >> 2));
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else if (ss->width == 32)
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iowrite32(data, ss->addr + offset);
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}
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static unsigned long spi_sh_read(struct spi_sh_data *ss, unsigned long offset)
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{
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if (ss->width == 8)
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return ioread8(ss->addr + (offset >> 2));
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else if (ss->width == 32)
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return ioread32(ss->addr + offset);
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else
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return 0;
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}
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static void spi_sh_set_bit(struct spi_sh_data *ss, unsigned long val,
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unsigned long offset)
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{
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unsigned long tmp;
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tmp = spi_sh_read(ss, offset);
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tmp |= val;
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spi_sh_write(ss, tmp, offset);
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}
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static void spi_sh_clear_bit(struct spi_sh_data *ss, unsigned long val,
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unsigned long offset)
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{
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unsigned long tmp;
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tmp = spi_sh_read(ss, offset);
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tmp &= ~val;
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spi_sh_write(ss, tmp, offset);
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}
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static void clear_fifo(struct spi_sh_data *ss)
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{
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spi_sh_set_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
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spi_sh_clear_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
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}
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static int spi_sh_wait_receive_buffer(struct spi_sh_data *ss)
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{
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int timeout = 100000;
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while (spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
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udelay(10);
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if (timeout-- < 0)
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return -ETIMEDOUT;
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}
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return 0;
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}
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static int spi_sh_wait_write_buffer_empty(struct spi_sh_data *ss)
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{
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int timeout = 100000;
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while (!(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBE)) {
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udelay(10);
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if (timeout-- < 0)
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return -ETIMEDOUT;
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}
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return 0;
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}
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static int spi_sh_send(struct spi_sh_data *ss, struct spi_message *mesg,
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struct spi_transfer *t)
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{
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int i, retval = 0;
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int remain = t->len;
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int cur_len;
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unsigned char *data;
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long ret;
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if (t->len)
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spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
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data = (unsigned char *)t->tx_buf;
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while (remain > 0) {
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cur_len = min(SPI_SH_FIFO_SIZE, remain);
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for (i = 0; i < cur_len &&
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!(spi_sh_read(ss, SPI_SH_CR4) &
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SPI_SH_WPABRT) &&
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!(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBF);
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i++)
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spi_sh_write(ss, (unsigned long)data[i], SPI_SH_TBR);
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if (spi_sh_read(ss, SPI_SH_CR4) & SPI_SH_WPABRT) {
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/* Abort SPI operation */
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spi_sh_set_bit(ss, SPI_SH_WPABRT, SPI_SH_CR4);
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retval = -EIO;
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break;
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}
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cur_len = i;
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remain -= cur_len;
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data += cur_len;
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if (remain > 0) {
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ss->cr1 &= ~SPI_SH_TBE;
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spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
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ret = wait_event_interruptible_timeout(ss->wait,
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ss->cr1 & SPI_SH_TBE,
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SPI_SH_SEND_TIMEOUT);
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if (ret == 0 && !(ss->cr1 & SPI_SH_TBE)) {
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printk(KERN_ERR "%s: timeout\n", __func__);
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return -ETIMEDOUT;
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}
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}
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}
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if (list_is_last(&t->transfer_list, &mesg->transfers)) {
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spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, SPI_SH_CR1);
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spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
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ss->cr1 &= ~SPI_SH_TBE;
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spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
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ret = wait_event_interruptible_timeout(ss->wait,
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ss->cr1 & SPI_SH_TBE,
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SPI_SH_SEND_TIMEOUT);
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if (ret == 0 && (ss->cr1 & SPI_SH_TBE)) {
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printk(KERN_ERR "%s: timeout\n", __func__);
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return -ETIMEDOUT;
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}
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}
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return retval;
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}
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static int spi_sh_receive(struct spi_sh_data *ss, struct spi_message *mesg,
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struct spi_transfer *t)
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{
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int i;
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int remain = t->len;
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int cur_len;
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unsigned char *data;
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long ret;
