diff options
Diffstat (limited to 'drivers/spi/spi-sh.c')
| -rw-r--r-- | drivers/spi/spi-sh.c | 543 |
1 files changed, 543 insertions, 0 deletions
diff --git a/drivers/spi/spi-sh.c b/drivers/spi/spi-sh.c new file mode 100644 index 0000000..9eedd71 --- /dev/null +++ b/drivers/spi/spi-sh.c @@ -0,0 +1,543 @@ +/* + * SH SPI bus driver + * + * Copyright (C) 2011 Renesas Solutions Corp. + * + * Based on pxa2xx_spi.c: + * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs + * + * 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. + * + * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + */ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/errno.h> +#include <linux/timer.h> +#include <linux/delay.h> +#include <linux/list.h> +#include <linux/workqueue.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/spi/spi.h> + +#define SPI_SH_TBR 0x00 +#define SPI_SH_RBR 0x00 +#define SPI_SH_CR1 0x08 +#define SPI_SH_CR2 0x10 +#define SPI_SH_CR3 0x18 +#define SPI_SH_CR4 0x20 +#define SPI_SH_CR5 0x28 + +/* CR1 */ +#define SPI_SH_TBE 0x80 +#define SPI_SH_TBF 0x40 +#define SPI_SH_RBE 0x20 +#define SPI_SH_RBF 0x10 +#define SPI_SH_PFONRD 0x08 +#define SPI_SH_SSDB 0x04 +#define SPI_SH_SSD 0x02 +#define SPI_SH_SSA 0x01 + +/* CR2 */ +#define SPI_SH_RSTF 0x80 +#define SPI_SH_LOOPBK 0x40 +#define SPI_SH_CPOL 0x20 +#define SPI_SH_CPHA 0x10 +#define SPI_SH_L1M0 0x08 + +/* CR3 */ +#define SPI_SH_MAX_BYTE 0xFF + +/* CR4 */ +#define SPI_SH_TBEI 0x80 +#define SPI_SH_TBFI 0x40 +#define SPI_SH_RBEI 0x20 +#define SPI_SH_RBFI 0x10 +#define SPI_SH_WPABRT 0x04 +#define SPI_SH_SSS 0x01 + +/* CR8 */ +#define SPI_SH_P1L0 0x80 +#define SPI_SH_PP1L0 0x40 +#define SPI_SH_MUXI 0x20 +#define SPI_SH_MUXIRQ 0x10 + +#define SPI_SH_FIFO_SIZE 32 +#define SPI_SH_SEND_TIMEOUT (3 * HZ) +#define SPI_SH_RECEIVE_TIMEOUT (HZ >> 3) + +#undef DEBUG + +struct spi_sh_data { + void __iomem *addr; + int irq; + struct spi_master *master; + struct list_head queue; + struct workqueue_struct *workqueue; + struct work_struct ws; + unsigned long cr1; + wait_queue_head_t wait; + spinlock_t lock; +}; + +static void spi_sh_write(struct spi_sh_data *ss, unsigned long data, + unsigned long offset) +{ + writel(data, ss->addr + offset); +} + +static unsigned long spi_sh_read(struct spi_sh_data *ss, unsigned long offset) +{ + return readl(ss->addr + offset); +} + +static void spi_sh_set_bit(struct spi_sh_data *ss, unsigned long val, + unsigned long offset) +{ + unsigned long tmp; + + tmp = spi_sh_read(ss, offset); + tmp |= val; + spi_sh_write(ss, tmp, offset); +} + +static void spi_sh_clear_bit(struct spi_sh_data *ss, unsigned long val, + unsigned long offset) +{ + unsigned long tmp; + + tmp = spi_sh_read(ss, offset); + tmp &= ~val; + spi_sh_write(ss, tmp, offset); +} + +static void clear_fifo(struct spi_sh_data *ss) +{ + spi_sh_set_bit(ss, SPI_SH_RSTF, SPI_SH_CR2); + spi_sh_clear_bit(ss, SPI_SH_RSTF, SPI_SH_CR2); +} + +static int spi_sh_wait_receive_buffer(struct spi_sh_data *ss) +{ + int timeout = 100000; + + while (spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) { + udelay(10); + if (timeout-- < 0) + return -ETIMEDOUT; + } + return 0; +} + +static int spi_sh_wait_write_buffer_empty(struct spi_sh_data *ss) +{ + int timeout = 100000; + + while (!