diff options
Diffstat (limited to 'drivers/spi/spi_bfin5xx.c')
| -rw-r--r-- | drivers/spi/spi_bfin5xx.c | 1313 |
1 files changed, 1313 insertions, 0 deletions
diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c new file mode 100644 index 000000000000..ce3c0ce2316e --- /dev/null +++ b/drivers/spi/spi_bfin5xx.c @@ -0,0 +1,1313 @@ +/* + * File: drivers/spi/bfin5xx_spi.c + * Based on: N/A + * Author: Luke Yang (Analog Devices Inc.) + * + * Created: March. 10th 2006 + * Description: SPI controller driver for Blackfin 5xx + * Bugs: Enter bugs at http://blackfin.uclinux.org/ + * + * Modified: + * March 10, 2006 bfin5xx_spi.c Created. (Luke Yang) + * August 7, 2006 added full duplex mode (Axel Weiss & Luke Yang) + * + * Copyright 2004-2006 Analog Devices Inc. + * + * 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 ; either version 2, or (at your option) + * any later version. + * + * 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 ; see the file COPYING. + * If not, write to the Free Software Foundation, + * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/ioport.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/platform_device.h> +#include <linux/dma-mapping.h> +#include <linux/spi/spi.h> +#include <linux/workqueue.h> +#include <linux/errno.h> +#include <linux/delay.h> + +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/delay.h> +#include <asm/dma.h> + +#include <asm/bfin5xx_spi.h> + +MODULE_AUTHOR("Luke Yang"); +MODULE_DESCRIPTION("Blackfin 5xx SPI Contoller"); +MODULE_LICENSE("GPL"); + +#define IS_DMA_ALIGNED(x) (((u32)(x)&0x07)==0) + +#define DEFINE_SPI_REG(reg, off) \ +static inline u16 read_##reg(void) \ + { return *(volatile unsigned short*)(SPI0_REGBASE + off); } \ +static inline void write_##reg(u16 v) \ + {*(volatile unsigned short*)(SPI0_REGBASE + off) = v;\ + SSYNC();} + +DEFINE_SPI_REG(CTRL, 0x00) +DEFINE_SPI_REG(FLAG, 0x04) +DEFINE_SPI_REG(STAT, 0x08) +DEFINE_SPI_REG(TDBR, 0x0C) +DEFINE_SPI_REG(RDBR, 0x10) +DEFINE_SPI_REG(BAUD, 0x14) +DEFINE_SPI_REG(SHAW, 0x18) +#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 +int dma_requested; + +struct driver_data { + /* Driver model hookup */ + struct platform_device *pdev; + + /* SPI framework hookup */ + struct spi_master *master; + + /* BFIN hookup */ + struct bfin5xx_spi_master *master_info; + + /* Driver message queue */ + struct workqueue_struct *workqueue; + struct work_struct pump_messages; + spinlock_t lock; + struct list_head queue; + int busy; + int run; + + /* Message Transfer pump */ + struct tasklet_struct pump_transfers; + + /* Current message transfer state info */ + struct spi_message *cur_msg; + struct spi_transfer *cur_transfer; + struct chip_data *cur_chip; + size_t len_in_bytes; + size_t len; + void *tx; + void *tx_end; + void *rx; + void *rx_end; + int dma_mapped; + dma_addr_t rx_dma; + dma_addr_t tx_dma; + size_t rx_map_len; + size_t tx_map_len; + u8 n_bytes; + void (*write) (struct driver_data *); + void (*read) (struct driver_data *); + void (*duplex) (struct driver_data *); +}; + +struct chip_data { + u16 ctl_reg; + u16 baud; + u16 flag; + + u8 chip_select_num; + u8 n_bytes; + u32 width; /* 0 or 1 */ + u8 enable_dma; + u8 bits_per_word; /* 8 or 16 */ + u8 cs_change_per_word; + u8 cs_chg_udelay; + void (*write) (struct driver_data *); + void (*read) (struct driver_data *); + void (*duplex) (struct driver_data *); +}; + +void bfin_spi_enable(struct driver_data *drv_data) +{ + u16 cr; + + cr = read_CTRL(); + write_CTRL(cr | BIT_CTL_ENABLE); + SSYNC(); +} + +void bfin_spi_disable(struct driver_data *drv_data) +{ + u16 cr; + + cr = read_CTRL(); + write_CTRL(cr & (~BIT_CTL_ENABLE)); + SSYNC(); +} + +/* Caculate the SPI_BAUD register value based on input HZ */ +static u16 hz_to_spi_baud(u32 speed_hz) +{ + u_long sclk = get_sclk(); + u16 spi_baud = (sclk / (2 * speed_hz)); + + if ((sclk % (2 * speed_hz)) > 0) + spi_baud++; + + pr_debug("sclk = %ld, speed_hz = %d, spi_baud = %d\n", sclk, speed_hz, + spi_baud); + + return spi_baud; +} + +static int flush(struct driver_data *drv_data) +{ + unsigned long limit = loops_per_jiffy << 1; + + /* wait for stop and clear stat */ + while (!