diff options
Diffstat (limited to 'drivers/spi/dw_spi.c')
| -rw-r--r-- | drivers/spi/dw_spi.c | 988 |
1 files changed, 988 insertions, 0 deletions
diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c new file mode 100644 index 00000000..56247853 --- /dev/null +++ b/drivers/spi/dw_spi.c @@ -0,0 +1,988 @@ +/* + * dw_spi.c - Designware SPI core controller driver (refer pxa2xx_spi.c) + * + * Copyright (c) 2009, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions 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. + * + * 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/dma-mapping.h> +#include <linux/interrupt.h> +#include <linux/highmem.h> +#include <linux/delay.h> +#include <linux/slab.h> + +#include <linux/spi/dw_spi.h> +#include <linux/spi/spi.h> + +#ifdef CONFIG_DEBUG_FS +#include <linux/debugfs.h> +#endif + +#define START_STATE ((void *)0) +#define RUNNING_STATE ((void *)1) +#define DONE_STATE ((void *)2) +#define ERROR_STATE ((void *)-1) + +#define QUEUE_RUNNING 0 +#define QUEUE_STOPPED 1 + +#define MRST_SPI_DEASSERT 0 +#define MRST_SPI_ASSERT 1 + +/* Slave spi_dev related */ +struct chip_data { + u16 cr0; + u8 cs; /* chip select pin */ + u8 n_bytes; /* current is a 1/2/4 byte op */ + u8 tmode; /* TR/TO/RO/EEPROM */ + u8 type; /* SPI/SSP/MicroWire */ + + u8 poll_mode; /* 1 means use poll mode */ + + u32 dma_width; + u32 rx_threshold; + u32 tx_threshold; + u8 enable_dma; + u8 bits_per_word; + u16 clk_div; /* baud rate divider */ + u32 speed_hz; /* baud rate */ + int (*write)(struct dw_spi *dws); + int (*read)(struct dw_spi *dws); + void (*cs_control)(u32 command); +}; + +#ifdef CONFIG_DEBUG_FS +static int spi_show_regs_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + return 0; +} + +#define SPI_REGS_BUFSIZE 1024 +static ssize_t spi_show_regs(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct dw_spi *dws; + char *buf; + u32 len = 0; + ssize_t ret; + + dws = file->private_data; + + buf = kzalloc(SPI_REGS_BUFSIZE, GFP_KERNEL); + if (!buf) + return 0; + + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "MRST SPI0 registers:\n"); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "=================================\n"); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "CTRL0: \t\t0x%08x\n", dw_readl(dws, ctrl0)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "CTRL1: \t\t0x%08x\n", dw_readl(dws, ctrl1)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "SSIENR: \t0x%08x\n", dw_readl(dws, ssienr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "SER: \t\t0x%08x\n", dw_readl(dws, ser)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "BAUDR: \t\t0x%08x\n", dw_readl(dws, baudr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "TXFTLR: \t0x%08x\n", dw_readl(dws, txfltr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "RXFTLR: \t0x%08x\n", dw_readl(dws, rxfltr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "TXFLR: \t\t0x%08x\n", dw_readl(dws, txflr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "RXFLR: \t\t0x%08x\n", dw_readl(dws, rxflr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "SR: \t\t0x%08x\n", dw_readl(dws, sr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "IMR: \t\t0x%08x\n", dw_readl(dws, imr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "ISR: \t\t0x%08x\n", dw_readl(dws, isr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "DMACR: \t\t0x%08x\n", dw_readl(dws, dmacr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "DMATDLR: \t0x%08x\n", dw_readl(dws, dmatdlr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "DMARDLR: \t0x%08x\n", dw_readl(dws, dmardlr)); + len += snprintf(buf + len, SPI_REGS_BUFSIZE - len, + "=================================\n"); + + ret = simple_read_from_buffer(user_buf, count, ppos, buf, len); + kfree(buf); + return ret; +} + +static const struct file_operations mrst_spi_regs_ops = { + .owner = THIS_MODULE, + .open = spi_show_regs_open, + .read = spi_show_regs, +}; + +static int mrst_spi_debugfs_init(struct dw_spi *dws) +{ + dws->debugfs = debugfs_create_dir("mrst_spi", NULL); + if (!dws->debugfs) + return -ENOMEM; + + debugfs_create_file("registers", S_IFREG | S_IRUGO, + dws->debugfs, (void *)dws, &mrst_spi_regs_ops); + return 0; +} + +static void mrst_spi_debugfs_remove(struct dw_spi *dws) +{ + if (dws->debugfs) + debugfs_remove_recursive(dws->debugfs); +} + +#else +static inline int mrst_spi_debugfs_init(struct dw_spi *dws) +{ + return 0; +} + +static inline void mrst_spi_debugfs_remove(struct dw_spi *dws) +{ +} +#endif /* CONFIG_DEBUG_FS */ + +static void wait_till_not_busy(struct dw_spi *dws) +{ + unsigned long end = jiffies + 1 + usecs_to_jiffies(1000); + + while (time_before(jiffies, end)) { + if (!(dw_readw(dws, sr) & SR_BUSY)) + return; + } + dev_err(&dws->master->dev, + "DW SPI: Status keeps busy for 1000us after a read/write!\n"); +} + +static void flush(struct dw_spi *dws) +{ + while (dw_readw(dws, sr) & SR_RF_NOT_EMPT) + dw_readw(dws, dr); + + wait_till_not_busy(dws); +} + +static int null_writer(struct dw_spi *dws) +{ + u8 n_bytes = dws->n_bytes; + + if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL) + || (dws->tx == dws->tx_end)) + return 0; + dw_writew(dws, dr, 0); + dws->tx += n_bytes; + + wait_till_not_busy(dws); + return 1; +} + +static int null_reader(struct dw_spi *dws) +{ + u8 n_bytes = dws->n_bytes; + + while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT) + && (dws->rx < dws->rx_end)) { + dw_readw(dws, dr); + dws->rx += n_bytes; + } + wait_till_not_busy(dws); + return dws->rx == dws->rx_end; +} + +static int u8_writer(struct dw_spi *dws) +{ + if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL) + || (dws->tx == dws->tx_end)) + return 0; + + dw_writew(dws, dr, *(u8 *)(dws->tx)); + ++dws->tx; + + wait_till_not_busy(dws); + return 1; +} + +static int u8_reader(struct dw_spi *dws) +{ + while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT) + && (dws->rx < dws->rx_end)) { + *(u8 *)(dws->rx) = dw_readw(dws, dr); + ++dws->rx; + } + + wait_till_not_busy(dws); + return dws->rx == dws->rx_end; +} + +static int u16_writer(struct dw_spi *dws) +{ + if (!(dw_readw(dws, sr) & SR_TF_NOT_FULL) + || (dws->tx == dws->tx_end)) + return 0; + + dw_writew(dws, dr, *(u16 *)(dws->tx)); + dws->tx += 2; + + wait_till_not_busy(dws); + return 1; +} + +static int u16_reader(struct dw_spi *dws) +{ + u16 temp; + + while ((dw_readw(dws, sr) & SR_RF_NOT_EMPT) + && (dws->rx < dws->rx_end)) { + temp = dw_readw(dws, dr); + *(u16 *)(dws->rx) = temp; + dws->rx += 2; + } + + wait_till_not_busy(dws); + return dws->rx == dws->rx_end; +} + +static void *next_transfer(struct dw_spi *dws) +{ + struct spi_message *msg = dws->cur_msg; + struct spi_transfer *trans = dws->cur_transfer; + + /* Move to