(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBE)) { + udelay(10); + if (timeout-- < 0) + return -ETIMEDOUT; + } + return 0; +} + +static int spi_sh_send(struct spi_sh_data *ss, struct spi_message *mesg, + struct spi_transfer *t) +{ + int i, retval = 0; + int remain = t->len; + int cur_len; + unsigned char *data; + unsigned long tmp; + long ret; + + if (t->len) + spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1); + + data = (unsigned char *)t->tx_buf; + while (remain > 0) { + cur_len = min(SPI_SH_FIFO_SIZE, remain); + for (i = 0; i < cur_len && + !(spi_sh_read(ss, SPI_SH_CR4) & + SPI_SH_WPABRT) && + !(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBF); + i++) + spi_sh_write(ss, (unsigned long)data[i], SPI_SH_TBR); + + if (spi_sh_read(ss, SPI_SH_CR4) & SPI_SH_WPABRT) { + /* Abort SPI operation */ + spi_sh_set_bit(ss, SPI_SH_WPABRT, SPI_SH_CR4); + retval = -EIO; + break; + } + + cur_len = i; + + remain -= cur_len; + data += cur_len; + + if (remain > 0) { + ss->cr1 &= ~SPI_SH_TBE; + spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4); + ret = wait_event_interruptible_timeout(ss->wait, + ss->cr1 & SPI_SH_TBE, + SPI_SH_SEND_TIMEOUT); + if (ret == 0 && !(ss->cr1 & SPI_SH_TBE)) { + printk(KERN_ERR "%s: timeout\n", __func__); + return -ETIMEDOUT; + } + } + } + + if (list_is_last(&t->transfer_list, &mesg->transfers)) { + tmp = spi_sh_read(ss, SPI_SH_CR1); + tmp = tmp & ~(SPI_SH_SSD | SPI_SH_SSDB); + spi_sh_write(ss, tmp, SPI_SH_CR1); + spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1); + + ss->cr1 &= ~SPI_SH_TBE; + spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4); + ret = wait_event_interruptible_timeout(ss->wait, + ss->cr1 & SPI_SH_TBE, + SPI_SH_SEND_TIMEOUT); + if (ret == 0 && (ss->cr1 & SPI_SH_TBE)) { + printk(KERN_ERR "%s: timeout\n", __func__); + return -ETIMEDOUT; + } + } + + return retval; +} + +static int spi_sh_receive(struct spi_sh_data *ss, struct spi_message *mesg, + struct spi_transfer *t) +{ + int i; + int remain = t->len; + int cur_len; + unsigned char *data; + unsigned long tmp; + long ret; + + if (t->len > SPI_SH_MAX_BYTE) + spi_sh_write(ss, SPI_SH_MAX_BYTE, SPI_SH_CR3); + else + spi_sh_write(ss, t->len, SPI_SH_CR3); + + tmp = spi_sh_read(ss, SPI_SH_CR1); + tmp = tmp & ~(SPI_SH_SSD | SPI_SH_SSDB); + spi_sh_write(ss, tmp, SPI_SH_CR1); + spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1); + + spi_sh_wait_write_buffer_empty(ss); + + data = (unsigned char *)t->rx_buf; + while (remain > 0) { + if (remain >= SPI_SH_FIFO_SIZE) { + ss->cr1 &= ~SPI_SH_RBF; + spi_sh_set_bit(ss, SPI_SH_RBF, SPI_SH_CR4); + ret = wait_event_interruptible_timeout(ss->wait, + ss->cr1 & SPI_SH_RBF, + SPI_SH_RECEIVE_TIMEOUT); + if (ret == 0 && + spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) { + printk(KERN_ERR "%s: timeout\n", __func__); + return -ETIMEDOUT; + } + } + + cur_len = min(SPI_SH_FIFO_SIZE, remain); + for (i = 0; i < cur_len; i++) { + if (spi_sh_wait_receive_buffer(ss)) + break; + data[i] = (unsigned char)spi_sh_read(ss, SPI_SH_RBR); + } + + remain -= cur_len; + data += cur_len; + } + + /* deassert CS when SPI is receiving. */ + if (t->len > SPI_SH_MAX_BYTE) { + clear_fifo(ss); + spi_sh_write(ss, 1, SPI_SH_CR3); + } else { + spi_sh_write(ss, 0, SPI_SH_CR3); + } + + return 0; +} + +static void spi_sh_work(struct work_struct *work) +{ + struct spi_sh_data *ss = container_of(work, struct spi_sh_data, ws); + struct spi_message *mesg; + struct spi_transfer *t; + unsigned long flags; + int ret; + + pr_debug("%s: enter\n", __func__); + + spin_lock_irqsave(&ss->lock, flags); + while (!list_empty(&ss->queue)) { + mesg = list_entry(ss->queue.next, struct spi_message, queue); + list_del_init(&mesg->queue); + + spin_unlock_irqrestore(&ss->lock, flags); + list_for_each_entry(t, &mesg->transfers, transfer_list) { + pr_debug("tx_buf = %p, rx_buf = %p\n", + t->tx_buf, t->rx_buf); + pr_debug("len = %d, delay_usecs = %d\n", + t->len, t->delay_usecs); + + if (t->tx_buf) { + ret = spi_sh_send(ss, mesg, t); + if (ret < 0) + goto error; + } + if (t->rx_buf) { + ret = spi_sh_receive(ss, mesg, t); + if (ret < 0) + goto error; + } + mesg->actual_length += t->len; + } + spin_lock_irqsave(&ss->lock, flags); + + mesg->status = 0; + mesg->complete(mesg->context); + } + + clear_fifo(ss); + spi_sh_set_bit(ss, SPI_SH_SSD, SPI_SH_CR1); + udelay(100); + + spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD, + SPI_SH_CR1); + + clear_fifo(ss); + + spin_unlock_irqrestore(&ss->lock, flags); + + return; + + error: + mesg->status = ret; + mesg->complete(mesg->context); + + spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD, + SPI_SH_CR1); + clear_fifo(ss); + +} + +static int spi_sh_setup(struct spi_device *spi) +{ + struct spi_sh_data *ss = spi_master_get_devdata(spi->master); + + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + pr_debug("%s: enter\n", __func__); + + spi_sh_write(ss, 0xfe, SPI_SH_CR1); /* SPI sycle stop */ + spi_sh_write(ss, 0x00, SPI_SH_CR1); /* CR1 init */ + spi_sh_write(ss, 0x00, SPI_SH_CR3); /* CR3 init */ + + clear_fifo(ss); + + /* 1/8 clock */ + spi_sh_write(ss, spi_sh_read(ss, SPI_SH_CR2) | 0x07, SPI_SH_CR2); + udelay(10); + + return 0; +} + +static int spi_sh_transfer(struct spi_device *spi, struct spi_message *mesg) +{ + struct spi_sh_data *ss = spi_master_get_devdata(spi->master); + unsigned long flags; + + pr_debug("%s: enter\n", __func__); + pr_debug("\tmode = %02x\n", spi->mode); + + spin_lock_irqsave(&ss->lock, flags); + + mesg->actual_length = 0; + mesg->status = -EINPROGRESS; + + spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1); + + list_add_tail(&mesg->queue, &ss->queue); + queue_work(ss->workqueue, &ss->ws); + + spin_unlock_irqrestore(&ss->lock, flags); + + return 0; +} + +static void spi_sh_cleanup(struct spi_device *spi) +{ + struct spi_sh_data *ss = spi_master_get_devdata(spi->master); + + pr_debug("%s: enter\n", __func__); + + spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD, + SPI_SH_CR1); +} + +static irqreturn_t spi_sh_irq(int irq, void *_ss) +{ + struct