/* * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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; /* for dmaengine */ struct dma_chan *chan_tx; struct dma_chan *chan_rx; int irq; unsigned dma_width_16bit:1; unsigned dma_callbacked:1; }; 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 void rspi_dma_complete(void *arg) { struct rspi_data *rspi = arg; rspi->dma_callbacked = 1; wake_up_interruptible(&rspi->wait); } static int rspi_dma_map_sg(struct scatterlist *sg, void *buf, unsigned len, struct dma_chan *chan, enum dma_transfer_direction dir) { sg_init_table(sg, 1); sg_set_buf(sg, buf, len); sg_dma_len(sg) = len; return dma_map_sg(chan->device->dev, sg, 1, dir); } static void rspi_dma_unmap_sg(struct scatterlist *sg, struct dma_chan *chan, enum dma_transfer_direction dir) { dma_unmap_sg(chan->device->dev, sg, 1, dir); } static void rspi_memory_to_8bit(void *buf, const void *data, unsigned len) { u16 *dst = buf; const u8 *src = data; while (len) { *dst++ = (u16)(*src++); len--; } } static void rspi_memory_from_8bit(void *buf, const void *data, unsigned len) { u8 *dst = buf; const u16 *src = data; while (len) { *dst++ = (u8)*src++; len--; } } static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t) { struct scatterlist sg; void *buf = NULL; struct dma_async_tx_descriptor *desc; unsigned len; int ret = 0; if (rspi->dma_width_16bit) { /* * If DMAC bus width is 16-bit, the driver allocates a dummy * buffer. And, the driver converts original data into the * DMAC data as the following format: * original data: 1st byte, 2nd byte ... * DMAC data: 1st byte, dummy, 2nd byte, dummy ... */ len = t->len * 2; buf = kmalloc(len, GFP_KERNEL); if (!buf) return -ENOMEM; rspi_memory_to_8bit(buf, t->tx_buf, t->len); } else { len = t->len; buf = (void *)t->tx_buf; } if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE)) { ret = -EFAULT; goto end_nomap; } desc = dmaengine_prep_slave_sg(rspi->chan_tx, &sg, 1, DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { ret = -EIO; goto end; } /* * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be * called. So, this driver disables the IRQ while DMA transfer. */ disable_irq(rspi->irq); rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_TXMD, RSPI_SPCR); rspi_enable_irq(rspi, SPCR_SPTIE); rspi->dma_callbacked = 0; desc->callback = rspi_dma_complete; desc->callback_param = rspi; dmaengine_submit(desc); dma_async_issue_pending(rspi->chan_tx); ret = wait_event_interruptible_timeout(rspi->wait, rspi->dma_callbacked, HZ); if (ret > 0 && rspi->dma_callbacked) ret = 0; else if (!ret) ret = -ETIMEDOUT; rspi_disable_irq(rspi, SPCR_SPTIE); enable_irq(rspi->irq); end: rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE); end_nomap: if (rspi->dma_width_16bit) kfree(buf); return ret; } static void rspi_receive_init(struct rspi_data *rspi) { 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); } static int rspi_receive_pio(struct rspi_data *rspi, struct spi_message *mesg, struct spi_transfer *t) { int remain = t->len; u8 *data; rspi_receive_init(rspi); 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 int rspi_receive_dma(struct rspi_data *rspi, struct spi_transfer *t) { struct scatterlist sg, sg_dummy; void *dummy = NULL, *rx_buf = NULL; struct dma_async_tx_descriptor *desc, *desc_dummy; unsigned len; int ret = 0; if (rspi->dma_width_16bit) { /* * If DMAC bus width is 16-bit, the driver allocates a dummy * buffer. And, finally the driver converts the DMAC data into * actual data as the following format: * DMAC data: 1st byte, dummy, 2nd byte, dummy ... * actual data: 1st byte, 2nd byte ... */ len = t->len * 2; rx_buf = kmalloc(len, GFP_KERNEL); if (!rx_buf) return -ENOMEM; } else { len = t->len; rx_buf = t->rx_buf; } /* prepare dummy transfer to generate SPI clocks */ dummy = kzalloc(len, GFP_KERNEL); if (!dummy) { ret = -ENOMEM; goto end_nomap; } if (!rspi_dma_map_sg(&sg_dummy, dummy, len, rspi->chan_tx, DMA_TO_DEVICE)) { ret = -EFAULT; goto end_nomap; } desc_dummy = dmaengine_prep_slave_sg(rspi->chan_tx, &sg_dummy, 1, DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc_dummy) { ret = -EIO; goto end_dummy_mapped; } /* prepare receive transfer */ if (!rspi_dma_map_sg(&sg, rx_buf, len, rspi->chan_rx, DMA_FROM_DEVICE)) { ret = -EFAULT; goto end_dummy_mapped; } desc = dmaengine_prep_slave_sg(rspi->chan_rx, &sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { ret = -EIO; goto end; } rspi_receive_init(rspi); /* * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be * called. So, this driver disables the IRQ while DMA transfer. */ disable_irq(rspi->irq); rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_TXMD, RSPI_SPCR); rspi_enable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE); rspi->dma_callbacked = 0; desc->callback = rspi_dma_complete; desc->callback_param = rspi; dmaengine_submit(desc); dma_async_issue_pending(rspi->chan_rx); desc_dummy->callback = NULL; /* No callback */ dmaengine_submit(desc_dummy); dma_async_issue_pending(rspi->chan_tx); ret = wait_event_interruptible_timeout(rspi->wait, rspi->dma_callbacked, HZ); if (ret > 0 && rspi->dma_callbacked) ret = 0; else if (!ret) ret = -ETIMEDOUT; rspi_disable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE); enable_irq(rspi->irq); end: rspi_dma_unmap_sg(&sg, rspi->chan_rx, DMA_FROM_DEVICE); end_dummy_mapped: rspi_dma_unmap_sg(&sg_dummy, rspi->chan_tx, DMA_TO_DEVICE); end_nomap: if (rspi->dma_width_16bit) { if (!ret) rspi_memory_from_8bit(t->rx_buf, rx_buf, t->len); kfree(rx_buf); } kfree(dummy); return ret; } static int rspi_is_dma(struct rspi_data *rspi, struct spi_transfer *t) { if (t->tx_buf && rspi->chan_tx) return 1; /* If the module receives data by DMAC, it also needs TX DMAC */ if (t->rx_buf && rspi->chan_tx && rspi->chan_rx) return 1; 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) { if (rspi_is_dma(rspi, t)) ret = rspi_send_dma(rspi, t); else ret = rspi_send_pio(rspi, mesg, t); if (ret < 0) goto error; } if (t->rx_buf) { if (rspi_is_dma(rspi, t)) ret = rspi_receive_dma(rspi, t); else 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 rspi_request_dma(struct rspi_data *rspi, struct platform_device *pdev) { struct rspi_plat_data *rspi_pd = pdev->dev.platform_data; dma_cap_mask_t mask; struct dma_slave_config cfg; int ret; if (!rspi_pd) return 0; /* The driver assumes no error. */ rspi->dma_width_16bit = rspi_pd->dma_width_16bit; /* If the module receives data by DMAC, it also needs TX DMAC */ if (rspi_pd->dma_rx_id && rspi_pd->dma_tx_id) { dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); rspi->chan_rx = dma_request_channel(mask, shdma_chan_filter, (void *)rspi_pd->dma_rx_id); if (rspi->chan_rx) { cfg.slave_id = rspi_pd->dma_rx_id; cfg.direction = DMA_DEV_TO_MEM; ret = dmaengine_slave_config(rspi->chan_rx, &cfg); if (!ret) dev_info(&pdev->dev, "Use DMA when rx.\n"); else return ret; } } if (rspi_pd->dma_tx_id) { dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); rspi->chan_tx = dma_request_channel(mask, shdma_chan_filter, (void *)rspi_pd->dma_tx_id); if (rspi->chan_tx) { cfg.slave_id = rspi_pd->dma_tx_id; cfg.direction = DMA_MEM_TO_DEV; ret = dmaengine_slave_config(rspi->chan_tx, &cfg); if (!ret) dev_info(&pdev->dev, "Use DMA when tx\n"); else return ret; } } return 0; } static void rspi_release_dma(struct rspi_data *rspi) { if (rspi->chan_tx) dma_release_channel(rspi->chan_tx); if (rspi->chan_rx) dma_release_channel(rspi->chan_rx); } static int rspi_remove(struct platform_device *pdev) { struct rspi_data *rspi = dev_get_drvdata(&pdev->dev); spi_unregister_master(rspi->master); rspi_release_dma(rspi); free_irq(platform_get_irq(pdev, 0), rspi); clk_put(rspi->clk); iounmap(rspi->addr); spi_master_put(rspi->master); return 0; } static int 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; } rspi->irq = irq; ret = rspi_request_dma(rspi, pdev); if (ret < 0) { dev_err(&pdev->dev, "rspi_request_dma failed.\n"); goto error4; } 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: rspi_release_dma(rspi); 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 = 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");