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if (t->len > SPI_SH_MAX_BYTE)
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spi_sh_write(ss, SPI_SH_MAX_BYTE, SPI_SH_CR3);
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else
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spi_sh_write(ss, t->len, SPI_SH_CR3);
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spi_sh_clear_bit(ss, SPI_SH_SSD | SPI_SH_SSDB, SPI_SH_CR1);
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spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
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spi_sh_wait_write_buffer_empty(ss);
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data = (unsigned char *)t->rx_buf;
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while (remain > 0) {
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if (remain >= SPI_SH_FIFO_SIZE) {
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ss->cr1 &= ~SPI_SH_RBF;
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spi_sh_set_bit(ss, SPI_SH_RBF, SPI_SH_CR4);
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ret = wait_event_interruptible_timeout(ss->wait,
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ss->cr1 & SPI_SH_RBF,
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SPI_SH_RECEIVE_TIMEOUT);
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if (ret == 0 &&
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spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
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printk(KERN_ERR "%s: timeout\n", __func__);
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return -ETIMEDOUT;
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}
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}
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cur_len = min(SPI_SH_FIFO_SIZE, remain);
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for (i = 0; i < cur_len; i++) {
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if (spi_sh_wait_receive_buffer(ss))
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break;
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data[i] = (unsigned char)spi_sh_read(ss, SPI_SH_RBR);
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}
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remain -= cur_len;
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data += cur_len;
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}
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/* deassert CS when SPI is receiving. */
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if (t->len > SPI_SH_MAX_BYTE) {
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clear_fifo(ss);
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spi_sh_write(ss, 1, SPI_SH_CR3);
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} else {
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spi_sh_write(ss, 0, SPI_SH_CR3);
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}
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return 0;
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}
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static void spi_sh_work(struct work_struct *work)
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{
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struct spi_sh_data *ss = container_of(work, struct spi_sh_data, ws);
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struct spi_message *mesg;
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struct spi_transfer *t;
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unsigned long flags;
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int ret;
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pr_debug("%s: enter\n", __func__);
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spin_lock_irqsave(&ss->lock, flags);
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while (!list_empty(&ss->queue)) {
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mesg = list_entry(ss->queue.next, struct spi_message, queue);
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list_del_init(&mesg->queue);
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spin_unlock_irqrestore(&ss->lock, flags);
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list_for_each_entry(t, &mesg->transfers, transfer_list) {
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pr_debug("tx_buf = %p, rx_buf = %p\n",
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t->tx_buf, t->rx_buf);
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pr_debug("len = %d, delay_usecs = %d\n",
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t->len, t->delay_usecs);
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if (t->tx_buf) {
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ret = spi_sh_send(ss, mesg, t);
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if (ret < 0)
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goto error;
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}
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if (t->rx_buf) {
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ret = spi_sh_receive(ss, mesg, t);
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if (ret < 0)
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goto error;
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}
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mesg->actual_length += t->len;
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}
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spin_lock_irqsave(&ss->lock, flags);
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mesg->status = 0;
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if (mesg->complete)
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mesg->complete(mesg->context);
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}
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clear_fifo(ss);
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spi_sh_set_bit(ss, SPI_SH_SSD, SPI_SH_CR1);
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udelay(100);
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spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
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SPI_SH_CR1);
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clear_fifo(ss);
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spin_unlock_irqrestore(&ss->lock, flags);
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return;
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error:
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mesg->status = ret;
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if (mesg->complete)
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mesg->complete(mesg->context);
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spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
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SPI_SH_CR1);
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clear_fifo(ss);
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}
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static int spi_sh_setup(struct spi_device *spi)
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{
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struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
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pr_debug("%s: enter\n", __func__);
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spi_sh_write(ss, 0xfe, SPI_SH_CR1); /* SPI sycle stop */
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spi_sh_write(ss, 0x00, SPI_SH_CR1); /* CR1 init */
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spi_sh_write(ss, 0x00, SPI_SH_CR3); /* CR3 init */
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clear_fifo(ss);
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/* 1/8 clock */
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spi_sh_write(ss, spi_sh_read(ss, SPI_SH_CR2) | 0x07, SPI_SH_CR2);
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udelay(10);
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return 0;
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}
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static int spi_sh_transfer(struct spi_device *spi, struct spi_message *mesg)
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{
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struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
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unsigned long flags;
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pr_debug("%s: enter\n", __func__);
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pr_debug("\tmode = %02x\n", spi->mode);
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spin_lock_irqsave(&ss->lock, flags);
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mesg->actual_length = 0;
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mesg->status = -EINPROGRESS;
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spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
