diff options
Diffstat (limited to 'drivers/spi/spi-rspi.c')
| -rw-r--r-- | drivers/spi/spi-rspi.c | 521 |
1 files changed, 521 insertions, 0 deletions
diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c new file mode 100644 index 000000000000..354f170eab95 --- /dev/null +++ b/drivers/spi/spi-rspi.c @@ -0,0 +1,521 @@ +/* + * SH RSPI driver + * + * Copyright (C) 2012 Renesas Solutions Corp. + * + * Based on spi-sh.c: + * Copyright (C) 2011 Renesas Solutions Corp. + * + * 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/list.h> +#include <linux/workqueue.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/clk.h> +#include <linux/spi/spi.h> + +#define RSPI_SPCR 0x00 +#define RSPI_SSLP 0x01 +#define RSPI_SPPCR 0x02 +#define RSPI_SPSR 0x03 +#define RSPI_SPDR 0x04 +#define RSPI_SPSCR 0x08 +#define RSPI_SPSSR 0x09 +#define RSPI_SPBR 0x0a +#define RSPI_SPDCR 0x0b +#define RSPI_SPCKD 0x0c +#define RSPI_SSLND 0x0d +#define RSPI_SPND 0x0e +#define RSPI_SPCR2 0x0f +#define RSPI_SPCMD0 0x10 +#define RSPI_SPCMD1 0x12 +#define RSPI_SPCMD2 0x14 +#define RSPI_SPCMD3 0x16 +#define RSPI_SPCMD4 0x18 +#define RSPI_SPCMD5 0x1a +#define RSPI_SPCMD6 0x1c +#define RSPI_SPCMD7 0x1e + +/* SPCR */ +#define SPCR_SPRIE 0x80 +#define SPCR_SPE 0x40 +#define SPCR_SPTIE 0x20 +#define SPCR_SPEIE 0x10 +#define SPCR_MSTR 0x08 +#define SPCR_MODFEN 0x04 +#define SPCR_TXMD 0x02 +#define SPCR_SPMS 0x01 + +/* SSLP */ +#define SSLP_SSL1P 0x02 +#define SSLP_SSL0P 0x01 + +/* SPPCR */ +#define SPPCR_MOIFE 0x20 +#define SPPCR_MOIFV 0x10 +#define SPPCR_SPOM 0x04 +#define SPPCR_SPLP2 0x02 +#define SPPCR_SPLP 0x01 + +/* SPSR */ +#define SPSR_SPRF 0x80 +#define SPSR_SPTEF 0x20 +#define SPSR_PERF 0x08 +#define SPSR_MODF 0x04 +#define SPSR_IDLNF 0x02 +#define SPSR_OVRF 0x01 + +/* SPSCR */ +#define SPSCR_SPSLN_MASK 0x07 + +/* SPSSR */ +#define SPSSR_SPECM_MASK 0x70 +#define SPSSR_SPCP_MASK 0x07 + +/* SPDCR */ +#define SPDCR_SPLW 0x20 +#define SPDCR_SPRDTD 0x10 +#define SPDCR_SLSEL1 0x08 +#define SPDCR_SLSEL0 0x04 +#define SPDCR_SLSEL_MASK 0x0c +#define SPDCR_SPFC1 0x02 +#define SPDCR_SPFC0 0x01 + +/* SPCKD */ +#define SPCKD_SCKDL_MASK 0x07 + +/* SSLND */ +#define SSLND_SLNDL_MASK 0x07 + +/* SPND */ +#define SPND_SPNDL_MASK 0x07 + +/* SPCR2 */ +#define SPCR2_PTE 0x08 +#define SPCR2_SPIE 0x04 +#define SPCR2_SPOE 0x02 +#define SPCR2_SPPE 0x01 + +/* SPCMDn */ +#define SPCMD_SCKDEN 0x8000 +#define SPCMD_SLNDEN 0x4000 +#define SPCMD_SPNDEN 0x2000 +#define SPCMD_LSBF 0x1000 +#define SPCMD_SPB_MASK 0x0f00 +#define SPCMD_SPB_8_TO_16(bit) (((bit - 1) << 8) & SPCMD_SPB_MASK) +#define SPCMD_SPB_20BIT 0x0000 +#define SPCMD_SPB_24BIT 0x0100 +#define SPCMD_SPB_32BIT 0x0200 +#define SPCMD_SSLKP 0x0080 +#define SPCMD_SSLA_MASK 0x0030 +#define SPCMD_BRDV_MASK 0x000c +#define SPCMD_CPOL 0x0002 +#define SPCMD_CPHA 0x0001 + +struct rspi_data { + void __iomem *addr; + u32 max_speed_hz; + struct spi_master *master; + struct list_head queue; + struct work_struct ws; + wait_queue_head_t wait; + spinlock_t lock; + struct clk *clk; + unsigned char spsr; +}; + +static void rspi_write8(struct rspi_data *rspi, u8 data, u16 offset) +{ + iowrite8(data, rspi->addr + offset); +} + +static void rspi_write16(struct rspi_data *rspi, u16 data, u16 offset) +{ + iowrite16(data, rspi->addr + offset); +} + +static u8 rspi_read8(struct rspi_data *rspi, u16 offset) +{ + return ioread8(rspi->addr + offset); +} + +static u16 rspi_read16(struct rspi_data *rspi, u16 offset) +{ + return ioread16(rspi->addr + offset); +} + +static unsigned char rspi_calc_spbr(struct rspi_data *rspi) +{ + int tmp; + unsigned char spbr; + + tmp = clk_get_rate(rspi->clk) / (2 * rspi->max_speed_hz) - 1; + spbr = clamp(tmp, 0, 255); + + return spbr; +} + +static void rspi_enable_irq(struct rspi_data *rspi, u8 enable) +{ + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR); +} + +static void rspi_disable_irq(struct rspi_data *rspi, u8 disable) +{ + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR); +} + +static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask, + u8 enable_bit) +{ + int ret; + + rspi->spsr = rspi_read8(rspi, RSPI_SPSR); + rspi_enable_irq(rspi, enable_bit); + ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ); + if (ret == 0 && !