(read_STAT() & BIT_STAT_SPIF) && limit--) + continue; + + write_STAT(BIT_STAT_CLR); + + return limit; +} + +/* stop controller and re-config current chip*/ +static void restore_state(struct driver_data *drv_data) +{ + struct chip_data *chip = drv_data->cur_chip; + + /* Clear status and disable clock */ + write_STAT(BIT_STAT_CLR); + bfin_spi_disable(drv_data); + pr_debug("restoring spi ctl state\n"); + +#if defined(CONFIG_BF534) || defined(CONFIG_BF536) || defined(CONFIG_BF537) + pr_debug("chip select number is %d\n", chip->chip_select_num); + + switch (chip->chip_select_num) { + case 1: + bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3c00); + SSYNC(); + break; + + case 2: + case 3: + bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJSE_SPI); + SSYNC(); + bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800); + SSYNC(); + break; + + case 4: + bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS4E_SPI); + SSYNC(); + bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3840); + SSYNC(); + break; + + case 5: + bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS5E_SPI); + SSYNC(); + bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3820); + SSYNC(); + break; + + case 6: + bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PFS6E_SPI); + SSYNC(); + bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3810); + SSYNC(); + break; + + case 7: + bfin_write_PORT_MUX(bfin_read_PORT_MUX() | PJCE_SPI); + SSYNC(); + bfin_write_PORTF_FER(bfin_read_PORTF_FER() | 0x3800); + SSYNC(); + break; + } +#endif + + /* Load the registers */ + write_CTRL(chip->ctl_reg); + write_BAUD(chip->baud); + write_FLAG(chip->flag); +} + +/* used to kick off transfer in rx mode */ +static unsigned short dummy_read(void) +{ + unsigned short tmp; + tmp = read_RDBR(); + return tmp; +} + +static void null_writer(struct driver_data *drv_data) +{ + u8 n_bytes = drv_data->n_bytes; + + while (drv_data->tx < drv_data->tx_end) { + write_TDBR(0); + while ((read_STAT() & BIT_STAT_TXS)) + continue; + drv_data->tx += n_bytes; + } +} + +static void null_reader(struct driver_data *drv_data) +{ + u8 n_bytes = drv_data->n_bytes; + dummy_read(); + + while (drv_data->rx < drv_data->rx_end) { + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + dummy_read(); + drv_data->rx += n_bytes; + } +} + +static void u8_writer(struct driver_data *drv_data) +{ + pr_debug("cr8-s is 0x%x\n", read_STAT()); + while (drv_data->tx < drv_data->tx_end) { + write_TDBR(*(u8 *) (drv_data->tx)); + while (read_STAT() & BIT_STAT_TXS) + continue; + ++drv_data->tx; + } + + /* poll for SPI completion before returning */ + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; +} + +static void u8_cs_chg_writer(struct driver_data *drv_data) +{ + struct chip_data *chip = drv_data->cur_chip; + + while (drv_data->tx < drv_data->tx_end) { + write_FLAG(chip->flag); + SSYNC(); + + write_TDBR(*(u8 *) (drv_data->tx)); + while (read_STAT() & BIT_STAT_TXS) + continue; + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; + write_FLAG(0xFF00 | chip->flag); + SSYNC(); + if (chip->cs_chg_udelay) + udelay(chip->cs_chg_udelay); + ++drv_data->tx; + } + write_FLAG(0xFF00); + SSYNC(); +} + +static void u8_reader(struct driver_data *drv_data) +{ + pr_debug("cr-8 is 0x%x\n", read_STAT()); + + /* clear TDBR buffer before read(else it will be shifted out) */ + write_TDBR(0xFFFF); + + dummy_read(); + + while (drv_data->rx < drv_data->rx_end - 1) { + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + *(u8 *) (drv_data->rx) = read_RDBR(); + ++drv_data->rx; + } + + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + *(u8 *) (drv_data->rx) = read_SHAW(); + ++drv_data->rx; +} + +static void u8_cs_chg_reader(struct driver_data *drv_data) +{ + struct chip_data *chip = drv_data->cur_chip; + + while (drv_data->rx < drv_data->rx_end) { + write_FLAG(chip->flag); + SSYNC(); + + read_RDBR(); /* kick off */ + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; + *(u8 *) (drv_data->rx) = read_SHAW(); + write_FLAG(0xFF00 | chip->flag); + SSYNC(); + if (chip->cs_chg_udelay) + udelay(chip->cs_chg_udelay); + ++drv_data->rx; + } + write_FLAG(0xFF00); + SSYNC(); +} + +static void u8_duplex(struct driver_data *drv_data) +{ + /* in duplex mode, clk is triggered by writing of TDBR */ + while (drv_data->rx < drv_data->rx_end) { + write_TDBR(*(u8 *) (drv_data->tx)); + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + *(u8 *) (drv_data->rx) = read_RDBR(); + ++drv_data->rx; + ++drv_data->tx; + } +} + +static void u8_cs_chg_duplex(struct driver_data *drv_data) +{ + struct chip_data *chip = drv_data->cur_chip; + + while (drv_data->rx < drv_data->rx_end) { + write_FLAG(chip->flag); + SSYNC(); + + write_TDBR(*(u8 *) (drv_data->tx)); + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + *(u8 *) (drv_data->rx) = read_RDBR(); + write_FLAG(0xFF00 | chip->flag); + SSYNC(); + if (chip->cs_chg_udelay) + udelay(chip->cs_chg_udelay); + ++drv_data->rx; + ++drv_data->tx; + } + write_FLAG(0xFF00); + SSYNC(); +} + +static void u16_writer(struct driver_data *drv_data) +{ + pr_debug("cr16 is 0x%x\n", read_STAT()); + while (drv_data->tx < drv_data->tx_end) { + write_TDBR(*(u16 *) (drv_data->tx)); + while ((read_STAT() & BIT_STAT_TXS)) + continue; + drv_data->tx += 2; + } + + /* poll for SPI completion before returning */ + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; +} + +static void u16_cs_chg_writer(struct driver_data *drv_data) +{ + struct chip_data *chip = drv_data->cur_chip; + + while (drv_data->tx < drv_data->tx_end) { + write_FLAG(chip->flag); + SSYNC(); + + write_TDBR(*(u16 *) (drv_data->tx)); + while ((read_STAT() & BIT_STAT_TXS)) + continue; + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; + write_FLAG(0xFF00 | chip->flag); + SSYNC(); + if (chip->cs_chg_udelay) + udelay(chip->cs_chg_udelay); + drv_data->tx += 2; + } + write_FLAG(0xFF00); + SSYNC(); +} + +static void u16_reader(struct driver_data *drv_data) +{ + pr_debug("cr-16 is 0x%x\n", read_STAT()); + dummy_read(); + + while (drv_data->rx < (drv_data->rx_end - 2)) { + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + *(u16 *) (drv_data->rx) = read_RDBR(); + drv_data->rx += 2; + } + + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + *(u16 *) (drv_data->rx) = read_SHAW(); + drv_data->rx += 2; +} + +static void u16_cs_chg_reader(struct driver_data *drv_data) +{ + struct chip_data *chip = drv_data->cur_chip; + + while (drv_data->rx < drv_data->rx_end) { + write_FLAG(chip->flag); + SSYNC(); + + read_RDBR(); /* kick off */ + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; + *(u16 *) (drv_data->rx) = read_SHAW(); + write_FLAG(0xFF00 | chip->flag); + SSYNC(); + if (chip->cs_chg_udelay) + udelay(chip->cs_chg_udelay); + drv_data->rx += 2; + } + write_FLAG(0xFF00); + SSYNC(); +} + +static void u16_duplex(struct driver_data *drv_data) +{ + /* in duplex mode, clk is triggered by writing of TDBR */ + while (drv_data->tx < drv_data->tx_end) { + write_TDBR(*(u16 *) (drv_data->tx)); + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + *(u16 *) (drv_data->rx) = read_RDBR(); + drv_data->rx += 2; + drv_data->tx += 2; + } +} + +static void u16_cs_chg_duplex(struct driver_data *drv_data) +{ + struct chip_data *chip = drv_data->cur_chip; + + while (drv_data->tx < drv_data->tx_end) { + write_FLAG(chip->flag); + SSYNC(); + + write_TDBR(*(u16 *) (drv_data->tx)); + while (!(read_STAT() & BIT_STAT_SPIF)) + continue; + while (!