Re: [PATCH take #5] [libata] libata driver for bf548 on chip ATAPIcontroller.

From: Jeff Garzik
Date: Thu Aug 16 2007 - 03:04:47 EST


Sonic Zhang wrote:
Update:
1. Condition branch code instead of while loop from Alan Cox.
2. Condtinue in PIO mode after failing to request DMA.

Signed-off-by: Sonic Zhang <sonic.zhang@xxxxxxxxxx>
---
drivers/ata/Kconfig | 28 +
drivers/ata/Makefile | 1
drivers/ata/pata_bf54x.c | 1581 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1610 insertions(+)

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index b4a8d60..e679f04 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -583,4 +583,32 @@ config PATA_SCC
If unsure, say N.
+config PATA_BF54X
+ tristate "Blackfin 54x ATAPI support"
+ depends on BF542 || BF548 || BF549
+ help
+ This option enables support for the built-in ATAPI controller on
+ Blackfin 54x family chips.
+
+ If unsure, say N.
+
+choice
+ prompt "Blackfin 54x ATAPI mode"
+ depends on PATA_BF54X
+ default PATA_BF54X_DMA
+ help
+ This option selects bf54x ATAPI controller working mode.
+
+config PATA_BF54X_PIO
+ bool "PIO mode"
+ help
+ Blackfin ATAPI controller works under PIO mode.
+
+config PATA_BF54X_DMA
+ bool "DMA mode"
+ help
+ Blackfin ATAPI controller works under DMA mode.


Given update #2 at the top of your message, I would think a more natural Kconfig setup would now be a simple "DMA support?" yes/no setting. PIO would theoretically always be present as a fallback, I would think.


diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 8149c68..c2ecba5 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_PATA_SIS) += pata_sis.o
obj-$(CONFIG_PATA_TRIFLEX) += pata_triflex.o
obj-$(CONFIG_PATA_IXP4XX_CF) += pata_ixp4xx_cf.o
obj-$(CONFIG_PATA_SCC) += pata_scc.o
+obj-$(CONFIG_PATA_BF54X) += pata_bf54x.o
obj-$(CONFIG_PATA_PLATFORM) += pata_platform.o
obj-$(CONFIG_PATA_ICSIDE) += pata_icside.o
# Should be last but one libata driver
diff --git a/drivers/ata/pata_bf54x.c b/drivers/ata/pata_bf54x.c
new file mode 100644
index 0000000..d0f52b0
--- /dev/null
+++ b/drivers/ata/pata_bf54x.c
@@ -0,0 +1,1581 @@
+/*
+ * File: drivers/ata/pata_bf54x.c
+ * Author: Sonic Zhang <sonic.zhang@xxxxxxxxxx>
+ *
+ * Created:
+ * Description: ATAPI Driver for blackfin 54x

Terminology: When used alone, "ATAPI" normally refers to CD/DVD-ROM style devices. A better description would be "PATA driver for ..."


+#define DRV_NAME "bf54x-atapi"
+#define DRV_VERSION "0.6"

DRV_NAME should be "pata_bf54x"


+#define ATA_REG_CTRL 0x0E
+#define ATA_REG_ALTSTATUS ATA_REG_CTRL

a simple comment at the beginning of this list, noting that these are the controller's registers, would be nice


