/* * Microchip PIC32 SPI controller driver. * * Purna Chandra Mandal * Copyright (c) 2016, Microchip Technology Inc. * * This program is free software; you can distribute it and/or modify it * under the terms 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. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* SPI controller registers */ struct pic32_spi_regs { u32 ctrl; u32 ctrl_clr; u32 ctrl_set; u32 ctrl_inv; u32 status; u32 status_clr; u32 status_set; u32 status_inv; u32 buf; u32 dontuse[3]; u32 baud; u32 dontuse2[3]; u32 ctrl2; u32 ctrl2_clr; u32 ctrl2_set; u32 ctrl2_inv; }; /* Bit fields of SPI Control Register */ #define CTRL_RX_INT_SHIFT 0 /* Rx interrupt generation */ #define RX_FIFO_EMPTY 0 #define RX_FIFO_NOT_EMPTY 1 /* not empty */ #define RX_FIFO_HALF_FULL 2 /* full by half or more */ #define RX_FIFO_FULL 3 /* completely full */ #define CTRL_TX_INT_SHIFT 2 /* TX interrupt generation */ #define TX_FIFO_ALL_EMPTY 0 /* completely empty */ #define TX_FIFO_EMPTY 1 /* empty */ #define TX_FIFO_HALF_EMPTY 2 /* empty by half or more */ #define TX_FIFO_NOT_FULL 3 /* atleast one empty */ #define CTRL_MSTEN BIT(5) /* enable master mode */ #define CTRL_CKP BIT(6) /* active low */ #define CTRL_CKE BIT(8) /* Tx on falling edge */ #define CTRL_SMP BIT(9) /* Rx at middle or end of tx */ #define CTRL_BPW_MASK 0x03 /* bits per word/sample */ #define CTRL_BPW_SHIFT 10 #define PIC32_BPW_8 0 #define PIC32_BPW_16 1 #define PIC32_BPW_32 2 #define CTRL_SIDL BIT(13) /* sleep when idle */ #define CTRL_ON BIT(15) /* enable macro */ #define CTRL_ENHBUF BIT(16) /* enable enhanced buffering */ #define CTRL_MCLKSEL BIT(23) /* select clock source */ #define CTRL_MSSEN BIT(28) /* macro driven /SS */ #define CTRL_FRMEN BIT(31) /* enable framing mode */ /* Bit fields of SPI Status Register */ #define STAT_RF_EMPTY BIT(5) /* RX Fifo empty */ #define STAT_RX_OV BIT(6) /* err, s/w needs to clear */ #define STAT_TX_UR BIT(8) /* UR in Framed SPI modes */ #define STAT_FRM_ERR BIT(12) /* Multiple Frame Sync pulse */ #define STAT_TF_LVL_MASK 0x1F #define STAT_TF_LVL_SHIFT 16 #define STAT_RF_LVL_MASK 0x1F #define STAT_RF_LVL_SHIFT 24 /* Bit fields of SPI Baud Register */ #define BAUD_MASK 0x1ff /* Bit fields of SPI Control2 Register */ #define CTRL2_TX_UR_EN BIT(10) /* Enable int on Tx under-run */ #define CTRL2_RX_OV_EN BIT(11) /* Enable int on Rx over-run */ #define CTRL2_FRM_ERR_EN BIT(12) /* Enable frame err int */ /* Minimum DMA transfer size */ #define PIC32_DMA_LEN_MIN 64 struct pic32_spi { dma_addr_t dma_base; struct pic32_spi_regs __iomem *regs; int fault_irq; int rx_irq; int tx_irq; u32 fifo_n_byte; /* FIFO depth in bytes */ struct clk *clk; struct spi_master *master; /* Current controller setting */ u32 speed_hz; /* spi-clk rate */ u32 mode; u32 bits_per_word; u32 fifo_n_elm; /* FIFO depth in words */ #define PIC32F_DMA_PREP 0 /* DMA chnls configured */ unsigned long flags; /* Current transfer state */ struct completion xfer_done; /* PIO transfer specific */ const void *tx; const void *tx_end; const