spi_sh_data *ss = (struct spi_sh_data *)_ss; + unsigned long cr1; + + cr1 = spi_sh_read(ss, SPI_SH_CR1); + if (cr1 & SPI_SH_TBE) + ss->cr1 |= SPI_SH_TBE; + if (cr1 & SPI_SH_TBF) + ss->cr1 |= SPI_SH_TBF; + if (cr1 & SPI_SH_RBE) + ss->cr1 |= SPI_SH_RBE; + if (cr1 & SPI_SH_RBF) + ss->cr1 |= SPI_SH_RBF; + + if (ss->cr1) { + spi_sh_clear_bit(ss, ss->cr1, SPI_SH_CR4); + wake_up(&ss->wait); + } + + return IRQ_HANDLED; +} + +static int __devexit spi_sh_remove(struct platform_device *pdev) +{ + struct spi_sh_data *ss = dev_get_drvdata(&pdev->dev); + + spi_unregister_master(ss->master); + destroy_workqueue(ss->workqueue); + free_irq(ss->irq, ss); + iounmap(ss->addr); + + return 0; +} + +static int __devinit spi_sh_probe(struct platform_device *pdev) +{ + struct resource *res; + struct spi_master *master; + struct spi_sh_data *ss; + int ret, irq; + + /* get base addr */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(res == NULL)) { + dev_err(&pdev->dev, "invalid resource\n"); + return -EINVAL; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + dev_err(&pdev->dev, "platform_get_irq error\n"); + return -ENODEV; + } + + master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data)); + if (master == NULL) { + dev_err(&pdev->dev, "spi_alloc_master error.\n"); + return -ENOMEM; + } + + ss = spi_master_get_devdata(master); + dev_set_drvdata(&pdev->dev, ss); + + ss->irq = irq; + ss->master = master; + ss->addr = ioremap(res->start, resource_size(res)); + if (ss->addr == NULL) { + dev_err(&pdev->dev, "ioremap error.\n"); + ret = -ENOMEM; + goto error1; + } + INIT_LIST_HEAD(&ss->queue); + spin_lock_init(&ss->lock); + INIT_WORK(&ss->ws, spi_sh_work); + init_waitqueue_head(&ss->wait); + ss->workqueue = create_singlethread_workqueue( + dev_name(master->dev.parent)); + if (ss->workqueue == NULL) { + dev_err(&pdev->dev, "create workqueue error\n"); + ret = -EBUSY; + goto error2; + } + + ret = request_irq(irq, spi_sh_irq, IRQF_DISABLED, "spi_sh", ss); + if (ret < 0) { + dev_err(&pdev->dev, "request_irq error\n"); + goto error3; + } + + master->num_chipselect = 2; + master->bus_num = pdev->id; + master->setup = spi_sh_setup; + master->transfer = spi_sh_transfer; + master->cleanup = spi_sh_cleanup; + + ret = spi_register_master(master); + if (ret < 0) { + printk(KERN_ERR "spi_register_master error.\n"); + goto error4; + } + + return 0; + + error4: + free_irq(irq, ss); + error3: + destroy_workqueue(ss->workqueue); + error2: + iounmap(ss->addr); + error1: + spi_master_put(master); + + return ret; +} + +static struct platform_driver spi_sh_driver = { + .probe = spi_sh_probe, + .remove = __devexit_p(spi_sh_remove), + .driver = { + .name = "sh_spi", + .owner = THIS_MODULE, + }, +}; + +static int __init spi_sh_init(void) +{ + return platform_driver_register(&spi_sh_driver); +} +module_init(spi_sh_init); + +static void __exit spi_sh_exit(void) +{ + platform_driver_unregister(&spi_sh_driver); +} +module_exit(spi_sh_exit); + +MODULE_DESCRIPTION("SH SPI bus driver"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Yoshihiro Shimoda"); +MODULE_ALIAS("platform:sh_spi"); |