+#define ATAPI_OFFSET_CONTROL 0x00
+#define ATAPI_OFFSET_STATUS 0x04
+#define ATAPI_OFFSET_DEV_ADDR 0x08
+#define ATAPI_OFFSET_DEV_TXBUF 0x0c
+#define ATAPI_OFFSET_DEV_RXBUF 0x10
+#define ATAPI_OFFSET_INT_MASK 0x14
+#define ATAPI_OFFSET_INT_STATUS 0x18
+#define ATAPI_OFFSET_XFER_LEN 0x1c
+#define ATAPI_OFFSET_LINE_STATUS 0x20
+#define ATAPI_OFFSET_SM_STATE 0x24
+#define ATAPI_OFFSET_TERMINATE 0x28
+#define ATAPI_OFFSET_PIO_TFRCNT 0x2c
+#define ATAPI_OFFSET_DMA_TFRCNT 0x30
+#define ATAPI_OFFSET_UMAIN_TFRCNT 0x34
+#define ATAPI_OFFSET_UDMAOUT_TFRCNT 0x38
+#define ATAPI_OFFSET_REG_TIM_0 0x40
+#define ATAPI_OFFSET_PIO_TIM_0 0x44
+#define ATAPI_OFFSET_PIO_TIM_1 0x48
+#define ATAPI_OFFSET_MULTI_TIM_0 0x50
+#define ATAPI_OFFSET_MULTI_TIM_1 0x54
+#define ATAPI_OFFSET_MULTI_TIM_2 0x58
+#define ATAPI_OFFSET_ULTRA_TIM_0 0x60
+#define ATAPI_OFFSET_ULTRA_TIM_1 0x64
+#define ATAPI_OFFSET_ULTRA_TIM_2 0x68
+#define ATAPI_OFFSET_ULTRA_TIM_3 0x6c
+
+
+/**
+ * PIO Mode - Frequency compatibility
+ */
+/* mode: 0 1 2 3 4 */
+static u32 pio_fsclk[] =
+{ 33333333, 33333333, 33333333, 33333333, 33333333 };
+
+/**
+ * MDMA Mode - Frequency compatibility
+ */
+/* mode: 0 1 2 */
+static u32 mdma_fsclk[] = { 33333333, 33333333, 33333333 };
+
+/**
+ * UDMA Mode - Frequency compatibility
+ *
+ * UDMA5 - 100 MB/s - SCLK = 133 MHz
+ * UDMA4 - 66 MB/s - SCLK >= 80 MHz
+ * UDMA3 - 44.4 MB/s - SCLK >= 50 MHz
+ * UDMA2 - 33 MB/s - SCLK >= 40 MHz
+ */
+/* mode: 0 1 2 3 4 5 */
+static u32 udma_fsclk[] =
+{ 33333333, 33333333, 40000000, 50000000, 80000000, 133333333 };
+
+/**
+ * Register transfer timing table
+ */
+/* mode: 0 1 2 3 4 */
+/* Cycle Time */
+static u32 reg_t0min[] = { 600, 383, 330, 180, 120 };
+/* DIOR/DIOW to end cycle */
+static u32 reg_t2min[] = { 290, 290, 290, 70, 25 };
+/* DIOR/DIOW asserted pulse width */
+static u32 reg_teocmin[] = { 290, 290, 290, 80, 70 };
+
+/**
+ * PIO timing table
+ */
+/* mode: 0 1 2 3 4 */
+/* Cycle Time */
+static u32 pio_t0min[] = { 600, 383, 240, 180, 120 };
+/* Address valid to DIOR/DIORW */
+static u32 pio_t1min[] = { 70, 50, 30, 30, 25 };
+/* DIOR/DIOW to end cycle */
+static u32 pio_t2min[] = { 165, 125, 100, 80, 70 };
+/* DIOR/DIOW asserted pulse width */
+static u32 pio_teocmin[] = { 165, 125, 100, 70, 25 };
+/* DIOW data hold */
+static u32 pio_t4min[] = { 30, 20, 15, 10, 10 };
+
+/* ******************************************************************
+ * Multiword DMA timing table
+ * ******************************************************************
+ */
+/* mode: 0 1 2 */
+/* Cycle Time */
+static u32 mdma_t0min[] = { 480, 150, 120 };
+/* DIOR/DIOW asserted pulse width */
+static u32 mdma_tdmin[] = { 215, 80, 70 };
+/* DMACK to read data released */
+static u32 mdma_thmin[] = { 20, 15, 10 };
+/* DIOR/DIOW to DMACK hold */
+static u32 mdma_tjmin[] = { 20, 5, 5 };
+/* DIOR negated pulse width */
+static u32 mdma_tkrmin[] = { 50, 50, 25 };
+/* DIOR negated pulse width */
+static u32 mdma_tkwmin[] = { 215, 50, 25 };
+/* CS[1:0] valid to DIOR/DIOW */
+static u32 mdma_tmmin[] = { 50, 30, 25 };
+/* DMACK to read data released */
+static u32 mdma_tzmax[] = { 20, 25, 25 };
+
+/**
+ * Ultra DMA timing table
+ */
+/* mode: 0 1 2 3 4 5 */
+static u32 udma_tcycmin[] = { 112, 73, 54, 39, 25, 17 };
+static u32 udma_tdvsmin[] = { 70, 48, 31, 20, 7, 5 };
+static u32 udma_tenvmax[] = { 70, 70, 70, 55, 55, 50 };
+static u32 udma_trpmin[] = { 160, 125, 100, 100, 100, 85 };
+static u32 udma_tmin[] = { 5, 5, 5, 5, 3, 3 };
+
+
+static u32 udma_tmlimin = 20;
+static u32 udma_tzahmin = 20;
+static u32 udma_tenvmin = 20;
+static u32 udma_tackmin = 20;
+static u32 udma_tssmin = 50;