void *rx; const void *rx_end; int len; void (*rx_fifo)(struct pic32_spi *); void (*tx_fifo)(struct pic32_spi *); }; static inline void pic32_spi_enable(struct pic32_spi *pic32s) { writel(CTRL_ON | CTRL_SIDL, &pic32s->regs->ctrl_set); } static inline void pic32_spi_disable(struct pic32_spi *pic32s) { writel(CTRL_ON | CTRL_SIDL, &pic32s->regs->ctrl_clr); /* avoid SPI registers read/write at immediate next CPU clock */ ndelay(20); } static void pic32_spi_set_clk_rate(struct pic32_spi *pic32s, u32 spi_ck) { u32 div; /* div = (clk_in / 2 * spi_ck) - 1 */ div = DIV_ROUND_CLOSEST(clk_get_rate(pic32s->clk), 2 * spi_ck) - 1; writel(div & BAUD_MASK, &pic32s->regs->baud); } static inline u32 pic32_rx_fifo_level(struct pic32_spi *pic32s) { u32 sr = readl(&pic32s->regs->status); return (sr >> STAT_RF_LVL_SHIFT) & STAT_RF_LVL_MASK; } static inline u32 pic32_tx_fifo_level(struct pic32_spi *pic32s) { u32 sr = readl(&pic32s->regs->status); return (sr >> STAT_TF_LVL_SHIFT) & STAT_TF_LVL_MASK; } /* Return the max entries we can fill into tx fifo */ static u32 pic32_tx_max(struct pic32_spi *pic32s, int n_bytes) { u32 tx_left, tx_room, rxtx_gap; tx_left = (pic32s->tx_end - pic32s->tx) / n_bytes; tx_room = pic32s->fifo_n_elm - pic32_tx_fifo_level(pic32s); /* * Another concern is about the tx/rx mismatch, we * though to use (pic32s->fifo_n_byte - rxfl - txfl) as * one maximum value for tx, but it doesn't cover the * data which is out of tx/rx fifo and inside the * shift registers. So a ctrl from sw point of * view is taken. */ rxtx_gap = ((pic32s->rx_end - pic32s->rx) - (pic32s->tx_end - pic32s->tx)) / n_bytes; return min3(tx_left, tx_room, (u32)(pic32s->fifo_n_elm - rxtx_gap)); } /* Return the max entries we should read out of rx fifo */ static u32 pic32_rx_max(struct pic32_spi *pic32s, int n_bytes) { u32 rx_left = (pic32s->rx_end - pic32s->rx) / n_bytes; return min_t(u32, rx_left, pic32_rx_fifo_level(pic32s)); } #define BUILD_SPI_FIFO_RW(__name, __type, __bwl) \ static void pic32_spi_rx_##__name(struct pic32_spi *pic32s) \ { \ __type v; \ u32 mx = pic32_rx_max(pic32s, sizeof(__type)); \ for (; mx; mx--) { \ v = read##__bwl(&pic32s->regs->buf); \ if (pic32s->rx_end - pic32s->len) \ *(__type *)(pic32s->rx) = v; \ pic32s->rx += sizeof(__type); \ } \ } \ \ static void pic32_spi_tx_##__name(struct pic32_spi *pic32s) \ { \ __type v; \ u32 mx = pic32_tx_max(pic32s, sizeof(__type)); \ for (; mx ; mx--) { \ v = (__type)~0U; \ if (pic32s->tx_end - pic32s->len) \ v = *(__type *)(pic32s->tx); \ write##__bwl(v, &pic32s->regs->buf); \ pic32s->tx += sizeof(__type); \ } \ } BUILD_SPI_FIFO_RW(byte, u8, b); BUILD_SPI_FIFO_RW(word, u16, w); BUILD_SPI_FIFO_RW(dword, u32, l); static void pic32_err_stop(struct pic32_spi *pic32s, const char *msg) { /* disable all interrupts */ disable_irq_nosync(pic32s->fault_irq); disable_irq_nosync(pic32s->rx_irq); disable_irq_nosync(pic32s->tx_irq); /* Show err message and abort xfer with err */ dev_err(&pic32s->master->dev, "%s\n", msg); if (pic32s->master->cur_msg) pic32s->master->cur_msg->status = -EIO; complete(&pic32s->xfer_done); } static irqreturn_t pic32_spi_fault_irq(int irq, void *dev_id) { struct pic32_spi *pic32s = dev_id; u32 status; status = readl(&pic32s->regs->status); /* Error handling */ if (status & (STAT_RX_OV | STAT_TX_UR)) { writel(STAT_RX_OV, &pic32s->regs->status_clr); writel(STAT_TX_UR, &pic32s->regs->status_clr); pic32_err_stop(pic32s, "err_irq: fifo ov/ur-run\n"); return IRQ_HANDLED; } if (status & STAT_FRM_ERR) { pic32_err_stop(pic32s, "err_irq: frame error"); return IRQ_HANDLED; } if (!pic32s->master->cur_msg) { pic32_err_stop(pic32s, "err_irq: no mesg"); return IRQ_NONE; } return IRQ_NONE; } static irqreturn_t pic32_spi_rx_irq(int irq, void *dev_id) { struct pic32_spi *pic32s = dev_id; pic32s->rx_fifo(pic32s); /* rx complete ? */ if (pic32s->rx_end == pic32s->rx) { /* disable all interrupts */ disable_irq_nosync(pic32s->fault_irq); disable_irq_nosync(pic32s->rx_irq); /* complete current xfer */ complete(&pic32s->xfer_done); } return IRQ_HANDLED; } static irqreturn_t pic32_spi_tx_irq(int irq, void *dev_id) { struct pic32_spi *pic32s = dev_id; pic32s->tx_fifo(pic32s); /* tx complete? disable tx interrupt */ if (pic32s->tx_end == pic32s->tx) disable_irq_nosync(pic32s->tx_irq); return IRQ_HANDLED; } static void pic32_spi_dma_rx_notify(void *data) { struct pic32_spi *pic32s = data; complete(&pic32s->xfer_done); } static int pic32_spi_dma_transfer(struct pic32_spi *pic32s, struct spi_transfer *xfer) { struct spi_master *master = pic32s->master; struct dma_async_tx_descriptor *desc_rx; struct dma_async_tx_descriptor *desc_tx; dma_cookie_t cookie; int ret; if (!master->dma_rx || !master->dma_tx) return -ENODEV; desc_rx = dmaengine_prep_slave_sg(master->dma_rx, xfer->rx_sg.sgl, xfer->rx_sg.nents, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc_rx) { ret = -EINVAL; goto err_dma; } desc_tx = dmaengine_prep_slave_sg(master->dma_tx, xfer->tx_sg.sgl, xfer->tx_sg.nents, DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc_tx) { ret = -EINVAL; goto err_dma; } /* Put callback on the RX transfer, that should finish last */ desc_rx->callback = pic32_spi_dma_rx_notify; desc_rx->callback_param = pic32s; cookie = dmaengine_submit(desc_rx); ret = dma_submit_error(cookie); if (ret) goto err_dma; cookie = dmaengine_submit(desc_tx); ret = dma_submit_error(cookie); if (ret) goto err_dma_tx; dma_async_issue_pending(master->dma_rx); dma_async_issue_pending(master->dma_tx); return 0; err_dma_tx: dmaengine_terminate_all(master->dma_rx); err_dma: return ret; } static int pic32_spi_dma_config(struct pic32_spi *pic32s, u32 dma_width) { int buf_offset = offsetof(struct pic32_spi_regs, buf); struct spi_master *master = pic32s->master; struct dma_slave_config cfg; int ret; cfg.device_fc = true; cfg.src_addr = pic32s->dma_base + buf_offset; cfg.dst_addr = pic32s->dma_base + buf_offset; cfg.src_maxburst = pic32s->fifo_n_elm / 2; /* fill one-half */ cfg.dst_maxburst = pic32s->fifo_n_elm / 2; /* drain one-half */ cfg.src_addr_width = dma_width; cfg.dst_addr_width = dma_width; /* tx channel */ cfg.slave_id = pic32s->tx_irq; cfg.direction = DMA_MEM_TO_DEV; ret = dmaengine_slave_config(master->dma_tx, &cfg); if (ret) { dev_err(&master->dev, "tx channel setup failed\n"); return ret; } /* rx channel */ cfg.slave_id = pic32s->rx_irq; cfg.direction = DMA_DEV_TO_MEM; ret = dmaengine_slave_config(master->dma_rx, &cfg); if (ret) dev_err(&master->dev, "rx channel setup failed\n"); return ret; } static int pic32_spi_set_word_size(struct pic32_spi *pic32s, u8 bits_per_word) { enum dma_slave_buswidth dmawidth; u32 buswidth, v; switch (bits_per_word) { case 8: pic32s->rx_fifo = pic32_spi_rx_byte; pic32s->tx_fifo = pic32_spi_tx_byte; buswidth = PIC32_BPW_8; dmawidth = DMA_SLAVE_BUSWIDTH_1_BYTE; break; case 16: pic32s->rx_fifo = pic32_spi_rx_word; pic32s->tx_fifo = pic32_spi_tx_word; buswidth = PIC32_BPW_16; dmawidth = DMA_SLAVE_BUSWIDTH_2_BYTES; break; case 32: pic32s->rx_fifo = pic32_spi_rx_dword; pic32s->tx_fifo = pic32_spi_tx_dword; buswidth = PIC32_BPW_32; dmawidth = DMA_SLAVE_BUSWIDTH_4_BYTES; break; default: /* not supported */ return -EINVAL; } /* calculate maximum number of words fifos can hold */ pic32s->fifo_n_elm = DIV_ROUND_UP(pic32s->fifo_n_byte, bits_per_word / 8); /* set word size */ v = readl(&pic32s->regs->ctrl); v &= ~(CTRL_BPW_MASK << CTRL_BPW_SHIFT); v |= buswidth << CTRL_BPW_SHIFT; writel(v, &pic32s->regs->ctrl); /* re-configure dma width, if required */ if (test_bit(PIC32F_DMA_PREP, &pic32s->flags)) pic32_spi_dma_config(pic32s, dmawidth); return 0; } static int pic32_spi_prepare_hardware(struct spi_master *master) { struct pic32_spi *pic32s = spi_master_get_devdata(master); pic32_spi_enable(pic32s); return 0; } static int pic32_spi_prepare_message(struct spi_master *master, struct spi_message *msg) { struct pic32_spi *pic32s = spi_master_get_devdata(master); struct spi_device *spi = msg->spi; u32 val; /* set device specific bits_per_word */ if (pic32s->bits_per_word != spi->bits_per_word) { pic32_spi_set_word_size(pic32s, spi->bits_per_word); pic32s->bits_per_word = spi->bits_per_word; } /* device specific speed change */ if (pic32s->speed_hz != spi->max_speed_hz) { pic32_spi_set_clk_rate(pic32s, spi->max_speed_hz); pic32s->speed_hz = spi->max_speed_hz; } /* device specific mode change */ if (pic32s->mode != spi->mode) { val = readl(&pic32s->regs->ctrl); /* active low */ if (spi->mode & SPI_CPOL) val |= CTRL_CKP; else val &= ~CTRL_CKP; /* tx on rising edge */ if (spi->mode & SPI_CPHA) val &= ~CTRL_CKE; else val |= CTRL_CKE; /* rx at end of tx */ val |= CTRL_SMP; writel(val, &pic32s->regs->ctrl); pic32s->mode = spi->mode; } return 0; } static bool pic32_spi_can_dma(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) { struct pic32_spi *pic32s = spi_master_get_devdata(master); /* skip using DMA on small size transfer to avoid overhead.