next transfer */ + if (trans->transfer_list.next != &msg->transfers) { + dws->cur_transfer = + list_entry(trans->transfer_list.next, + struct spi_transfer, + transfer_list); + return RUNNING_STATE; + } else + return DONE_STATE; +} + +/* + * Note: first step is the protocol driver prepares + * a dma-capable memory, and this func just need translate + * the virt addr to physical + */ +static int map_dma_buffers(struct dw_spi *dws) +{ + if (!dws->cur_msg->is_dma_mapped || !dws->dma_inited + || !dws->cur_chip->enable_dma) + return 0; + + if (dws->cur_transfer->tx_dma) + dws->tx_dma = dws->cur_transfer->tx_dma; + + if (dws->cur_transfer->rx_dma) + dws->rx_dma = dws->cur_transfer->rx_dma; + + return 1; +} + +/* Caller already set message->status; dma and pio irqs are blocked */ +static void giveback(struct dw_spi *dws) +{ + struct spi_transfer *last_transfer; + unsigned long flags; + struct spi_message *msg; + + spin_lock_irqsave(&dws->lock, flags); + msg = dws->cur_msg; + dws->cur_msg = NULL; + dws->cur_transfer = NULL; + dws->prev_chip = dws->cur_chip; + dws->cur_chip = NULL; + dws->dma_mapped = 0; + queue_work(dws->workqueue, &dws->pump_messages); + spin_unlock_irqrestore(&dws->lock, flags); + + last_transfer = list_entry(msg->transfers.prev, + struct spi_transfer, + transfer_list); + + if (!last_transfer->cs_change && dws->cs_control) + dws->cs_control(MRST_SPI_DEASSERT); + + msg->state = NULL; + if (msg->complete) + msg->complete(msg->context); +} + +static void int_error_stop(struct dw_spi *dws, const char *msg) +{ + /* Stop and reset hw */ + flush(dws); + spi_enable_chip(dws, 0); + + dev_err(&dws->master->dev, "%s\n", msg); + dws->cur_msg->state = ERROR_STATE; + tasklet_schedule(&dws->pump_transfers); +} + +static void transfer_complete(struct dw_spi *dws) +{ + /* Update total byte transfered return count actual bytes read */ + dws->cur_msg->actual_length += dws->len; + + /* Move to next transfer */ + dws->cur_msg->state = next_transfer(dws); + + /* Handle end of message */ + if (dws->cur_msg->state == DONE_STATE) { + dws->cur_msg->status = 0; + giveback(dws); + } else + tasklet_schedule(&dws->pump_transfers); +} + +static irqreturn_t interrupt_transfer(struct dw_spi *dws) +{ + u16 irq_status, irq_mask = 0x3f; + u32 int_level = dws->fifo_len / 2; + u32 left; + + irq_status = dw_readw(dws, isr) & irq_mask; + /* Error handling */ + if (irq_status & (SPI_INT_TXOI | SPI_INT_RXOI | SPI_INT_RXUI)) { + dw_readw(dws, txoicr); + dw_readw(dws, rxoicr); + dw_readw(dws, rxuicr); + int_error_stop(dws, "interrupt_transfer: fifo overrun"); + return IRQ_HANDLED; + } + + if (irq_status & SPI_INT_TXEI) { + spi_mask_intr(dws, SPI_INT_TXEI); + + left = (dws->tx_end - dws->tx) / dws->n_bytes; + left = (left > int_level) ? int_level : left; + + while (left--) + dws->write(dws); + dws->read(dws); + + /* Re-enable the IRQ if there is still data left to tx */ + if (dws->tx_end > dws->tx) + spi_umask_intr(dws, SPI_INT_TXEI); + else + transfer_complete(dws); + } + + return IRQ_HANDLED; +} + +static irqreturn_t dw_spi_irq(int irq, void *dev_id) +{ + struct dw_spi *dws = dev_id; + u16 irq_status, irq_mask = 0x3f; + + irq_status = dw_readw(dws, isr) & irq_mask; + if (!irq_status) + return IRQ_NONE; + + if (!dws->cur_msg) { + spi_mask_intr(dws, SPI_INT_TXEI); + /* Never fail */ + return IRQ_HANDLED; + } + + return dws->transfer_handler(dws); +} + +/* Must