how many of these can be marked 'static const'?


+static unsigned short num_clocks_min(unsigned long tmin,
+ unsigned long fsclk)
+{
+ unsigned long tmp ;
+ unsigned short result;
+
+ tmp = tmin * (fsclk/1000/1000) / 1000;
+ result = (unsigned short)tmp;
+ if ((tmp*1000*1000) < (tmin*(fsclk/1000))) {
+ result++;
+ }
+
+ return result;
+}
+
+/**
+ * bfin_set_piomode - Initialize host controller PATA PIO timings
+ * @ap: Port whose timings we are configuring
+ * @adev: um
+ *
+ * Set PIO mode for device.
+ *
+ * LOCKING:
+ * None (inherited from caller).
+ */
+
+static void bfin_set_piomode(struct ata_port *ap, struct ata_device *adev)
+{
+ int mode = adev->pio_mode - XFER_PIO_0;
+ unsigned long base = (unsigned long)ap->ioaddr.ctl_addr;


(added Bryan Wu to CC)

Someone needs to need fix the bfin architecture: the addresses on the bfin_read/bfin_write functions should be 'void __iomem *' not unsigned long.

Also, it would make this driver quite a bit smaller if you can use the ioread/iowrite (iomap) functions provided by the architecture. Then you can use a lot of the standard libata helper functions.



+ unsigned int fsclk = get_sclk();
+ unsigned short teoc_reg, t2_reg, teoc_pio;
+ unsigned short t4_reg, t2_pio, t1_reg;
+ unsigned short n0, n6, t6min = 5;
+
+ /* the most restrictive timing value is t6 and tc, the DIOW - data hold
+ * If one SCLK pulse is longer than this minimum value then register
+ * transfers cannot be supported at this frequency.
+ */
+ n6 = num_clocks_min(t6min, fsclk);
+ if (mode >= 0 && mode <= 4 && n6 >= 1) {
+ pr_debug("set piomode: mode=%d, fsclk=%ud\n", mode, fsclk);
+ /* calculate the timing values for register transfers. */
+ while (mode > 0 && pio_fsclk[mode] > fsclk) {
+ mode--;
+ }

In Linux kernel code, we prefer that single C statements not be surrounded by [optional] braces.