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list_add_tail(&mesg->queue, &ss->queue);
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schedule_work(&ss->ws);
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spin_unlock_irqrestore(&ss->lock, flags);
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return 0;
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}
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static void spi_sh_cleanup(struct spi_device *spi)
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{
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struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
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pr_debug("%s: enter\n", __func__);
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spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
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SPI_SH_CR1);
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}
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static irqreturn_t spi_sh_irq(int irq, void *_ss)
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{
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struct spi_sh_data *ss = (struct spi_sh_data *)_ss;
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unsigned long cr1;
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cr1 = spi_sh_read(ss, SPI_SH_CR1);
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if (cr1 & SPI_SH_TBE)
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ss->cr1 |= SPI_SH_TBE;
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if (cr1 & SPI_SH_TBF)
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ss->cr1 |= SPI_SH_TBF;
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if (cr1 & SPI_SH_RBE)
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ss->cr1 |= SPI_SH_RBE;
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if (cr1 & SPI_SH_RBF)
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ss->cr1 |= SPI_SH_RBF;
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if (ss->cr1) {
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spi_sh_clear_bit(ss, ss->cr1, SPI_SH_CR4);
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wake_up(&ss->wait);
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}
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return IRQ_HANDLED;
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}
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static int spi_sh_remove(struct platform_device *pdev)
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{
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struct spi_sh_data *ss = platform_get_drvdata(pdev);
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spi_unregister_master(ss->master);
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flush_work(&ss->ws);
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free_irq(ss->irq, ss);
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return 0;
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}
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static int spi_sh_probe(struct platform_device *pdev)
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{
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struct resource *res;
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struct spi_master *master;
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struct spi_sh_data *ss;
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int ret, irq;
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/* get base addr */
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (unlikely(res == NULL)) {
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dev_err(&pdev->dev, "invalid resource\n");
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return -EINVAL;
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}
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irq = platform_get_irq(pdev, 0);
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if (irq < 0)
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return irq;
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master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
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if (master == NULL) {
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dev_err(&pdev->dev, "spi_alloc_master error.\n");
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return -ENOMEM;
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}
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ss = spi_master_get_devdata(master);
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platform_set_drvdata(pdev, ss);
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switch (res->flags & IORESOURCE_MEM_TYPE_MASK) {
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case IORESOURCE_MEM_8BIT:
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ss->width = 8;
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break;
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case IORESOURCE_MEM_32BIT:
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ss->width = 32;
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break;
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default:
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dev_err(&pdev->dev, "No support width\n");
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ret = -ENODEV;
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goto error1;
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}
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ss->irq = irq;
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ss->master = master;
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ss->addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
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if (ss->addr == NULL) {
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dev_err(&pdev->dev, "ioremap error.\n");
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ret = -ENOMEM;
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goto error1;
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}
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INIT_LIST_HEAD(&ss->queue);
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spin_lock_init(&ss->lock);
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INIT_WORK(&ss->ws, spi_sh_work);
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init_waitqueue_head(&ss->wait);
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ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);
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if (ret < 0) {
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dev_err(&pdev->dev, "request_irq error\n");
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goto error1;
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}
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master->num_chipselect = 2;
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master->bus_num = pdev->id;
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master->setup = spi_sh_setup;
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master->transfer = spi_sh_transfer;
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master->cleanup = spi_sh_cleanup;
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ret = spi_register_master(master);
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if (ret < 0) {
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printk(KERN_ERR "spi_register_master error.\n");
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goto error3;
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}
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return 0;
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error3:
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free_irq(irq, ss);
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error1:
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spi_master_put(master);
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return ret;
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}
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static struct platform_driver spi_sh_driver = {
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.probe = spi_sh_probe,
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.remove = spi_sh_remove,
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.driver = {
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.name = "sh_spi",
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},
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};
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module_platform_driver(spi_sh_driver);
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MODULE_DESCRIPTION("SH SPI bus driver");
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MODULE_LICENSE("GPL v2");
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MODULE_AUTHOR("Yoshihiro Shimoda");
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MODULE_ALIAS("platform:sh_spi");
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