*/ return (xfer->len >= PIC32_DMA_LEN_MIN) && test_bit(PIC32F_DMA_PREP, &pic32s->flags); } static int pic32_spi_one_transfer(struct spi_master *master, struct spi_device *spi, struct spi_transfer *transfer) { struct pic32_spi *pic32s; bool dma_issued = false; unsigned long timeout; int ret; pic32s = spi_master_get_devdata(master); /* handle transfer specific word size change */ if (transfer->bits_per_word && (transfer->bits_per_word != pic32s->bits_per_word)) { ret = pic32_spi_set_word_size(pic32s, transfer->bits_per_word); if (ret) return ret; pic32s->bits_per_word = transfer->bits_per_word; } /* handle transfer specific speed change */ if (transfer->speed_hz && (transfer->speed_hz != pic32s->speed_hz)) { pic32_spi_set_clk_rate(pic32s, transfer->speed_hz); pic32s->speed_hz = transfer->speed_hz; } reinit_completion(&pic32s->xfer_done); /* transact by DMA mode */ if (transfer->rx_sg.nents && transfer->tx_sg.nents) { ret = pic32_spi_dma_transfer(pic32s, transfer); if (ret) { dev_err(&spi->dev, "dma submit error\n"); return ret; } /* DMA issued */ dma_issued = true; } else { /* set current transfer information */ pic32s->tx = (const void *)transfer->tx_buf; pic32s->rx = (const void *)transfer->rx_buf; pic32s->tx_end = pic32s->tx + transfer->len; pic32s->rx_end = pic32s->rx + transfer->len; pic32s->len = transfer->len; /* transact by interrupt driven PIO */ enable_irq(pic32s->fault_irq); enable_irq(pic32s->rx_irq); enable_irq(pic32s->tx_irq); } /* wait for completion */ timeout = wait_for_completion_timeout(&pic32s->xfer_done, 2 * HZ); if (timeout == 0) { dev_err(&spi->dev, "wait error/timedout\n"); if (dma_issued) { dmaengine_terminate_all(master->dma_rx); dmaengine_terminate_all(master->dma_rx); } ret = -ETIMEDOUT; } else { ret = 0; } return ret; } static int pic32_spi_unprepare_message(struct spi_master *master, struct spi_message *msg) { /* nothing to do */ return 0; } static int pic32_spi_unprepare_hardware(struct spi_master *master) { struct pic32_spi *pic32s = spi_master_get_devdata(master); pic32_spi_disable(pic32s); return 0; } /* This may be called multiple times by same spi dev */ static int pic32_spi_setup(struct spi_device *spi) { if (!spi->max_speed_hz) { dev_err(&spi->dev, "No max speed HZ parameter\n"); return -EINVAL; } /* PIC32 spi controller can drive /CS during transfer depending * on tx fifo fill-level. /CS will stay asserted as long as TX * fifo is non-empty, else will be deasserted indicating * completion of the ongoing transfer. This might result into * unreliable/erroneous SPI transactions. * To avoid that we will always handle /CS by toggling GPIO. */ if (!gpio_is_valid(spi->cs_gpio)) return -EINVAL; gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); return 0; } static void pic32_spi_cleanup(struct spi_device *spi) { /* de-activate cs-gpio */ gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); } static void pic32_spi_dma_prep(struct pic32_spi *pic32s, struct device *dev) { struct spi_master *master = pic32s->master; dma_cap_mask_t mask; dma_cap_zero(mask); dma_cap_set(DMA_SLAVE, mask); master->dma_rx = dma_request_slave_channel_compat(mask, NULL, NULL, dev, "spi-rx"); if (!master->dma_rx) { dev_warn(dev, "RX channel not found.