+ /* DIOR/DIOW to end cycle time */
+ t2_reg = num_clocks_min(reg_t2min[mode], fsclk);
+ /* DIOR/DIOW asserted pulse width */
+ teoc_reg = num_clocks_min(reg_teocmin[mode], fsclk);
+ /* Cycle Time */
+ n0 = num_clocks_min(reg_t0min[mode], fsclk);
+
+ /* increase t2 until we meed the minimum cycle length */
+ if (t2_reg + teoc_reg < n0)
+ t2_reg = n0 - teoc_reg;
+
+ /* calculate the timing values for pio transfers. */
+
+ /* DIOR/DIOW to end cycle time */
+ t2_pio = num_clocks_min(pio_t2min[mode], fsclk);
+ /* DIOR/DIOW asserted pulse width */
+ teoc_pio = num_clocks_min(pio_teocmin[mode], fsclk);
+ /* Cycle Time */
+ n0 = num_clocks_min(pio_t0min[mode], fsclk);
+
+ /* increase t2 until we meed the minimum cycle length */
+ if (t2_pio + teoc_pio < n0)
+ t2_pio = n0 - teoc_pio;
+
+ /* Address valid to DIOR/DIORW */
+ t1_reg = num_clocks_min(pio_t1min[mode], fsclk);
+
+ /* DIOW data hold */
+ t4_reg = num_clocks_min(pio_t4min[mode], fsclk);
+
+ ATAPI_SET_REG_TIM_0(base, (teoc_reg<<8 | t2_reg));
+ ATAPI_SET_PIO_TIM_0(base, (t4_reg<<12 | t2_pio<<4 | t1_reg));
+ ATAPI_SET_PIO_TIM_1(base, teoc_pio);
+ if (mode > 2) {
+ ATAPI_SET_CONTROL(base,
+ ATAPI_GET_CONTROL(base) | IORDY_EN);
+ } else {
+ ATAPI_SET_CONTROL(base,
+ ATAPI_GET_CONTROL(base) & ~IORDY_EN);
+ }
+
+ /* Disable host ATAPI PIO interrupts */
+ ATAPI_SET_INT_MASK(base, ATAPI_GET_INT_MASK(base)
+ & ~(PIO_DONE_MASK | HOST_TERM_XFER_MASK));
+ SSYNC();
+ }
+}
+
+/**
+ * bfin_set_dmamode - Initialize host controller PATA DMA timings
+ * @ap: Port whose timings we are configuring
+ * @adev: um
+ * @udma: udma mode, 0 - 6
+ *
+ * Set UDMA mode for device.
+ *
+ * LOCKING:
+ * None (inherited from caller).
+ */
+
+static void bfin_set_dmamode (struct ata_port *ap, struct ata_device *adev)
+{
+ int mode;
+ unsigned long base = (unsigned long)ap->ioaddr.ctl_addr;
+ unsigned long fsclk = get_sclk();
+ unsigned short tenv, tack, tcyc_tdvs, tdvs, tmli, tss, trp, tzah;
+ unsigned short tm, td, tkr, tkw, teoc, th;
+ unsigned short n0, nf, tfmin = 5;
+ unsigned short nmin, tcyc;

+/**
+ *
+ * Function: wait_complete
+ *
+ * Description: Waits the interrupt from device
+ *
+ */
+static void inline wait_complete(unsigned long base, unsigned short mask)
+{
+ unsigned short status;
+
+ do {
+ status = ATAPI_GET_INT_STATUS(base) & mask;
+ } while (!status);
+
+ ATAPI_SET_INT_STATUS(base, mask);
+}

no infinite loops, please. always make sure the function errors out after (100? 1000? 100000?) iterations.