be called inside pump_transfers() */ +static void poll_transfer(struct dw_spi *dws) +{ + while (dws->write(dws)) + dws->read(dws); + + transfer_complete(dws); +} + +static void dma_transfer(struct dw_spi *dws, int cs_change) +{ +} + +static void pump_transfers(unsigned long data) +{ + struct dw_spi *dws = (struct dw_spi *)data; + struct spi_message *message = NULL; + struct spi_transfer *transfer = NULL; + struct spi_transfer *previous = NULL; + struct spi_device *spi = NULL; + struct chip_data *chip = NULL; + u8 bits = 0; + u8 imask = 0; + u8 cs_change = 0; + u16 txint_level = 0; + u16 clk_div = 0; + u32 speed = 0; + u32 cr0 = 0; + + /* Get current state information */ + message = dws->cur_msg; + transfer = dws->cur_transfer; + chip = dws->cur_chip; + spi = message->spi; + + if (unlikely(!chip->clk_div)) + chip->clk_div = dws->max_freq / chip->speed_hz; + + if (message->state == ERROR_STATE) { + message->status = -EIO; + goto early_exit; + } + + /* Handle end of message */ + if (message->state == DONE_STATE) { + message->status = 0; + goto early_exit; + } + + /* Delay if requested at end of transfer*/ + if (message->state == RUNNING_STATE) { + previous = list_entry(transfer->transfer_list.prev, + struct spi_transfer, + transfer_list); + if (previous->delay_usecs) + udelay(previous->delay_usecs); + } + + dws->n_bytes = chip->n_bytes; + dws->dma_width = chip->dma_width; + dws->cs_control = chip->cs_control; + + dws->rx_dma = transfer->rx_dma; + dws->tx_dma = transfer->tx_dma; + dws->tx = (void *)transfer->tx_buf; + dws->tx_end = dws->tx + transfer->len; + dws->rx = transfer->rx_buf; + dws->rx_end = dws->rx + transfer->len; + dws->write = dws->tx ? chip->write : null_writer; + dws->read = dws->rx ? chip->read : null_reader; + dws->cs_change = transfer->cs_change; + dws->len = dws->cur_transfer->len; + if (chip != dws->prev_chip) + cs_change = 1; + + cr0 = chip->cr0; + + /* Handle per transfer options for bpw and speed */ + if (transfer->speed_hz) { + speed = chip->speed_hz; + + if (transfer->speed_hz != speed) { + speed = transfer->speed_hz; + if (speed > dws->max_freq) { + printk(KERN_ERR "MRST SPI0: unsupported" + "freq: %dHz\n", speed); + message->status = -EIO; + goto early_exit; + } + + /* clk_div doesn't support odd number */ + clk_div = dws->max_freq / speed; + clk_div = (clk_div + 1) & 0xfffe; + + chip->speed_hz = speed; + chip->clk_div = clk_div; + } + } + if (transfer->bits_per_word) { + bits = transfer->bits_per_word; + + switch (bits) { + case 8: + dws->n_bytes = 1; + dws->dma_width = 1; + dws->read = (dws->read != null_reader) ? + u8_reader : null_reader; + dws->write = (dws->write != null_writer) ? + u8_writer : null_writer; + break; + case 16: + dws->n_bytes = 2; + dws->dma_width = 2; + dws->read = (dws->read != null_reader) ? + u16_reader : null_reader; + dws->write = (dws->write != null_writer) ? + u16_writer : null_writer; + break; + default: + printk(KERN_ERR "MRST SPI0: unsupported bits:" + "%db\n", bits); + message->status = -EIO; + goto early_exit; + } + + cr0 = (bits - 1) + | (chip->type << SPI_FRF_OFFSET) + | (spi->mode << SPI_MODE_OFFSET) + | (chip->tmode << SPI_TMOD_OFFSET); + } + message->state = RUNNING_STATE; + + /* + * Adjust transfer mode if necessary. Requires platform dependent + * chipselect mechanism. + */ + if (dws->cs_control) { + if (dws->rx && dws->tx) + chip->tmode = SPI_TMOD_TR; + else if (dws->rx) + chip->tmode = SPI_TMOD_RO; + else + chip->tmode = SPI_TMOD_TO; + + cr0 &= ~SPI_TMOD_MASK; + cr0 |= (chip->tmode << SPI_TMOD_OFFSET); + } + + /* Check if current transfer is a DMA transaction */ + dws->dma_mapped = map_dma_buffers(dws); + + /* + * Interrupt mode + * we only need set the TXEI IRQ, as TX/RX always happen syncronizely + */ + if (!dws->dma_mapped && !chip->poll_mode) { + int templen = dws->len / dws->n_bytes; + txint_level = dws->fifo_len / 2; + txint_level = (templen > txint_level) ? txint_level : templen; + + imask |= SPI_INT_TXEI; + dws->transfer_handler = interrupt_transfer; + } + + /* + * Reprogram registers only if + * 1. chip select changes + * 2. clk_div is changed + * 3. control value changes + */ + if (dw_readw(dws, ctrl0) != cr0 || cs_change || clk_div || imask) { + spi_enable_chip(dws, 0); + + if (dw_readw(dws, ctrl0) != cr0) + dw_writew(dws, ctrl0, cr0); + + spi_set_clk(dws, clk_div ? clk_div : chip->clk_div); + spi_chip_sel(dws, spi->chip_select); + + /* Set the interrupt mask, for poll mode just diable all int */ + spi_mask_intr(dws, 0xff); + if (imask) + spi_umask_intr(dws, imask); + if (txint_level) + dw_writew(dws, txfltr, txint_level); + + spi_enable_chip(dws, 1); + if (cs_change) + dws->prev_chip = chip; + } + + if (dws->dma_mapped) + dma_transfer(dws, cs_change); + + if (chip->poll_mode) + poll_transfer(dws); + + return; + +early_exit: + giveback(dws); + return; +} + +static void pump_messages(struct work_struct *work) +{ + struct dw_spi *dws = + container_of(work, struct dw_spi, pump_messages); + unsigned long flags; + + /* Lock queue and check for queue work */ + spin_lock_irqsave(&dws->lock, flags); + if (list_empty(&dws->queue) || dws->run == QUEUE_STOPPED) { + dws->busy = 0; + spin_unlock_irqrestore(&dws->lock, flags); + return; + } + + /* Make sure we are not already running a message */ + if (dws->cur_msg) { + spin_unlock_irqrestore(&dws->lock, flags); + return; + } + + /* Extract head of queue */ + dws->cur_msg = list_entry(dws->queue.next, struct spi_message, queue); + list_del_init(&dws->cur_msg->queue); + + /* Initial message state*/ + dws->cur_msg->state = START_STATE; + dws->cur_transfer = list_entry(dws->cur_msg->transfers.next, + struct spi_transfer, + transfer_list); + dws->cur_chip = spi_get_ctldata(dws->cur_msg->spi); + + /* Mark as busy and launch transfers */ + tasklet_schedule(&dws->pump_transfers); + + dws->busy = 1; + spin_unlock_irqrestore(&dws->lock, flags); +} + +/* spi_device use this to queue in their spi_msg */ +static int dw_spi_transfer(struct spi_device *spi, struct spi_message *msg) +{ + struct dw_spi *dws = spi_master_get_devdata(spi->master); + unsigned long flags; + + spin_lock_irqsave(&dws->lock, flags); + + if (dws->run == QUEUE_STOPPED) { + spin_unlock_irqrestore(&dws->lock, flags); + return -ESHUTDOWN; + } + + msg->actual_length = 0; + msg->status = -EINPROGRESS; + msg->state = START_STATE; + + list_add_tail(&msg->queue, &dws->queue); + + if (dws->run == QUEUE_RUNNING && !dws->busy) { + + if (dws->cur_transfer || dws->cur_msg) + queue_work(dws->workqueue, + &dws->pump_messages); + else { + /* If no other data transaction in air, just go */ + spin_unlock_irqrestore(&dws->lock, flags); + pump_messages(&dws->pump_messages); + return 0; + } + } + + spin_unlock_irqrestore(&dws->lock, flags); + return 