\n"); goto out_err; } master->dma_tx = dma_request_slave_channel_compat(mask, NULL, NULL, dev, "spi-tx"); if (!master->dma_tx) { dev_warn(dev, "TX channel not found.\n"); goto out_err; } if (pic32_spi_dma_config(pic32s, DMA_SLAVE_BUSWIDTH_1_BYTE)) goto out_err; /* DMA chnls allocated and prepared */ set_bit(PIC32F_DMA_PREP, &pic32s->flags); return; out_err: if (master->dma_rx) dma_release_channel(master->dma_rx); if (master->dma_tx) dma_release_channel(master->dma_tx); } static void pic32_spi_dma_unprep(struct pic32_spi *pic32s) { if (!test_bit(PIC32F_DMA_PREP, &pic32s->flags)) return; clear_bit(PIC32F_DMA_PREP, &pic32s->flags); if (pic32s->master->dma_rx) dma_release_channel(pic32s->master->dma_rx); if (pic32s->master->dma_tx) dma_release_channel(pic32s->master->dma_tx); } static void pic32_spi_hw_init(struct pic32_spi *pic32s) { u32 ctrl; /* disable hardware */ pic32_spi_disable(pic32s); ctrl = readl(&pic32s->regs->ctrl); /* enable enhanced fifo of 128bit deep */ ctrl |= CTRL_ENHBUF; pic32s->fifo_n_byte = 16; /* disable framing mode */ ctrl &= ~CTRL_FRMEN; /* enable master mode while disabled */ ctrl |= CTRL_MSTEN; /* set tx fifo threshold interrupt */ ctrl &= ~(0x3 << CTRL_TX_INT_SHIFT); ctrl |= (TX_FIFO_HALF_EMPTY << CTRL_TX_INT_SHIFT); /* set rx fifo threshold interrupt */ ctrl &= ~(0x3 << CTRL_RX_INT_SHIFT); ctrl |= (RX_FIFO_NOT_EMPTY << CTRL_RX_INT_SHIFT); /* select clk source */ ctrl &= ~CTRL_MCLKSEL; /* set manual /CS mode */ ctrl &= ~CTRL_MSSEN; writel(ctrl, &pic32s->regs->ctrl); /* enable error reporting */ ctrl = CTRL2_TX_UR_EN | CTRL2_RX_OV_EN | CTRL2_FRM_ERR_EN; writel(ctrl, &pic32s->regs->ctrl2_set); } static int pic32_spi_hw_probe(struct platform_device *pdev, struct pic32_spi *pic32s) { struct resource *mem; int ret; mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); pic32s->regs = devm_ioremap_resource(&pdev->dev, mem); if (IS_ERR(pic32s->regs)) return PTR_ERR(pic32s->regs); pic32s->dma_base = mem->start; /* get irq resources: err-irq, rx-irq, tx-irq */ pic32s->fault_irq = platform_get_irq_byname(pdev, "fault"); if (pic32s->fault_irq < 0) { dev_err(&pdev->dev, "fault-irq not found\n"); return pic32s->fault_irq; } pic32s->rx_irq = platform_get_irq_byname(pdev, "rx"); if (pic32s->rx_irq < 0) { dev_err(&pdev->dev, "rx-irq not found\n"); return pic32s->rx_irq; } pic32s->tx_irq = platform_get_irq_byname(pdev, "tx"); if (pic32s->tx_irq < 0) { dev_err(&pdev->dev, "tx-irq not found\n"); return pic32s->tx_irq; } /* get clock */ pic32s->clk = devm_clk_get(&pdev->dev, "mck0"); if (IS_ERR(pic32s->clk)) { dev_err(&pdev->dev, "clk not found\n"); ret = PTR_ERR(pic32s->clk); goto err_unmap_mem; } ret = clk_prepare_enable(pic32s->clk); if (ret) goto err_unmap_mem; pic32_spi_hw_init(pic32s); return 0; err_unmap_mem: dev_err(&pdev->dev, "%s failed, err %d\n", __func__, ret); return ret; } static int pic32_spi_probe(struct platform_device *pdev) { struct spi_master *master; struct pic32_spi *pic32s; int ret; master = spi_alloc_master(&pdev->dev, sizeof(*pic32s)); if (!master) return -ENOMEM; pic32s = spi_master_get_devdata(master); pic32s->master = master; ret = pic32_spi_hw_probe(pdev, pic32s); if (ret) goto err_master; master->dev.of_node = of_node_get(pdev->dev.of_node); master->mode_bits = SPI_MODE_3 | SPI_MODE_0 | SPI_CS_HIGH; master->num_chipselect = 1; /* single chip-select */ master->max_speed_hz = clk_get_rate(pic32s->clk); master->setup = pic32_spi_setup; master->cleanup = pic32_spi_cleanup; master->flags = SPI_MASTER_MUST_TX | SPI_MASTER_MUST_RX; master->bits_per_word_mask = SPI_BPW_MASK(8) | SPI_BPW_MASK(16) | SPI_BPW_MASK(32); master->transfer_one = pic32_spi_one_transfer; master->prepare_message = pic32_spi_prepare_message; master->unprepare_message = pic32_spi_unprepare_message; master->prepare_transfer_hardware = pic32_spi_prepare_hardware; master->unprepare_transfer_hardware = pic32_spi_unprepare_hardware; /* optional DMA support */ pic32_spi_dma_prep(pic32s, &pdev->dev); if (test_bit(PIC32F_DMA_PREP, &pic32s->flags)) master->can_dma = pic32_spi_can_dma; init_completion(&pic32s->xfer_done); pic32s->mode = -1; /* install irq handlers (with irq-disabled) */ irq_set_status_flags(pic32s->fault_irq, IRQ_NOAUTOEN); ret = devm_request_irq(&pdev->dev, pic32s->fault_irq, pic32_spi_fault_irq, IRQF_NO_THREAD, dev_name(&pdev->dev), pic32s); if (ret < 0) { dev_err(&pdev->dev, "request fault-irq %d\n", pic32s->rx_irq); goto err_bailout; } /* receive interrupt handler */ irq_set_status_flags(pic32s->rx_irq, IRQ_NOAUTOEN); ret = devm_request_irq(&pdev->dev, pic32s->rx_irq, pic32_spi_rx_irq, IRQF_NO_THREAD, dev_name(&pdev->dev), pic32s); if (ret < 0) { dev_err(&pdev->dev, "request rx-irq %d\n", pic32s->rx_irq); goto err_bailout; } /* transmit interrupt handler */ irq_set_status_flags(pic32s->tx_irq, IRQ_NOAUTOEN); ret = devm_request_irq(&pdev->dev, pic32s->tx_irq, pic32_spi_tx_irq, IRQF_NO_THREAD, dev_name(&pdev->dev), pic32s); if (ret < 0) { dev_err(&pdev->dev, "request tx-irq %d\n", pic32s->tx_irq); goto err_bailout; } /* register master */ ret = devm_spi_register_master(&pdev->dev, master); if (ret) { dev_err(&master->dev, "failed registering spi master\n"); goto err_bailout; } platform_set_drvdata(pdev, pic32s); return 0; err_bailout: clk_disable_unprepare(pic32s->clk); err_master: spi_master_put(master); return ret; } static int pic32_spi_remove(struct platform_device *pdev) { struct pic32_spi *pic32s; pic32s = platform_get_drvdata(pdev); pic32_spi_disable(pic32s); clk_disable_unprepare(pic32s->clk); pic32_spi_dma_unprep(pic32s); return 0; } static const struct of_device_id pic32_spi_of_match[] = { {.compatible = "microchip,pic32mzda-spi",}, {}, }; MODULE_DEVICE_TABLE(of, pic32_spi_of_match); static struct platform_driver pic32_spi_driver = { .driver = { .name = "spi-pic32", .of_match_table = of_match_ptr(pic32_spi_of_match), }, .probe = pic32_spi_probe, .remove = pic32_spi_remove, }; module_platform_driver(pic32_spi_driver); MODULE_AUTHOR("Purna Chandra Mandal "); MODULE_DESCRIPTION("Microchip SPI driver for PIC32 SPI controller."); MODULE_LICENSE("GPL v2");