+ */
+
+static void bfin_bmdma_setup (struct ata_queued_cmd *qc)
+{
+ unsigned short config = WDSIZE_16;
+ struct scatterlist *sg;
+
+ pr_debug("in atapi dma setup\n");
+ /* Program the ATA_CTRL register with dir */
+ if (qc->tf.flags & ATA_TFLAG_WRITE) {
+ /* fill the ATAPI DMA controller */
+ set_dma_config(CH_ATAPI_TX, config);
+ set_dma_x_modify(CH_ATAPI_TX, 2);
+ ata_for_each_sg(sg, qc) {
+ set_dma_start_addr(CH_ATAPI_TX, sg_dma_address(sg));
+ set_dma_x_count(CH_ATAPI_TX, sg_dma_len(sg) >> 1);
+ }
+ } else {
+ config |= WNR;
+ /* fill the ATAPI DMA controller */
+ set_dma_config(CH_ATAPI_RX, config);
+ set_dma_x_modify(CH_ATAPI_RX, 2);
+ ata_for_each_sg(sg, qc) {
+ set_dma_start_addr(CH_ATAPI_RX, sg_dma_address(sg));
+ set_dma_x_count(CH_ATAPI_RX, sg_dma_len(sg) >> 1);
+ }
+ }
+}
+
+/**
+ * bfin_bmdma_start - Start an IDE DMA transaction
+ * @qc: Info associated with this ATA transaction.
+ *
+ * Note: Original code is ata_bmdma_start().
+ */
+
+static void bfin_bmdma_start (struct ata_queued_cmd *qc)
+{
+ struct ata_port *ap = qc->ap;
+ unsigned long base = (unsigned long)ap->ioaddr.ctl_addr;
+ struct scatterlist *sg;
+
+ pr_debug("in atapi dma start\n");
+ if (ap->udma_mask || ap->mwdma_mask) {

invert this test, and have it return from the function early if so.

this allows you to un-indent the following section of code, making it easier to read.


+ /* start ATAPI DMA controller*/
+ if (qc->tf.flags & ATA_TFLAG_WRITE) {

a comment explaining what the flush_dcache_range() loop is accomplishing would be nice


+ ata_for_each_sg(sg, qc) {
+ flush_dcache_range(sg_dma_address(sg),
+ sg_dma_address(sg) + sg_dma_len(sg));
+ }
+ enable_dma(CH_ATAPI_TX);
+ pr_debug("enable udma write\n");
+
+ /* Send ATA DMA write command */
+ bfin_exec_command(ap, &qc->tf);
+
+ /* set ATA DMA write direction */
+ ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base)
+ | XFER_DIR));
+ } else {
+ enable_dma(CH_ATAPI_RX);
+ pr_debug("enable udma read\n");
+
+ /* Send ATA DMA read command */
+ bfin_exec_command(ap, &qc->tf);
+
+ /* set ATA DMA read direction */
+ ATAPI_SET_CONTROL(base, (ATAPI_GET_CONTROL(base)
+ & ~XFER_DIR));
+ }
+
+ /* Reset all transfer count */
+ ATAPI_SET_CONTROL(base,
+ ATAPI_GET_CONTROL(base) | TFRCNT_RST);
+
+ /* Set transfer length to buffer len */
+ ata_for_each_sg(sg, qc) {
+ ATAPI_SET_XFER_LEN(base, (sg_dma_len(sg) >> 1));
+ }
+
+ /* Enable ATA DMA operation*/
+ if (ap->udma_mask) {
+ ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base)
+ | ULTRA_START);
+ } else {
+ ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base)
+ | MULTI_START);
+ }
+ }
+}
+
+/**
+ * bfin_bmdma_stop - Stop IDE DMA transfer
+ * @qc: Command we are ending DMA for
+ */
+
+static void bfin_bmdma_stop (struct ata_queued_cmd *qc)
+{
+ struct ata_port *ap = qc->ap;
+ struct scatterlist *sg;
+
+ pr_debug("in atapi dma stop\n");
+ if (ap->udma_mask || ap->mwdma_mask) {

ditto -- invert test and return early.

then, un-indent all code following.


+ /* stop ATAPI DMA controller*/
+ if (qc->tf.flags & ATA_TFLAG_WRITE) {
+ disable_dma(CH_ATAPI_TX);
+ } else {
+ disable_dma(CH_ATAPI_RX);
+ if (ap->hsm_task_state & HSM_ST_LAST) {

ditto -- a comment explaining the invalidate_dcache_range() loop would be nice.

it really looks like this should be hidden inside the architecture's dma functions, I would think?