(read_STAT() & BIT_STAT_RXS)) + continue; + *(u16 *) (drv_data->rx) = read_RDBR(); + write_FLAG(0xFF00 | chip->flag); + SSYNC(); + if (chip->cs_chg_udelay) + udelay(chip->cs_chg_udelay); + drv_data->rx += 2; + drv_data->tx += 2; + } + write_FLAG(0xFF00); + SSYNC(); +} + +/* test if ther is more transfer to be done */ +static void *next_transfer(struct driver_data *drv_data) +{ + struct spi_message *msg = drv_data->cur_msg; + struct spi_transfer *trans = drv_data->cur_transfer; + + /* Move to next transfer */ + if (trans->transfer_list.next != &msg->transfers) { + drv_data->cur_transfer = + list_entry(trans->transfer_list.next, + struct spi_transfer, transfer_list); + return RUNNING_STATE; + } else + return DONE_STATE; +} + +/* + * caller already set message->status; + * dma and pio irqs are blocked give finished message back + */ +static void giveback(struct driver_data *drv_data) +{ + struct spi_transfer *last_transfer; + unsigned long flags; + struct spi_message *msg; + + spin_lock_irqsave(&drv_data->lock, flags); + msg = drv_data->cur_msg; + drv_data->cur_msg = NULL; + drv_data->cur_transfer = NULL; + drv_data->cur_chip = NULL; + queue_work(drv_data->workqueue, &drv_data->pump_messages); + spin_unlock_irqrestore(&drv_data->lock, flags); + + last_transfer = list_entry(msg->transfers.prev, + struct spi_transfer, transfer_list); + + msg->state = NULL; + + /* disable chip select signal. And not stop spi in autobuffer mode */ + if (drv_data->tx_dma != 0xFFFF) { + write_FLAG(0xFF00); + bfin_spi_disable(drv_data); + } + + if (msg->complete) + msg->complete(msg->context); +} + +static irqreturn_t dma_irq_handler(int irq, void *dev_id, struct pt_regs *regs) +{ + struct driver_data *drv_data = (struct driver_data *)dev_id; + struct spi_message *msg = drv_data->cur_msg; + + pr_debug("in dma_irq_handler\n"); + clear_dma_irqstat(CH_SPI); + + /* + * wait for the last transaction shifted out. yes, these two + * while loops are supposed to be the same (see the HRM). + */ + if (drv_data->tx != NULL) { + while (bfin_read_SPI_STAT() & TXS) + continue; + while (bfin_read_SPI_STAT() & TXS) + continue; + } + + while (!(bfin_read_SPI_STAT() & SPIF)) + continue; + + bfin_spi_disable(drv_data); + + msg->actual_length += drv_data->len_in_bytes; + + /* Move to next transfer */ + msg->state = next_transfer(drv_data); + + /* Schedule transfer tasklet */ + tasklet_schedule(&drv_data->pump_transfers); + + /* free the irq handler before next transfer */ + pr_debug("disable dma channel irq%d\n", CH_SPI); + dma_disable_irq(CH_SPI); + + return IRQ_HANDLED; +} + +static void pump_transfers(unsigned long data) +{ + struct driver_data *drv_data = (struct driver_data *)data; + struct spi_message *message = NULL; + struct spi_transfer *transfer = NULL; + struct spi_transfer *previous = NULL; + struct chip_data *chip = NULL; + u16 cr, width, dma_width, dma_config; + u32 tranf_success = 1; + + /* Get current state information */ + message = drv_data->cur_msg; + transfer = drv_data->cur_transfer; + chip = drv_data->cur_chip; + + /* + * if msg is error or done, report it back using complete() callback + */ + + /* Handle for abort */ + if (message->state == ERROR_STATE) { + message->status = -EIO; + giveback(drv_data); + return; + } + + /* Handle end of message */ + if (message->state == DONE_STATE) { + message->status = 0; + giveback(drv_data); + return; + } + + /* 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); + } + + /* Setup the transfer state based on the type of transfer */ + if (flush(drv_data) == 0) { + dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n"); + message->status = -EIO; + giveback(drv_data); + return; + } + + if (transfer->tx_buf != NULL) { + drv_data->tx = (void *)transfer->tx_buf; + drv_data->tx_end = drv_data->tx + transfer->len; + pr_debug("tx_buf is %p, tx_end is %p\n", transfer->tx_buf, + drv_data->tx_end); + } else { + drv_data->tx = NULL; + } + + if (transfer->rx_buf != NULL) { + drv_data->rx = transfer->rx_buf; + drv_data->rx_end = drv_data->rx + transfer->len; + pr_debug("rx_buf is %p, rx_end is %p\n", transfer->rx_buf, + drv_data->rx_end); + } else { + drv_data->rx = NULL; + } + + drv_data->rx_dma = transfer->rx_dma; + drv_data->tx_dma = transfer->tx_dma; + drv_data->len_in_bytes = transfer->len; + + width = chip->width; + if (width == CFG_SPI_WORDSIZE16) { + drv_data->len = (transfer->len) >> 1; + } else { + drv_data->len = transfer->len; + } + drv_data->write = drv_data->tx ? chip->write : null_writer; + drv_data->read = drv_data->rx ? chip->read : null_reader; + drv_data->duplex = chip->duplex ? chip->duplex : null_writer; + pr_debug + ("transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n", + drv_data->write, chip->write, null_writer); + + /* speed and width has been set on per message */ + message->state = RUNNING_STATE; + dma_config = 0; + + /* restore spi status for each spi transfer */ + if (transfer->speed_hz) { + write_BAUD(hz_to_spi_baud(transfer->speed_hz)); + } else { + write_BAUD(chip->baud); + } + write_FLAG(chip->flag); + + pr_debug("now pumping a transfer: width is %d, len is %d\n", width, + transfer->len); + + /* + * Try to map dma buffer and do a dma transfer if + * successful use different way to r/w according to + * drv_data->cur_chip->enable_dma + */ + if (drv_data->cur_chip->enable_dma && drv_data->len > 6) { + + write_STAT(BIT_STAT_CLR); + disable_dma(CH_SPI); + clear_dma_irqstat(CH_SPI); + bfin_spi_disable(drv_data); + + /* config dma channel */ + pr_debug("doing dma transfer\n"); + if (width == CFG_SPI_WORDSIZE16) { + set_dma_x_count(CH_SPI, drv_data->len); + set_dma_x_modify(CH_SPI, 2); + dma_width = WDSIZE_16; + } else { + set_dma_x_count(CH_SPI, drv_data->len); + set_dma_x_modify(CH_SPI, 1); + dma_width = WDSIZE_8; + } + + /* set transfer width,direction. And enable spi */ + cr = (read_CTRL() & (~BIT_CTL_TIMOD)); + + /* dirty hack for autobuffer DMA mode */ + if (drv_data->tx_dma == 0xFFFF) { + pr_debug("doing autobuffer DMA out.\n"); + + /* no irq in autobuffer mode */ + dma_config = + (DMAFLOW_AUTO | RESTART | dma_width | DI_EN); + set_dma_config(CH_SPI, dma_config); + set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx); + enable_dma(CH_SPI); + write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) | + (CFG_SPI_ENABLE << 14)); + + /* just return here, there can only be one transfer in this mode */ + message->status = 0; + giveback(drv_data); + return; + } + + /* In dma mode, rx or tx must be NULL in one transfer */ + if (drv_data->rx != NULL) { + /* set transfer mode, and enable SPI */ + pr_debug("doing DMA in.\n"); + + /* disable SPI before write to TDBR */ + write_CTRL(cr & ~BIT_CTL_ENABLE); + + /* clear tx reg soformer data is not shifted out */ + write_TDBR(0xFF); + + set_dma_x_count(CH_SPI, drv_data->len); + + /* start dma */ + dma_enable_irq(CH_SPI); + dma_config = (WNR | RESTART | dma_width | DI_EN); + set_dma_config(CH_SPI, dma_config); + set_dma_start_addr(CH_SPI, (unsigned long)drv_data->rx); + enable_dma(CH_SPI); + + cr |= + CFG_SPI_DMAREAD | (width << 8) | (CFG_SPI_ENABLE << + 14); + /* set transfer mode, and enable SPI */ + write_CTRL(cr); + } else if (drv_data->tx != NULL) { + pr_debug("doing DMA out.\n"); + + /* start dma */ + dma_enable_irq(CH_SPI); + dma_config = (RESTART | dma_width | DI_EN); + set_dma_config(CH_SPI, dma_config); + set_dma_start_addr(CH_SPI, (unsigned long)drv_data->tx); + enable_dma(CH_SPI); + + write_CTRL(cr | CFG_SPI_DMAWRITE | (width << 8) | + (CFG_SPI_ENABLE << 14)); + + } + } else { + /* IO mode write then read */ + pr_debug("doing IO transfer\n"); + + write_STAT(BIT_STAT_CLR); + + if (drv_data->tx != NULL && drv_data->rx != NULL) { + /* full duplex mode */ + BUG_ON((drv_data->tx_end - drv_data->tx) != + (drv_data->rx_end - drv_data->rx)); + cr = (read_CTRL() & (~BIT_CTL_TIMOD)); /* clear the TIMOD bits */ + cr |= + CFG_SPI_WRITE | (width << 8) | (CFG_SPI_ENABLE << + 14); + pr_debug("IO duplex: cr is 0x%x\n", cr); + + write_CTRL(cr); + SSYNC(); + + drv_data->duplex(drv_data); + + if (drv_data->tx != drv_data->tx_end) + tranf_success = 0; + } else if (drv_data->tx != NULL) { + /* write only half duplex */ + cr = (read_CTRL() & (~BIT_CTL_TIMOD)); /* clear the TIMOD bits */ + cr |= + CFG_SPI_WRITE | (width << 8) | (CFG_SPI_ENABLE << + 14); + pr_debug("IO write: cr is 0x%x\n", cr); + + write_CTRL(cr); + SSYNC(); + + drv_data->write(drv_data); + + if (drv_data->tx != drv_data->tx_end) + tranf_success = 0; + } else if (drv_data->rx != NULL) { + /* read only half duplex */ + cr = (read_CTRL() & (~BIT_CTL_TIMOD)); /* cleare the TIMOD bits */ + cr |= + CFG_SPI_READ | (width << 8) | (CFG_SPI_ENABLE << + 14); + pr_debug("IO read: cr is 0x%x\n", cr); + + write_CTRL(cr); + SSYNC(); + + drv_data->read(drv_data); + if (drv_data->rx != drv_data->rx_end) + tranf_success = 0; + } + + if (!tranf_success) { + pr_debug("IO write error!