0; +} + +/* This may be called twice for each spi dev */ +static int dw_spi_setup(struct spi_device *spi) +{ + struct dw_spi_chip *chip_info = NULL; + struct chip_data *chip; + + if (spi->bits_per_word != 8 && spi->bits_per_word != 16) + return -EINVAL; + + /* Only alloc on first setup */ + chip = spi_get_ctldata(spi); + if (!chip) { + chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); + if (!chip) + return -ENOMEM; + } + + /* + * Protocol drivers may change the chip settings, so... + * if chip_info exists, use it + */ + chip_info = spi->controller_data; + + /* chip_info doesn't always exist */ + if (chip_info) { + if (chip_info->cs_control) + chip->cs_control = chip_info->cs_control; + + chip->poll_mode = chip_info->poll_mode; + chip->type = chip_info->type; + + chip->rx_threshold = 0; + chip->tx_threshold = 0; + + chip->enable_dma = chip_info->enable_dma; + } + + if (spi->bits_per_word <= 8) { + chip->n_bytes = 1; + chip->dma_width = 1; + chip->read = u8_reader; + chip->write = u8_writer; + } else if (spi->bits_per_word <= 16) { + chip->n_bytes = 2; + chip->dma_width = 2; + chip->read = u16_reader; + chip->write = u16_writer; + } else { + /* Never take >16b case for MRST SPIC */ + dev_err(&spi->dev, "invalid wordsize\n"); + return -EINVAL; + } + chip->bits_per_word = spi->bits_per_word; + + if (!spi->max_speed_hz) { + dev_err(&spi->dev, "No max speed HZ parameter\n"); + return -EINVAL; + } + chip->speed_hz = spi->max_speed_hz; + + chip->tmode = 0; /* Tx & Rx */ + /* Default SPI mode is SCPOL = 0, SCPH = 0 */ + chip->cr0 = (chip->bits_per_word - 1) + | (chip->type << SPI_FRF_OFFSET) + | (spi->mode << SPI_MODE_OFFSET) + | (chip->tmode << SPI_TMOD_OFFSET); + + spi_set_ctldata(spi, chip); + return 0; +} + +static void dw_spi_cleanup(struct spi_device *spi) +{ + struct chip_data *chip = spi_get_ctldata(spi); + kfree(chip); +} + +static int __devinit init_queue(struct dw_spi *dws) +{ + INIT_LIST_HEAD(&dws->queue); + spin_lock_init(&dws->lock); + + dws->run = QUEUE_STOPPED; + dws->busy = 0; + + tasklet_init(&dws->pump_transfers, + pump_transfers, (unsigned long)dws); + + INIT_WORK(&dws->pump_messages, pump_messages); + dws->workqueue = create_singlethread_workqueue( + dev_name(dws->master->dev.parent)); + if (dws->workqueue == NULL) + return -EBUSY; + + return 0; +} + +static int start_queue(struct dw_spi *dws) +{ + unsigned long flags; + + spin_lock_irqsave(&dws->lock, flags); + + if (dws->run == QUEUE_RUNNING || dws->busy) { + spin_unlock_irqrestore(&dws->lock, flags); + return -EBUSY; + } + + dws->run = QUEUE_RUNNING; + dws->cur_msg = NULL; + dws->cur_transfer = NULL; + dws->cur_chip = NULL; + dws->prev_chip = NULL; + spin_unlock_irqrestore(&dws->lock, flags); + + queue_work(dws->workqueue, &dws->pump_messages); + + return 0; +} + +static int stop_queue(struct dw_spi *dws) +{ + unsigned long flags; + unsigned limit = 50; + int status = 0; + + spin_lock_irqsave(&dws->lock, flags); + dws->run = QUEUE_STOPPED; + while (!list_empty(&dws->queue) && dws->busy && limit--) { + spin_unlock_irqrestore(&dws->lock, flags); + msleep(10); + spin_lock_irqsave(&dws->lock, flags); + } + + if (!list_empty(&dws->queue) || dws->busy) + status = -EBUSY; + spin_unlock_irqrestore(&dws->lock, flags); + + return status; +} + +static int destroy_queue(struct dw_spi *dws) +{ + int status; + + status = stop_queue(dws); + if (status != 0) + return status; + destroy_workqueue(dws->workqueue); + return 0; +} + +/* Restart the controller, disable all interrupts, clean rx fifo */ +static void spi_hw_init(struct dw_spi *dws) +{ + spi_enable_chip(dws, 0); + spi_mask_intr(dws, 0xff); + spi_enable_chip(dws, 1); + flush(dws); + + /* + * Try to detect the FIFO depth if not set by interface driver, + * the depth could be from 2 to 256 from HW spec + */ + if (!dws->fifo_len) { + u32 fifo; + for (fifo = 2; fifo <= 257; fifo++) { + dw_writew(dws, txfltr, fifo); + if (fifo != dw_readw(dws, txfltr)) + break; + } + + dws->fifo_len = (fifo == 257) ? 0 : fifo; + dw_writew(dws, txfltr, 0); + } +} + +int __devinit dw_spi_add_host(struct dw_spi *dws) +{ + struct spi_master *master; + int ret; + + BUG_ON(dws == NULL); + + master = spi_alloc_master(dws->parent_dev, 0); + if (!master) { + ret = -ENOMEM; + goto exit; + } + + dws->master = master; + dws->type = SSI_MOTO_SPI; + dws->prev_chip = NULL; + dws->dma_inited = 0; + dws->dma_addr = (dma_addr_t)(dws->paddr + 0x60); + + ret = request_irq(dws->irq, dw_spi_irq, IRQF_SHARED, + "dw_spi", dws); + if (ret < 0) { + dev_err(&master->dev, "can not get IRQ\n"); + goto err_free_master; + } + + master->mode_bits = SPI_CPOL | SPI_CPHA; + master->bus_num = dws->bus_num; + master->num_chipselect = dws->num_cs; + master->cleanup = dw_spi_cleanup; + master->setup = dw_spi_setup; + master->transfer = dw_spi_transfer; + + dws->dma_inited = 0; + + /* Basic HW init */ + spi_hw_init(dws); + + /* Initial and start queue */ + ret = init_queue(dws); + if (ret) { + dev_err(&master->dev, "problem initializing queue\n"); + goto err_diable_hw; + } + ret = start_queue(dws); + if (ret) { + dev_err(&master->dev, "problem starting queue\n"); + goto err_diable_hw; + } + + spi_master_set_devdata(master, dws); + ret = spi_register_master(master); + if (ret) { + dev_err(&master->dev, "problem registering spi master\n"); + goto err_queue_alloc; + } + + mrst_spi_debugfs_init(dws); + return 0; + +err_queue_alloc: + destroy_queue(dws); +err_diable_hw: + spi_enable_chip(dws, 0); + free_irq(dws->irq, dws); +err_free_master: + spi_master_put(master); +exit: + return ret; +} +EXPORT_SYMBOL(dw_spi_add_host); + +void __devexit dw_spi_remove_host(struct dw_spi *dws) +{ + int status = 0; + + if (!dws) + return; + mrst_spi_debugfs_remove(dws); + + /* Remove the queue */ + status = destroy_queue(dws); + if (status != 0) + dev_err(&dws->master->dev, "dw_spi_remove: workqueue will not " + "complete, message memory not freed\n"); + + spi_enable_chip(dws, 0); + /* Disable clk */ + spi_set_clk(dws, 0); + free_irq(dws->irq, dws); + + /* Disconnect from the SPI framework */ + spi_unregister_master(dws->master); +} +EXPORT_SYMBOL(dw_spi_remove_host); + +int dw_spi_suspend_host(struct dw_spi *dws) +{ + int ret = 0; + + ret = stop_queue(dws); + if (ret) + return ret; + spi_enable_chip(dws, 0); + spi_set_clk(dws, 0); + return ret; +} +EXPORT_SYMBOL(dw_spi_suspend_host); + +int dw_spi_resume_host(struct dw_spi *dws) +{ + int ret; + + spi_hw_init(dws); + ret = start_queue(dws); + if (ret) + dev_err(&dws->master->dev, "fail to start queue (%d)\n", ret); + return ret; +} +EXPORT_SYMBOL(dw_spi_resume_host); + +MODULE_AUTHOR("Feng Tang <feng.tang@intel.com>"); +MODULE_DESCRIPTION("Driver for DesignWare SPI controller core"); +MODULE_LICENSE("GPL v2"); |