(rspi->spsr & wait_mask)) + return -ETIMEDOUT; + + return 0; +} + +static void rspi_assert_ssl(struct rspi_data *rspi) +{ + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR); +} + +static void rspi_negate_ssl(struct rspi_data *rspi) +{ + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR); +} + +static int rspi_set_config_register(struct rspi_data *rspi, int access_size) +{ + /* Sets output mode(CMOS) and MOSI signal(from previous transfer) */ + rspi_write8(rspi, 0x00, RSPI_SPPCR); + + /* Sets transfer bit rate */ + rspi_write8(rspi, rspi_calc_spbr(rspi), RSPI_SPBR); + + /* Sets number of frames to be used: 1 frame */ + rspi_write8(rspi, 0x00, RSPI_SPDCR); + + /* Sets RSPCK, SSL, next-access delay value */ + rspi_write8(rspi, 0x00, RSPI_SPCKD); + rspi_write8(rspi, 0x00, RSPI_SSLND); + rspi_write8(rspi, 0x00, RSPI_SPND); + + /* Sets parity, interrupt mask */ + rspi_write8(rspi, 0x00, RSPI_SPCR2); + + /* Sets SPCMD */ + rspi_write16(rspi, SPCMD_SPB_8_TO_16(access_size) | SPCMD_SSLKP, + RSPI_SPCMD0); + + /* Sets RSPI mode */ + rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR); + + return 0; +} + +static int rspi_send_pio(struct rspi_data *rspi, struct spi_message *mesg, + struct spi_transfer *t) +{ + int remain = t->len; + u8 *data; + + data = (u8 *)t->tx_buf; + while (remain > 0) { + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD, + RSPI_SPCR); + + if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) { + dev_err(&rspi->master->dev, + "%s: tx empty timeout\n", __func__); + return -ETIMEDOUT; + } + + rspi_write16(rspi, *data, RSPI_SPDR); + data++; + remain--; + } + + /* Waiting for the last transmition */ + rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE); + + return 0; +} + +static int rspi_receive_pio(struct rspi_data *rspi, struct spi_message *mesg, + struct spi_transfer *t) +{ + int remain = t->len; + u8 *data; + unsigned char spsr; + + spsr = rspi_read8(rspi, RSPI_SPSR); + if (spsr & SPSR_SPRF) + rspi_read16(rspi, RSPI_SPDR); /* dummy read */ + if (spsr & SPSR_OVRF) + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF, + RSPI_SPCR); + + data = (u8 *)t->rx_buf; + while (remain > 0) { + rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD, + RSPI_SPCR); + + if (rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE) < 0) { + dev_err(&rspi->master->dev, + "%s: tx empty timeout\n", __func__); + return -ETIMEDOUT; + } + /* dummy write for generate clock */ + rspi_write16(rspi, 0x00, RSPI_SPDR); + + if (rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE) < 0) { + dev_err(&rspi->master->dev, + "%s: receive timeout\n", __func__); + return -ETIMEDOUT; + } + /* SPDR allows 16 or 32-bit access only */ + *data = (u8)rspi_read16(rspi, RSPI_SPDR); + + data++; + remain--; + } + + return 0; +} + +static void rspi_work(struct work_struct *work) +{ + struct rspi_data *rspi = container_of(work, struct rspi_data, ws); + struct spi_message *mesg; + struct spi_transfer *t; + unsigned long flags; + int ret; + + spin_lock_irqsave(&rspi->lock, flags); + while (!list_empty(&rspi->queue)) { + mesg = list_entry(rspi->queue.next, struct spi_message, queue); + list_del_init(&mesg->queue); + spin_unlock_irqrestore(&rspi->lock, flags); + + rspi_assert_ssl(rspi); + + list_for_each_entry(t, &mesg->transfers, transfer_list) { + if (t->tx_buf) { + ret = rspi_send_pio(rspi, mesg, t); + if (ret < 0) + goto error; + } + if (t->rx_buf) { + ret = rspi_receive_pio(rspi, mesg, t); + if (ret < 0) + goto error; + } + mesg->actual_length += t->len; + } + rspi_negate_ssl(rspi); + + mesg->status = 0; + mesg->complete(mesg->context); + + spin_lock_irqsave(&rspi->lock, flags); + } + + return; + +error: + mesg->status = ret; + mesg->complete(mesg->context); +} + +static int rspi_setup(struct spi_device *spi) +{ + struct rspi_data *rspi = spi_master_get_devdata(spi->master); + + if (!spi->bits_per_word) + spi->bits_per_word = 8; + rspi->max_speed_hz = spi->max_speed_hz; + + rspi_set_config_register(rspi, 8); + + return 0; +} + +static int rspi_transfer(struct spi_device *spi, struct spi_message *mesg) +{ + struct rspi_data *rspi = spi_master_get_devdata(spi->master); + unsigned long flags; + + mesg->actual_length = 0; + mesg->status = -EINPROGRESS; + + spin_lock_irqsave(&rspi->lock, flags); + list_add_tail(&mesg->queue, &rspi->queue); + schedule_work(&rspi->ws); + spin_unlock_irqrestore(&rspi->lock, flags); + + return 0; +} + +static void rspi_cleanup(struct spi_device *spi) +{ +} + +static irqreturn_t rspi_irq(int irq, void *_sr) +{ + struct rspi_data *rspi = (struct rspi_data *)_sr; + unsigned long spsr; + irqreturn_t ret = IRQ_NONE; + unsigned char disable_irq = 0; + + rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR); + if (spsr & SPSR_SPRF) + disable_irq |= SPCR_SPRIE; + if (spsr & SPSR_SPTEF) + disable_irq |= SPCR_SPTIE; + + if (disable_irq) { + ret = IRQ_HANDLED; + rspi_disable_irq(rspi, disable_irq); + wake_up(&rspi->wait); + } + + return ret; +} + +static int __devexit rspi_remove(struct platform_device *pdev) +{ + struct rspi_data *rspi = dev_get_drvdata(&pdev->dev); + + spi_unregister_master(rspi->master); + free_irq(platform_get_irq(pdev, 0), rspi); + clk_put(rspi->clk); + iounmap(rspi->addr); + spi_master_put(rspi->master); + + return 0; +} + +static int __devinit rspi_probe(struct platform_device *pdev) +{ + struct resource *res; + struct spi_master *master; + struct rspi_data *rspi; + int ret, irq; + char clk_name[16]; + + /* 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 rspi_data)); + if (master == NULL) { + dev_err(&pdev->dev, "spi_alloc_master error.\n"); + return -ENOMEM; + } + + rspi = spi_master_get_devdata(master); + dev_set_drvdata(&pdev->dev, rspi); + + rspi->master = master; + rspi->addr = ioremap(res->start, resource_size(res)); + if (rspi->addr == NULL) { + dev_err(&pdev->dev, "ioremap error.\n"); + ret = -ENOMEM; + goto error1; + } + + snprintf(clk_name, sizeof(clk_name), "rspi%d", pdev->id); + rspi->clk = clk_get(&pdev->dev, clk_name); + if (IS_ERR(rspi->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + ret = PTR_ERR(rspi->clk); + goto error2; + } + clk_enable(rspi->clk); + + INIT_LIST_HEAD(&rspi->queue); + spin_lock_init(&rspi->lock); + INIT_WORK(&rspi->ws, rspi_work); + init_waitqueue_head(&rspi->wait); + + master->num_chipselect = 2; + master->bus_num = pdev->id; + master->setup = rspi_setup; + master->transfer = rspi_transfer; + master->cleanup = rspi_cleanup; + + ret = request_irq(irq, rspi_irq, 0, dev_name(&pdev->dev), rspi); + if (ret < 0) { + dev_err(&pdev->dev, "request_irq error\n"); + goto error3; + } + + ret = spi_register_master(master); + if (ret < 0) { + dev_err(&pdev->dev, "spi_register_master error.\n"); + goto error4; + } + + dev_info(&pdev->dev, "probed\n"); + + return 0; + +error4: + free_irq(irq, rspi); +error3: + clk_put(rspi->clk); +error2: + iounmap(rspi->addr); +error1: + spi_master_put(master); + + return ret; +} + +static struct platform_driver rspi_driver = { + .probe = rspi_probe, + .remove = __devexit_p(rspi_remove), + .driver = { + .name = "rspi", + .owner = THIS_MODULE, + }, +}; +module_platform_driver(rspi_driver); + +MODULE_DESCRIPTION("Renesas RSPI bus driver"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Yoshihiro Shimoda"); +MODULE_ALIAS("platform:rspi"); |