\n"); + message->state = ERROR_STATE; + } else { + /* Update total byte transfered */ + message->actual_length += drv_data->len; + + /* Move to next transfer of this msg */ + message->state = next_transfer(drv_data); + } + + /* Schedule next transfer tasklet */ + tasklet_schedule(&drv_data->pump_transfers); + + } +} + +/* pop a msg from queue and kick off real transfer */ +static void pump_messages(struct work_struct *work) +{ + struct driver_data *drv_data = container_of(work, struct driver_data, pump_messages); + unsigned long flags; + + /* Lock queue and check for queue work */ + spin_lock_irqsave(&drv_data->lock, flags); + if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) { + /* pumper kicked off but no work to do */ + drv_data->busy = 0; + spin_unlock_irqrestore(&drv_data->lock, flags); + return; + } + + /* Make sure we are not already running a message */ + if (drv_data->cur_msg) { + spin_unlock_irqrestore(&drv_data->lock, flags); + return; + } + + /* Extract head of queue */ + drv_data->cur_msg = list_entry(drv_data->queue.next, + struct spi_message, queue); + list_del_init(&drv_data->cur_msg->queue); + + /* Initial message state */ + drv_data->cur_msg->state = START_STATE; + drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next, + struct spi_transfer, transfer_list); + + /* Setup the SSP using the per chip configuration */ + drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi); + restore_state(drv_data); + pr_debug + ("got a message to pump, state is set to: baud %d, flag 0x%x, ctl 0x%x\n", + drv_data->cur_chip->baud, drv_data->cur_chip->flag, + drv_data->cur_chip->ctl_reg); + pr_debug("the first transfer len is %d\n", drv_data->cur_transfer->len); + + /* Mark as busy and launch transfers */ + tasklet_schedule(&drv_data->pump_transfers); + + drv_data->busy = 1; + spin_unlock_irqrestore(&drv_data->lock, flags); +} + +/* + * got a msg to transfer, queue it in drv_data->queue. + * And kick off message pumper + */ +static int transfer(struct spi_device *spi, struct spi_message *msg) +{ + struct driver_data *drv_data = spi_master_get_devdata(spi->master); + unsigned long flags; + + spin_lock_irqsave(&drv_data->lock, flags); + + if (drv_data->run == QUEUE_STOPPED) { + spin_unlock_irqrestore(&drv_data->lock, flags); + return -ESHUTDOWN; + } + + msg->actual_length = 0; + msg->status = -EINPROGRESS; + msg->state = START_STATE; + + pr_debug("adding an msg in transfer() \n"); + list_add_tail(&msg->queue, &drv_data->queue); + + if (drv_data->run == QUEUE_RUNNING && !drv_data->busy) + queue_work(drv_data->workqueue, &drv_data->pump_messages); + + spin_unlock_irqrestore(&drv_data->lock, flags); + + return 0; +} + +/* first setup for new devices */ +static int setup(struct spi_device *spi) +{ + struct bfin5xx_spi_chip *chip_info = NULL; + struct chip_data *chip; + struct driver_data *drv_data = spi_master_get_devdata(spi->master); + u8 spi_flg; + + /* Abort device setup if requested features are not supported */ + if (spi->mode & ~(SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST)) { + dev_err(&spi->dev, "requested mode not fully supported\n"); + return -EINVAL; + } + + /* Zero (the default) here means 8 bits */ + if (!spi->bits_per_word) + spi->bits_per_word = 8; + + if (spi->bits_per_word != 8 && spi->bits_per_word != 16) + return -EINVAL; + + /* Only alloc (or use chip_info) on first setup */ + chip = spi_get_ctldata(spi); + if (chip == NULL) { + chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); + if (!chip) + return -ENOMEM; + + chip->enable_dma = 0; + chip_info = spi->controller_data; + } + + /* chip_info isn't always needed */ + if (chip_info) { + chip->enable_dma = chip_info->enable_dma != 0 + && drv_data->master_info->enable_dma; + chip->ctl_reg = chip_info->ctl_reg; + chip->bits_per_word = chip_info->bits_per_word; + chip->cs_change_per_word = chip_info->cs_change_per_word; + chip->cs_chg_udelay = chip_info->cs_chg_udelay; + } + + /* translate common spi framework into our register */ + if (spi->mode & SPI_CPOL) + chip->ctl_reg |= CPOL; + if (spi->mode & SPI_CPHA) + chip->ctl_reg |= CPHA; + if (spi->mode & SPI_LSB_FIRST) + chip->ctl_reg |= LSBF; + /* we dont support running in slave mode (yet?) */ + chip->ctl_reg |= MSTR; + + /* + * if any one SPI chip is registered and wants DMA, request the + * DMA channel for it + */ + if (chip->enable_dma && !dma_requested) { + /* register dma irq handler */ + if (request_dma(CH_SPI, "BF53x_SPI_DMA") < 0) { + pr_debug + ("Unable to request BlackFin SPI DMA channel\n"); + return -ENODEV; + } + if (set_dma_callback(CH_SPI, (void *)dma_irq_handler, drv_data) + < 0) { + pr_debug("Unable to set dma callback\n"); + return -EPERM; + } + dma_disable_irq(CH_SPI); + dma_requested = 1; + } + + /* + * Notice: for blackfin, the speed_hz is the value of register + * SPI_BAUD, not the real baudrate + */ + chip->baud = hz_to_spi_baud(spi->max_speed_hz); + spi_flg = ~(1 << (spi->chip_select)); + chip->flag = ((u16) spi_flg << 8) | (1 << (spi->chip_select)); + chip->chip_select_num = spi->chip_select; + + switch (chip->bits_per_word) { + case 8: + chip->n_bytes = 1; + chip->width = CFG_SPI_WORDSIZE8; + chip->read = chip->cs_change_per_word ? + u8_cs_chg_reader : u8_reader; + chip->write = chip->cs_change_per_word ? + u8_cs_chg_writer : u8_writer; + chip->duplex = chip->cs_change_per_word ? + u8_cs_chg_duplex : u8_duplex; + break; + + case 16: + chip->n_bytes = 2; + chip->width = CFG_SPI_WORDSIZE16; + chip->read = chip->cs_change_per_word ? + u16_cs_chg_reader : u16_reader; + chip->write = chip->cs_change_per_word ? + u16_cs_chg_writer : u16_writer; + chip->duplex = chip->cs_change_per_word ? + u16_cs_chg_duplex : u16_duplex; + break; + + default: + dev_err(&spi->dev, "%d bits_per_word is not supported\n", + chip->bits_per_word); + kfree(chip); + return -ENODEV; + } + + pr_debug("setup spi chip %s, width is %d, dma is %d,", + spi->modalias, chip->width, chip->enable_dma); + pr_debug("ctl_reg is 0x%x, flag_reg is 0x%x\n", + chip->ctl_reg, chip->flag); + + spi_set_ctldata(spi, chip); + + return 0; +} + +/* + * callback for spi framework. + * clean driver specific data + */ +static void cleanup(const struct spi_device *spi) +{ + struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi); + + kfree(chip); +} + +static inline int init_queue(struct driver_data *drv_data) +{ + INIT_LIST_HEAD(&drv_data->queue); + spin_lock_init(&drv_data->lock); + + drv_data->run = QUEUE_STOPPED; + drv_data->busy = 0; + + /* init transfer tasklet */ + tasklet_init(&drv_data->pump_transfers, + pump_transfers, (unsigned long)drv_data); + + /* init messages workqueue */ + INIT_WORK(&drv_data->pump_messages, pump_messages); + drv_data->workqueue = + create_singlethread_workqueue(drv_data->master->cdev.dev->bus_id); + if (drv_data->workqueue == NULL) + return -EBUSY; + + return 0; +} + +static inline int start_queue(struct driver_data *drv_data) +{ + unsigned long flags; + + spin_lock_irqsave(&drv_data->lock, flags); + + if (drv_data->run == QUEUE_RUNNING || drv_data->busy) { + spin_unlock_irqrestore(&drv_data->lock, flags); + return -EBUSY; + } + + drv_data->run = QUEUE_RUNNING; + drv_data->cur_msg = NULL; + drv_data->cur_transfer = NULL; + drv_data->cur_chip = NULL; + spin_unlock_irqrestore(&drv_data->lock, flags); + + queue_work(drv_data->workqueue, &drv_data->pump_messages); + + return 0; +} + +static inline int stop_queue(struct driver_data *drv_data) +{ + unsigned long flags; + unsigned limit = 500; + int status = 0; + + spin_lock_irqsave(&drv_data->lock, flags); + + /* + * This is a bit lame, but is optimized for the common execution path. + * A wait_queue on the drv_data->busy could be used, but then the common + * execution path (pump_messages) would be required to call wake_up or + * friends on every SPI message. Do this instead + */ + drv_data->run = QUEUE_STOPPED; + while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) { + spin_unlock_irqrestore(&drv_data->lock, flags); + msleep(10); + spin_lock_irqsave(&drv_data->lock, flags); + } + + if (!list_empty(&drv_data->queue) || drv_data->busy) + status = -EBUSY; + + spin_unlock_irqrestore(&drv_data->lock, flags); + + return status; +} + +static inline int destroy_queue(struct driver_data *drv_data) +{ + int status; + + status = stop_queue(drv_data); + if (status != 0) + return status; + + destroy_workqueue(drv_data->workqueue); + + return 0; +} + +static int __init bfin5xx_spi_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct bfin5xx_spi_master *platform_info; + struct spi_master *master; + struct driver_data *drv_data = 0; + int status = 0; + + platform_info = dev->platform_data; + + /* Allocate master with space for drv_data */ + master = spi_alloc_master(dev, sizeof(struct driver_data) + 16); + if (!master) { + dev_err(&pdev->dev, "can not alloc spi_master\n"); + return -ENOMEM; + } + drv_data = spi_master_get_devdata(master); + drv_data->master = master; + drv_data->master_info = platform_info; + drv_data->pdev = pdev; + + master->bus_num = pdev->id; + master->num_chipselect = platform_info->num_chipselect; + master->cleanup = cleanup; + master->setup = setup; + master->transfer = transfer; + + /* Initial and start queue */ + status = init_queue(drv_data); + if (status != 0) { + dev_err(&pdev->dev, "problem initializing queue\n"); + goto out_error_queue_alloc; + } + status = start_queue(drv_data); + if (status != 0) { + dev_err(&pdev->dev, "problem starting queue\n"); + goto out_error_queue_alloc; + } + + /* Register with the SPI framework */ + platform_set_drvdata(pdev, drv_data); + status = spi_register_master(master); + if (status != 0) { + dev_err(&pdev->dev, "problem registering spi master\n"); + goto out_error_queue_alloc; + } + pr_debug("controller probe successfully\n"); + return status; + + out_error_queue_alloc: + destroy_queue(drv_data); + spi_master_put(master); + return status; +} + +/* stop hardware and remove the driver */ +static int __devexit bfin5xx_spi_remove(struct platform_device *pdev) +{ + struct driver_data *drv_data = platform_get_drvdata(pdev); + int status = 0; + + if (!drv_data) + return 0; + + /* Remove the queue */ + status = destroy_queue(drv_data); + if (status != 0) + return status; + + /* Disable the SSP at the peripheral and SOC level */ + bfin_spi_disable(drv_data); + + /* Release DMA */ + if (drv_data->master_info->enable_dma) { + if (dma_channel_active(CH_SPI)) + free_dma(CH_SPI); + } + + /* Disconnect from the SPI framework */ + spi_unregister_master(drv_data->master); + + /* Prevent double remove */ + platform_set_drvdata(pdev, NULL); + + return 0; +} + +#ifdef CONFIG_PM +static int bfin5xx_spi_suspend(struct platform_device *pdev, pm_message_t state) +{ + struct driver_data *drv_data = platform_get_drvdata(pdev); + int status = 0; + + status = stop_queue(drv_data); + if (status != 0) + return status; + + /* stop hardware */ + bfin_spi_disable(drv_data); + + return 0; +} + +static int bfin5xx_spi_resume(struct platform_device *pdev) +{ + struct driver_data *drv_data = platform_get_drvdata(pdev); + int status = 0; + + /* Enable the SPI interface */ + bfin_spi_enable(drv_data); + + /* Start the queue running */ + status = start_queue(drv_data); + if (status != 0) { + dev_err(&pdev->dev, "problem starting queue (%d)\n", status); + return status; + } + + return 0; +} +#else +#define bfin5xx_spi_suspend NULL +#define bfin5xx_spi_resume NULL +#endif /* CONFIG_PM */ + +static struct platform_driver bfin5xx_spi_driver = { + .driver = { + .name = "bfin-spi-master", + .bus = &platform_bus_type, + .owner = THIS_MODULE, + }, + .probe = bfin5xx_spi_probe, + .remove = __devexit_p(bfin5xx_spi_remove), + .suspend = bfin5xx_spi_suspend, + .resume = bfin5xx_spi_resume, +}; + +static int __init bfin5xx_spi_init(void) +{ + return platform_driver_register(&bfin5xx_spi_driver); +} + +module_init(bfin5xx_spi_init); + +static void __exit bfin5xx_spi_exit(void) +{ + platform_driver_unregister(&bfin5xx_spi_driver); +} + +module_exit(bfin5xx_spi_exit); |