diff options
Diffstat (limited to 'drivers/spi/atmel_spi.c')
| -rw-r--r-- | drivers/spi/atmel_spi.c | 940 |
1 files changed, 0 insertions, 940 deletions
diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c deleted file mode 100644 index 08711e9202ab..000000000000 --- a/drivers/spi/atmel_spi.c +++ /dev/null @@ -1,940 +0,0 @@ -/* - * Driver for Atmel AT32 and AT91 SPI Controllers - * - * Copyright (C) 2006 Atmel Corporation - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#include <linux/kernel.h> -#include <linux/init.h> -#include <linux/clk.h> -#include <linux/module.h> -#include <linux/platform_device.h> -#include <linux/delay.h> -#include <linux/dma-mapping.h> -#include <linux/err.h> -#include <linux/interrupt.h> -#include <linux/spi/spi.h> -#include <linux/slab.h> - -#include <asm/io.h> -#include <mach/board.h> -#include <mach/gpio.h> -#include <mach/cpu.h> - -#include "atmel_spi.h" - -/* - * The core SPI transfer engine just talks to a register bank to set up - * DMA transfers; transfer queue progress is driven by IRQs. The clock - * framework provides the base clock, subdivided for each spi_device. - */ -struct atmel_spi { - spinlock_t lock; - - void __iomem *regs; - int irq; - struct clk *clk; - struct platform_device *pdev; - struct spi_device *stay; - - u8 stopping; - struct list_head queue; - struct spi_transfer *current_transfer; - unsigned long current_remaining_bytes; - struct spi_transfer *next_transfer; - unsigned long next_remaining_bytes; - - void *buffer; - dma_addr_t buffer_dma; -}; - -/* Controller-specific per-slave state */ -struct atmel_spi_device { - unsigned int npcs_pin; - u32 csr; -}; - -#define BUFFER_SIZE PAGE_SIZE -#define INVALID_DMA_ADDRESS 0xffffffff - -/* - * Version 2 of the SPI controller has - * - CR.LASTXFER - * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) - * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) - * - SPI_CSRx.CSAAT - * - SPI_CSRx.SBCR allows faster clocking - * - * We can determine the controller version by reading the VERSION - * register, but I haven't checked that it exists on all chips, and - * this is cheaper anyway. - */ -static bool atmel_spi_is_v2(void) -{ - return !cpu_is_at91rm9200(); -} - -/* - * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby - * they assume that spi slave device state will not change on deselect, so - * that automagic deselection is OK. ("NPCSx rises if no data is to be - * transmitted") Not so! Workaround uses nCSx pins as GPIOs; or newer - * controllers have CSAAT and friends. - * - * Since the CSAAT functionality is a bit weird on newer controllers as - * well, we use GPIO to control nCSx pins on all controllers, updating - * MR.PCS to avoid confusing the controller. Using GPIOs also lets us - * support active-high chipselects despite the controller's belief that - * only active-low devices/systems exists. - * - * However, at91rm9200 has a second erratum whereby nCS0 doesn't work - * right when driven with GPIO. ("Mode Fault does not allow more than one - * Master on Chip Select 0.") No workaround exists for that ... so for - * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH, - * and (c) will trigger that first erratum in some cases. - * - * TODO: Test if the atmel_spi_is_v2() branch below works on - * AT91RM9200 if we use some other register than CSR0. However, don't - * do this unconditionally since AP7000 has an errata where the BITS - * field in CSR0 overrides all other CSRs. - */ - -static void cs_activate(struct atmel_spi *as, struct spi_device *spi) -{ - struct atmel_spi_device *asd = spi->controller_state; - unsigned active = spi->mode & SPI_CS_HIGH; - u32 mr; - - if (atmel_spi_is_v2()) { - /* - * Always use CSR0. This ensures that the clock - * switches to the correct idle polarity before we - * toggle the CS. - */ - spi_writel(as, CSR0, asd->csr); - spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS) - | SPI_BIT(MSTR)); - mr = spi_readl(as, MR); - gpio_set_value(asd->npcs_pin, active); - } else { - u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0; - int i; - u32 csr; - - /* Make sure clock polarity is correct */ - for (i = 0; i < spi->master->num_chipselect; i++) { - csr = spi_readl(as, CSR0 + 4 * i); - if ((csr ^ cpol) & SPI_BIT(CPOL)) - spi_writel(as, CSR0 + 4 * i, - csr ^ SPI_BIT(CPOL)); - } - - mr = spi_readl(as, MR); - mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr); - if (spi->chip_select != 0) - gpio_set_value(asd->npcs_pin, active); - spi_writel(as, MR, mr); - } - - dev_dbg(&spi->dev, "activate %u%s, mr %08x\n", - asd->npcs_pin, active ? " (high)" : "", - mr); -} - -static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi) -{ - struct atmel_spi_device *asd = spi->controller_state; - unsigned active = spi->mode & SPI_CS_HIGH; - u32 mr; - - /* only deactivate *this* device; sometimes transfers to - * another device may be active when this routine is called. - */ - mr = spi_readl(as, MR); - if (~SPI_BFEXT(PCS, mr) & (1 << spi->chip_select)) { - mr = SPI_BFINS(PCS, 0xf, mr); - spi_writel(as, MR, mr); - } - - dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n", - asd->npcs_pin, active ? " (low)" : "", - mr); - - if (atmel_spi_is_v2() || spi->chip_select != 0) - gpio_set_value(asd->npcs_pin, !active); -} - -static inline int atmel_spi_xfer_is_last(struct spi_message *msg, - struct spi_transfer *xfer) -{ - return msg->transfers.prev == &xfer->transfer_list; -} - -static inline int atmel_spi_xfer_can_be_chained(struct spi_transfer *xfer) -{ - return xfer->delay_usecs == 0 && !xfer->cs_change; -} - -static void atmel_spi_next_xfer_data(struct spi_master *master, - struct spi_transfer *xfer, - dma_addr_t *tx_dma, - dma_addr_t *rx_dma, - u32 *plen) -{ - struct atmel_spi *as = spi_master_get_devdata(master); - u32 len = *plen; - - /* use scratch buffer only when rx or tx data is unspecified */ - if (xfer->rx_buf) - *rx_dma = xfer->rx_dma + xfer->len - *plen; - else { - *rx_dma = as->buffer_dma; - if (len > BUFFER_SIZE) - len = BUFFER_SIZE; - } - if (xfer->tx_buf) - *tx_dma = xfer->tx_dma + xfer->len - *plen; - else { - *tx_dma = as->buffer_dma; - if (len > BUFFER_SIZE) - len = BUFFER_SIZE; - memset(as->buffer, 0, len); - dma_sync_single_for_device(&as->pdev->dev, - as->buffer_dma, len, DMA_TO_DEVICE); - } - - *plen = len; -} - -/* - * Submit next transfer for DMA. - * lock is held, spi irq is blocked - */ -static void atmel_spi_next_xfer(struct spi_master *master, - struct spi_message *msg) -{ - struct atmel_spi *as = spi_master_get_devdata(master); - struct spi_transfer *xfer; - u32 len, remaining; - u32 ieval; - dma_addr_t tx_dma, rx_dma; - - if (!as->current_transfer) - xfer = list_entry(msg->transfers.next, - struct spi_transfer, transfer_list); - else if (!as->next_transfer) - xfer = list_entry(as->current_transfer->transfer_list.next, - struct spi_transfer, transfer_list); - else - xfer = NULL; - - if (xfer) { - spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); - - len = xfer->len; - atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len); - remaining = xfer->len - len; - - spi_writel(as, RPR, rx_dma); - spi_writel(as, TPR, tx_dma); - - if (msg->spi->bits_per_word > 8) - len >>= 1; - spi_writel(as, RCR, len); - spi_writel(as, TCR, len); - - dev_dbg(&msg->spi->dev, - " start xfer %p: len %u tx %p/%08x rx %p/%08x\n", - xfer, xfer->len, xfer->tx_buf, xfer->tx_dma, - xfer->rx_buf, xfer->rx_dma); - } else { - xfer = as->next_transfer; - remaining = as->next_remaining_bytes; - } - - as->current_transfer = xfer; - as->current_remaining_bytes = remaining; - - if (remaining > 0) - len = remaining; - else if (!atmel_spi_xfer_is_last(msg, xfer) - && atmel_spi_xfer_can_be_chained(xfer)) { - xfer = list_entry(xfer->transfer_list.next, - struct spi_transfer, transfer_list); - len = xfer->len; - } else - xfer = NULL; - - as->next_transfer = xfer; - - if (xfer) { - u32 total; - - total = len; - atmel_spi_next_xfer_data(master, xfer, &tx_dma, &rx_dma, &len); - as->next_remaining_bytes = total - len; - - spi_writel(as, RNPR, rx_dma); - spi_writel(as, TNPR, tx_dma); - - if (msg->spi->bits_per_word > 8) - len >>= 1; - spi_writel(as, RNCR, len); - spi_writel(as, TNCR, len); - - dev_dbg(&msg->spi->dev, - " next xfer %p: len %u tx %p/%08x rx %p/%08x\n", - xfer, xfer->len, xfer->tx_buf, xfer->tx_dma, - xfer->rx_buf, xfer->rx_dma); - ieval = SPI_BIT(ENDRX) | SPI_BIT(OVRES); - } else { - spi_writel(as, RNCR, 0); - spi_writel(as, TNCR, 0); - ieval = SPI_BIT(RXBUFF) | SPI_BIT(ENDRX) | SPI_BIT(OVRES); - } - - /* REVISIT: We're waiting for ENDRX before we start the next - * transfer because we need to handle some difficult timing - * issues otherwise. If we wait for ENDTX in one transfer and - * then starts waiting for ENDRX in the next, it's difficult - * to tell the difference between the ENDRX interrupt we're - * actually waiting for and the ENDRX interrupt of the - * previous transfer. - * - * It should be doable, though. Just not now... - */ - spi_writel(as, IER, ieval); - spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN)); -} - -static void atmel_spi_next_message(struct spi_master *master) -{ - struct atmel_spi *as = spi_master_get_devdata(master); - struct spi_message *msg; - struct spi_device *spi; - - BUG_ON(as->current_transfer); - - msg = list_entry(as->queue.next, struct spi_message, queue); - spi = msg->spi; - - dev_dbg(master->dev.parent, "start message %p for %s\n", - msg, dev_name(&spi->dev)); - - /* select chip if it's not still active */ - if (as->stay) { - if (as->stay != spi) { - cs_deactivate(as, as->stay); - cs_activate(as, spi); - } - as->stay = NULL; - } else - cs_activate(as, spi); - - atmel_spi_next_xfer(master, msg); -} - -/* - * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma: - * - The buffer is either valid for CPU access, else NULL - * - If the buffer is valid, so is its DMA address - * - * This driver manages the dma address unless message->is_dma_mapped. - */ -static int -atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer) -{ - struct device *dev = &as->pdev->dev; - - xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS; - if (xfer->tx_buf) { - /* tx_buf is a const void* where we need a void * for the dma - * mapping */ - void *nonconst_tx = (void *)xfer->tx_buf; - - xfer->tx_dma = dma_map_single(dev, - nonconst_tx, xfer->len, - DMA_TO_DEVICE); - if (dma_mapping_error(dev, xfer->tx_dma)) - return -ENOMEM; - } - if (xfer->rx_buf) { - xfer->rx_dma = dma_map_single(dev, - xfer->rx_buf, xfer->len, - DMA_FROM_DEVICE); - if (dma_mapping_error(dev, xfer->rx_dma)) { - if (xfer->tx_buf) - dma_unmap_single(dev, - xfer->tx_dma, xfer->len, - DMA_TO_DEVICE); - return -ENOMEM; - } - } - return 0; -} - -static void atmel_spi_dma_unmap_xfer(struct spi_master *master, - struct spi_transfer *xfer) -{ - if (xfer->tx_dma != INVALID_DMA_ADDRESS) - dma_unmap_single(master->dev.parent, xfer->tx_dma, - xfer->len, DMA_TO_DEVICE); - if (xfer->rx_dma != INVALID_DMA_ADDRESS) - dma_unmap_single(master->dev.parent, xfer->rx_dma, - xfer->len, DMA_FROM_DEVICE); -} - -static void -atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as, - struct spi_message *msg, int status, int stay) -{ - if (!stay || status < 0) - cs_deactivate(as, msg->spi); - else - as->stay = msg->spi; - - list_del(&msg->queue); - msg->status = status; - - dev_dbg(master->dev.parent, - "xfer complete: %u bytes transferred\n", - msg->actual_length); - - spin_unlock(&as->lock); - msg->complete(msg->context); - spin_lock(&as->lock); - - as->current_transfer = NULL; - as->next_transfer = NULL; - - /* continue if needed */ - if (list_empty(&as->queue) || as->stopping) - spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); - else - atmel_spi_next_message(master); -} - -static irqreturn_t -atmel_spi_interrupt(int irq, void *dev_id) -{ - struct spi_master *master = dev_id; - struct atmel_spi *as = spi_master_get_devdata(master); - struct spi_message *msg; - struct spi_transfer *xfer; - u32 status, pending, imr; - int ret = IRQ_NONE; - - spin_lock(&as->lock); - - xfer = as->current_transfer; - msg = list_entry(as->queue.next, struct spi_message, queue); - - imr = spi_readl(as, IMR); - status = spi_readl(as, SR); - pending = status & imr; - - if (pending & SPI_BIT(OVRES)) { - int timeout; - - ret = IRQ_HANDLED; - - spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX) - | SPI_BIT(OVRES))); - - /* - * When we get an overrun, we disregard the current - * transfer. Data will not be copied back from any - * bounce buffer and msg->actual_len will not be - * updated with the last xfer. - * - * We will also not process any remaning transfers in - * the message. - * - * First, stop the transfer and unmap the DMA buffers. - */ - spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); - if (!msg->is_dma_mapped) - atmel_spi_dma_unmap_xfer(master, xfer); - - /* REVISIT: udelay in irq is unfriendly */ - if (xfer->delay_usecs) - udelay(xfer->delay_usecs); - - dev_warn(master->dev.parent, "overrun (%u/%u remaining)\n", - spi_readl(as, TCR), spi_readl(as, RCR)); - - /* - * Clean up DMA registers and make sure the data - * registers are empty. - */ - spi_writel(as, RNCR, 0); - spi_writel(as, TNCR, 0); - spi_writel(as, RCR, 0); - spi_writel(as, TCR, 0); - for (timeout = 1000; timeout; timeout--) - if (spi_readl(as, SR) & SPI_BIT(TXEMPTY)) - break; - if (!timeout) - dev_warn(master->dev.parent, - "timeout waiting for TXEMPTY"); - while (spi_readl(as, SR) & SPI_BIT(RDRF)) - spi_readl(as, RDR); - - /* Clear any overrun happening while cleaning up */ - spi_readl(as, SR); - - atmel_spi_msg_done(master, as, msg, -EIO, 0); - } else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) { - ret = IRQ_HANDLED; - - spi_writel(as, IDR, pending); - - if (as->current_remaining_bytes == 0) { - msg->actual_length += xfer->len; - - if (!msg->is_dma_mapped) - atmel_spi_dma_unmap_xfer(master, xfer); - - /* REVISIT: udelay in irq is unfriendly */ - if (xfer->delay_usecs) - udelay(xfer->delay_usecs); - - if (atmel_spi_xfer_is_last(msg, xfer)) { - /* report completed message */ - atmel_spi_msg_done(master, as, msg, 0, - xfer->cs_change); - } else { - if (xfer->cs_change) { - cs_deactivate(as, msg->spi); - udelay(1); - cs_activate(as, msg->spi); - } - - /* - * Not done yet. Submit the next transfer. - * - * FIXME handle protocol options for xfer - */ - atmel_spi_next_xfer(master, msg); - } - } else { - /* - * Keep going, we still have data to send in - * the current transfer. - */ - atmel_spi_next_xfer(master, msg); - } - } - - spin_unlock(&as->lock); - - return ret; -} - -static int atmel_spi_setup(struct spi_device *spi) -{ - struct atmel_spi *as; - struct atmel_spi_device *asd; - u32 scbr, csr; - unsigned int bits = spi->bits_per_word; - unsigned long bus_hz; - unsigned int npcs_pin; - int ret; - - as = spi_master_get_devdata(spi->master); - - if (as->stopping) - return -ESHUTDOWN; - - if (spi->chip_select > spi->master->num_chipselect) { - dev_dbg(&spi->dev, - "setup: invalid chipselect %u (%u defined)\n", - spi->chip_select, spi->master->num_chipselect); - return -EINVAL; - } - - if (bits < 8 || bits > 16) { - dev_dbg(&spi->dev, - "setup: invalid bits_per_word %u (8 to 16)\n", - bits); - return -EINVAL; - } - - /* see notes above re chipselect */ - if (!atmel_spi_is_v2() - && spi->chip_select == 0 - && (spi->mode & SPI_CS_HIGH)) { - dev_dbg(&spi->dev, "setup: can't be active-high\n"); - return -EINVAL; - } - - /* v1 chips start out at half the peripheral bus speed. */ - bus_hz = clk_get_rate(as->clk); - if (!atmel_spi_is_v2()) - bus_hz /= 2; - - if (spi->max_speed_hz) { - /* - * Calculate the lowest divider that satisfies the - * constraint, assuming div32/fdiv/mbz == 0. - */ - scbr = DIV_ROUND_UP(bus_hz, spi->max_speed_hz); - - /* - * If the resulting divider doesn't fit into the - * register bitfield, we can't satisfy the constraint. - */ - if (scbr >= (1 << SPI_SCBR_SIZE)) { - dev_dbg(&spi->dev, - "setup: %d Hz too slow, scbr %u; min %ld Hz\n", - spi->max_speed_hz, scbr, bus_hz/255); - return -EINVAL; - } - } else - /* speed zero means "as slow as possible" */ - scbr = 0xff; - - csr = SPI_BF(SCBR, scbr) | SPI_BF(BITS, bits - 8); - if (spi->mode & SPI_CPOL) - csr |= SPI_BIT(CPOL); - if (!(spi->mode & SPI_CPHA)) - csr |= SPI_BIT(NCPHA); - - /* DLYBS is mostly irrelevant since we manage chipselect using GPIOs. - * - * DLYBCT would add delays between words, slowing down transfers. - * It could potentially be useful to cope with DMA bottlenecks, but - * in those cases it's probably best to just use a lower bitrate. - */ - csr |= SPI_BF(DLYBS, 0); - csr |= SPI_BF(DLYBCT, 0); - - /* chipselect must have been muxed as GPIO (e.g. in board setup) */ - npcs_pin = (unsigned int)spi->controller_data; - asd = spi->controller_state; - if (!asd) { - asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL); - if (!asd) - return -ENOMEM; - - ret = gpio_request(npcs_pin, dev_name(&spi->dev)); - if (ret) { - kfree(asd); - return ret; - } - - asd->npcs_pin = npcs_pin; - spi->controller_state = asd; - gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH)); - } else { - unsigned long flags; - - spin_lock_irqsave(&as->lock, flags); - if (as->stay == spi) - as->stay = NULL; - cs_deactivate(as, spi); - spin_unlock_irqrestore(&as->lock, flags); - } - - asd->csr = csr; - - dev_dbg(&spi->dev, - "setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n", - bus_hz / scbr, bits, spi->mode, spi->chip_select, csr); - - if (!atmel_spi_is_v2()) - spi_writel(as, CSR0 + 4 * spi->chip_select, csr); - - return 0; -} - -static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) -{ - struct atmel_spi *as; - struct spi_transfer *xfer; - unsigned long flags; - struct device *controller = spi->master->dev.parent; - u8 bits; - struct atmel_spi_device *asd; - - as = spi_master_get_devdata(spi->master); - - dev_dbg(controller, "new message %p submitted for %s\n", - msg, dev_name(&spi->dev)); - - if (unlikely(list_empty(&msg->transfers))) - return -EINVAL; - - if (as->stopping) - return -ESHUTDOWN; - - list_for_each_entry(xfer, &msg->transfers, transfer_list) { - if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) { - dev_dbg(&spi->dev, "missing rx or tx buf\n"); - return -EINVAL; - } - - if (xfer->bits_per_word) { - asd = spi->controller_state; - bits = (asd->csr >> 4) & 0xf; - if (bits != xfer->bits_per_word - 8) { - dev_dbg(&spi->dev, "you can't yet change " - "bits_per_word in transfers\n"); - return -ENOPROTOOPT; - } - } - - /* FIXME implement these protocol options!! */ - if (xfer->speed_hz) { - dev_dbg(&spi->dev, "no protocol options yet\n"); - return -ENOPROTOOPT; - } - - /* - * DMA map early, for performance (empties dcache ASAP) and - * better fault reporting. This is a DMA-only driver. - * - * NOTE that if dma_unmap_single() ever starts to do work on - * platforms supported by this driver, we would need to clean - * up mappings for previously-mapped transfers. - */ - if (!msg->is_dma_mapped) { - if (atmel_spi_dma_map_xfer(as, xfer) < 0) - return -ENOMEM; - } - } - -#ifdef VERBOSE - list_for_each_entry(xfer, &msg->transfers, transfer_list) { - dev_dbg(controller, - " xfer %p: len %u tx %p/%08x rx %p/%08x\n", - xfer, xfer->len, - xfer->tx_buf, xfer->tx_dma, - xfer->rx_buf, xfer->rx_dma); - } -#endif - - msg->status = -EINPROGRESS; - msg->actual_length = 0; - - spin_lock_irqsave(&as->lock, flags); - list_add_tail(&msg->queue, &as->queue); - if (!as->current_transfer) - atmel_spi_next_message(spi->master); - spin_unlock_irqrestore(&as->lock, flags); - - return 0; -} - -static void atmel_spi_cleanup(struct spi_device *spi) -{ - struct atmel_spi *as = spi_master_get_devdata(spi->master); - struct atmel_spi_device *asd = spi->controller_state; - unsigned gpio = (unsigned) spi->controller_data; - unsigned long flags; - - if (!asd) - return; - - spin_lock_irqsave(&as->lock, flags); - if (as->stay == spi) { - as->stay = NULL; - cs_deactivate(as, spi); - } - spin_unlock_irqrestore(&as->lock, flags); - - spi->controller_state = NULL; - gpio_free(gpio); - kfree(asd); -} - -/*-------------------------------------------------------------------------*/ - -static int __init atmel_spi_probe(struct platform_device *pdev) -{ - struct resource *regs; - int irq; - struct clk *clk; - int ret; - struct spi_master *master; - struct atmel_spi *as; - - regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!regs) - return -ENXIO; - - irq = platform_get_irq(pdev, 0); - if (irq < 0) - return irq; - - clk = clk_get(&pdev->dev, "spi_clk"); - if (IS_ERR(clk)) - return PTR_ERR(clk); - - /* setup spi core then atmel-specific driver state */ - ret = -ENOMEM; - master = spi_alloc_master(&pdev->dev, sizeof *as); - if (!master) - goto out_free; - - /* the spi->mode bits understood by this driver: */ - master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; - - master->bus_num = pdev->id; - master->num_chipselect = 4; - master->setup = atmel_spi_setup; - master->transfer = atmel_spi_transfer; - master->cleanup = atmel_spi_cleanup; - platform_set_drvdata(pdev, master); - - as = spi_master_get_devdata(master); - - /* - * Scratch buffer is used for throwaway rx and tx data. - * It's coherent to minimize dcache pollution. - */ - as->buffer = dma_alloc_coherent(&pdev->dev, BUFFER_SIZE, - &as->buffer_dma, GFP_KERNEL); - if (!as->buffer) - goto out_free; - - spin_lock_init(&as->lock); - INIT_LIST_HEAD(&as->queue); - as->pdev = pdev; - as->regs = ioremap(regs->start, resource_size(regs)); - if (!as->regs) - goto out_free_buffer; - as->irq = irq; - as->clk = clk; - - ret = request_irq(irq, atmel_spi_interrupt, 0, - dev_name(&pdev->dev), master); - if (ret) - goto out_unmap_regs; - - /* Initialize the hardware */ - clk_enable(clk); - spi_writel(as, CR, SPI_BIT(SWRST)); - spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ - spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS)); - spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); - spi_writel(as, CR, SPI_BIT(SPIEN)); - - /* go! */ - dev_info(&pdev->dev, "Atmel SPI Controller at 0x%08lx (irq %d)\n", - (unsigned long)regs->start, irq); - - ret = spi_register_master(master); - if (ret) - goto out_reset_hw; - - return 0; - -out_reset_hw: - spi_writel(as, CR, SPI_BIT(SWRST)); - spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ - clk_disable(clk); - free_irq(irq, master); -out_unmap_regs: - iounmap(as->regs); -out_free_buffer: - dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer, - as->buffer_dma); -out_free: - clk_put(clk); - spi_master_put(master); - return ret; -} - -static int __exit atmel_spi_remove(struct platform_device *pdev) -{ - struct spi_master *master = platform_get_drvdata(pdev); - struct atmel_spi *as = spi_master_get_devdata(master); - struct spi_message *msg; - - /* reset the hardware and block queue progress */ - spin_lock_irq(&as->lock); - as->stopping = 1; - spi_writel(as, CR, SPI_BIT(SWRST)); - spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ - spi_readl(as, SR); - spin_unlock_irq(&as->lock); - - /* Terminate remaining queued transfers */ - list_for_each_entry(msg, &as->queue, queue) { - /* REVISIT unmapping the dma is a NOP on ARM and AVR32 - * but we shouldn't depend on that... - */ - msg->status = -ESHUTDOWN; - msg->complete(msg->context); - } - - dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer, - as->buffer_dma); - - clk_disable(as->clk); - clk_put(as->clk); - free_irq(as->irq, master); - iounmap(as->regs); - - spi_unregister_master(master); - - return 0; -} - -#ifdef CONFIG_PM - -static int atmel_spi_suspend(struct platform_device *pdev, pm_message_t mesg) -{ - struct spi_master *master = platform_get_drvdata(pdev); - struct atmel_spi *as = spi_master_get_devdata(master); - - clk_disable(as->clk); - return 0; -} - -static int atmel_spi_resume(struct platform_device *pdev) -{ - struct spi_master *master = platform_get_drvdata(pdev); - struct atmel_spi *as = spi_master_get_devdata(master); - - clk_enable(as->clk); - return 0; -} - -#else -#define atmel_spi_suspend NULL -#define atmel_spi_resume NULL -#endif - - -static struct platform_driver atmel_spi_driver = { - .driver = { - .name = "atmel_spi", - .owner = THIS_MODULE, - }, - .suspend = atmel_spi_suspend, - .resume = atmel_spi_resume, - .remove = __exit_p(atmel_spi_remove), -}; - -static int __init atmel_spi_init(void) -{ - return platform_driver_probe(&atmel_spi_driver, atmel_spi_probe); -} -module_init(atmel_spi_init); - -static void __exit atmel_spi_exit(void) -{ - platform_driver_unregister(&atmel_spi_driver); -} -module_exit(atmel_spi_exit); - -MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver"); -MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); -MODULE_LICENSE("GPL"); -MODULE_ALIAS("platform:atmel_spi"); |