+ ata_for_each_sg(sg, qc) {
+ invalidate_dcache_range(
+ sg_dma_address(sg),
+ sg_dma_address(sg)
+ + sg_dma_len(sg));
+ }
+ }
+ }
+ }

you appear to be missing an important error handling operation: thaw


+static void bfin_bmdma_freeze (struct ata_port *ap)
+{
+ unsigned long base = (unsigned long)ap->ioaddr.ctl_addr;
+
+ pr_debug("in atapi dma freeze\n");
+ ap->ctl |= ATA_NIEN;
+ ap->last_ctl = ap->ctl;
+
+ write_atapi_register(base, ATA_REG_CTRL, ap->ctl);
+
+ /* Under certain circumstances, some controllers raise IRQ on
+ * ATA_NIEN manipulation. Also, many controllers fail to mask
+ * previously pending IRQ on ATA_NIEN assertion. Clear it.
+ */
+ ata_chk_status(ap);
+
+ ap->ops->irq_clear(ap);

All occurences of "ap->ops->..." in this driver may be replaced with direct calls to functions.



+ * bfin_std_postreset - standard postreset callback
+ * @ap: the target ata_port
+ * @classes: classes of attached devices
+ *
+ * Note: Original code is ata_std_postreset().
+ */
+
+static void bfin_std_postreset (struct ata_port *ap, unsigned int *classes)
+{
+ unsigned long base = (unsigned long)ap->ioaddr.ctl_addr;
+
+ /* re-enable interrupts */
+ if (!ap->ops->error_handler)
+ ap->ops->irq_on(ap);

->error_handler is always non-NULL for this driver


+ /* is double-select really necessary? */
+ if (classes[0] != ATA_DEV_NONE)
+ ap->ops->dev_select(ap, 1);
+ if (classes[1] != ATA_DEV_NONE)
+ ap->ops->dev_select(ap, 0);
+
+ /* bail out if no device is present */
+ if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
+ return;
+ }
+
+ /* set up device control */
+ write_atapi_register(base, ATA_REG_CTRL, ap->ctl);
+}
+
+/**
+ * bfin_error_handler - Stock error handler for DMA controller
+ * @ap: port to handle error for
+ */
+
+static void bfin_error_handler (struct ata_port *ap)
+{
+ ata_bmdma_drive_eh(ap, ata_std_prereset, bfin_std_softreset, NULL,
+ bfin_std_postreset);
+}
+
+/**
+ * bfin_bmdma_irq_clear - Clear ATAPI interrupt.
+ * @ap: Port associated with this ATA transaction.
+ *
+ * Note: Original code is ata_bmdma_irq_clear().
+ */
+
+static void bfin_bmdma_irq_clear (struct ata_port *ap)
+{
+ unsigned long base = (unsigned long)ap->ioaddr.ctl_addr;
+
+ pr_debug("in atapi irq clear\n");
+ ATAPI_SET_INT_STATUS(base, 0x1FF);
+}
+
+static void bfin_port_stop(struct ata_port *ap)
+{
+ pr_debug("in atapi port stop\n");
+ if (ap->udma_mask != 0 || ap->mwdma_mask != 0) {
+ free_dma(CH_ATAPI_RX);
+ free_dma(CH_ATAPI_TX);
+ }
+}
+
+static int bfin_port_start(struct ata_port *ap)
+{
+ pr_debug("in atapi port start\n");
+ if (ap->udma_mask != 0 || ap->mwdma_mask != 0) {

ditto above comments -- invert test, return early, un-indent code that follows


+ if (request_dma(CH_ATAPI_RX, "BFIN ATAPI RX DMA") >= 0) {
+ if (request_dma(CH_ATAPI_TX,
+ "BFIN ATAPI TX DMA") >= 0) {
+ return 0;
+ }
+ free_dma(CH_ATAPI_RX);
+ }
+ ap->udma_mask = 0;
+ ap->mwdma_mask = 0;
+ dev_err(ap->dev, "Unable to request ATAPI DMA!"
+ " Continue in PIO mode.\n");
+ }
+ return 0;
+}
+
+void bfin_qc_prep(struct ata_queued_cmd *qc)
+{
+}

