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SubjectRe: [PATCH take #5] [libata] libata driver for bf548 on chip ATAPI controller.
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@analog.com>
> ---
> 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@analog.com>
> + *
> + * 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@analog.com>");
> +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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