use ata_noop_qc_prep() and delete the above


+static struct scsi_host_template bfin_sht = {
+ .module = THIS_MODULE,
+ .name = DRV_NAME,
+ .ioctl = ata_scsi_ioctl,
+ .queuecommand = ata_scsi_queuecmd,
+ .can_queue = ATA_DEF_QUEUE,
+ .this_id = ATA_SHT_THIS_ID,
+/* .sg_tablesize = LIBATA_MAX_PRD,*/
+ .sg_tablesize = SG_NONE,
+ .cmd_per_lun = ATA_SHT_CMD_PER_LUN,
+ .emulated = ATA_SHT_EMULATED,
+ .use_clustering = ATA_SHT_USE_CLUSTERING,
+ .proc_name = DRV_NAME,
+ .dma_boundary = ATA_DMA_BOUNDARY,
+ .slave_configure = ata_scsi_slave_config,
+ .slave_destroy = ata_scsi_slave_destroy,
+ .bios_param = ata_std_bios_param,
+#ifdef CONFIG_PM
+ .resume = ata_scsi_device_resume,
+ .suspend = ata_scsi_device_suspend,
+#endif
+};
+
+static const struct ata_port_operations bfin_pata_ops = {
+ .port_disable = ata_port_disable,
+ .set_piomode = bfin_set_piomode,
+ .set_dmamode = bfin_set_dmamode,
+
+ .tf_load = bfin_tf_load,
+ .tf_read = bfin_tf_read,
+ .exec_command = bfin_exec_command,
+ .check_status = bfin_check_status,
+ .check_altstatus = bfin_check_altstatus,
+ .dev_select = bfin_std_dev_select,
+
+ .bmdma_setup = bfin_bmdma_setup,
+ .bmdma_start = bfin_bmdma_start,
+ .bmdma_stop = bfin_bmdma_stop,
+ .bmdma_status = bfin_bmdma_status,
+ .data_xfer = bfin_data_xfer,
+
+ .qc_prep = bfin_qc_prep,
+ .qc_issue = ata_qc_issue_prot,
+
+ .freeze = bfin_bmdma_freeze,
+ .error_handler = bfin_error_handler,
+ .post_internal_cmd = bfin_bmdma_stop,
+
+ .irq_handler = ata_interrupt,
+ .irq_clear = bfin_bmdma_irq_clear,
+ .irq_on = bfin_irq_on,
+ .irq_ack = bfin_irq_ack,
+
+ .port_start = bfin_port_start,
+ .port_stop = bfin_port_stop,
+};
+
+static struct ata_port_info bfin_port_info[] = {
+ {
+ .sht = &bfin_sht,
+ .flags = ATA_FLAG_SLAVE_POSS
+ | ATA_FLAG_MMIO
+ | ATA_FLAG_NO_LEGACY,
+ .pio_mask = 0x1f, /* pio0-4 */
+ .mwdma_mask = 0,
+#ifdef CONFIG_PATA_BF54X_DMA
+ .udma_mask = ATA_UDMA5,
+#else
+ .udma_mask = 0,
+#endif
+ .port_ops = &bfin_pata_ops,
+ },
+};
+
+/**
+ * bfin_reset_controller - initialize BF54x ATAPI controller.
+ */
+
+static int bfin_reset_controller(struct ata_host *host)
+{
+ unsigned long base = (unsigned long)host->ports[0]->ioaddr.ctl_addr;
+ int count;
+ unsigned short status;
+
+ /* Disable all ATAPI interrupts */
+ ATAPI_SET_INT_MASK(base, 0);
+ SSYNC();
+
+ /* Assert the RESET signal 25us*/
+ ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) | DEV_RST);
+ udelay(30);
+
+ /* Negate the RESET signal for 2ms*/
+ ATAPI_SET_CONTROL(base, ATAPI_GET_CONTROL(base) & ~DEV_RST);
+ udelay(2100);

1) udelay() greater than 1000 should be mdelay()

2) you can sleep here, so msleep() is preferred


+ /* Wait on Busy flag to clear */
+ count = 10000000;
+ do {
+ status = read_atapi_register(base, ATA_REG_STATUS);
+ } while (count-- && (status & ATA_BUSY));
+
+ /* Enable only ATAPI Device interrupt */
+ ATAPI_SET_INT_MASK(base, 1);
+ SSYNC();
+
+ return (!count);
+}
+
+/**
+ * atapi_io_port - define atapi peripheral port pins.
+ */
+static unsigned short atapi_io_port[] = {
+ P_ATAPI_RESET,
+ P_ATAPI_DIOR,
+ P_ATAPI_DIOW,
+ P_ATAPI_CS0,
+ P_ATAPI_CS1,
+ P_ATAPI_DMACK,
+ P_ATAPI_DMARQ,
+ P_ATAPI_INTRQ,
+ P_ATAPI_IORDY,
+ 0
+};
+
+/**
+ * bfin_atapi_probe - attach a bfin atapi interface
+ * @pdev: platform device
+ *
+ * Register a bfin atapi interface.
+ *
+ *
+ * Platform devices are expected to contain 2 resources per port:
+ *
+ * - I/O Base (IORESOURCE_IO)
+ * - IRQ (IORESOURCE_IRQ)
+ *
+ */
+static int __devinit bfin_atapi_probe(struct platform_device *pdev)
+{
+ int board_idx = 0;
+ struct resource *res;
+ struct ata_host *host;
+ const struct ata_port_info *ppi[] =
+ { &bfin_port_info[board_idx], NULL };
+
+ /*
+ * Simple resource validation ..
+ */
+ if (unlikely(pdev->num_resources != 2)) {
+ dev_err(&pdev->dev, "invalid number of resources\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Get the register base first
+ */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (res == NULL)
+ return -EINVAL;
+
+ /*
+ * Now that that's out of the way, wire up the port..
+ */
+ host = ata_host_alloc_pinfo(&pdev->dev, ppi, 1);
+ if (!host)
+ return -ENOMEM;
+
+ host->ports[0]->ioaddr.ctl_addr = (void *)res->start;
+
+ if (peripheral_request_list(atapi_io_port, "atapi-io-port")) {
+ dev_err(&pdev->dev, "Requesting Peripherals faild\n");
+ return -EFAULT;
+ }
+
+ if (bfin_reset_controller(host)) {
+ peripheral_free_list(atapi_io_port);
+ dev_err(&pdev->dev, "Fail to reset ATAPI device\n");
+ return -EFAULT;
+ }
+
+ if (ata_host_activate(host, platform_get_irq(pdev, 0),
+ ata_interrupt, IRQF_SHARED, &bfin_sht) != 0) {
+ peripheral_free_list(atapi_io_port);
+ dev_err(&pdev->dev, "Fail to attach ATAPI device\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+/**
+ * bfin_atapi_remove - unplug a bfin atapi interface
+ * @pdev: platform device
+ *
+ * A bfin atapi device has been unplugged. Perform the needed
+ * cleanup. Also called on module unload for any active devices.
+ */
+static int __devexit bfin_atapi_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ata_host *host = dev_get_drvdata(dev);
+
+ ata_host_detach(host);
+
+ peripheral_free_list(atapi_io_port);
+
+ return 0;
+}
+
+static struct platform_driver bfin_atapi_driver = {
+ .probe = bfin_atapi_probe,
+ .remove = __devexit_p(bfin_atapi_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },

if you are going to implement suspend/resume in scsi-host-template, you probably should do so here too


+static int __init bfin_atapi_init (void)
+{
+ pr_info("register bfin atapi driver\n");
+ return platform_driver_register(&bfin_atapi_driver);
+}
+
+static void __exit bfin_atapi_exit (void)
+{
+ platform_driver_unregister(&bfin_atapi_driver);
+}
+
+module_init(bfin_atapi_init);
+module_exit(bfin_atapi_exit);
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@xxxxxxxxxx>");
+MODULE_DESCRIPTION("ATAPI libata driver for blackfin 54x ATAPI controller");

recommend s/ATAPI/PATA/


+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRV_VERSION);



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