* charu@xxxxxx <charu@xxxxxx> [091019 23:41]:
> omap_mcbsp_pollwrite and omap_mcbsp_pollread functions access
> McBSP registers as 16-bit registers.
>
> In OMAP3, McBSP registers (DRR_REG and DXR_REG) are limited to
> 32-bit data accesses (L4 Interconnect). 16-bit and 8-bit is
> not allowed and can corrupt register content.
>
> This patch adds omap3_mcbsp_pollwrite and
> omap3_mcbsp_pollread functions for OMAP3 cpu, inorder to
> perform 32 bit access of above mentioned McBSP registers.
How about making the functions generic, I don't think we want
to have separate omap1_mcbsp_pollread, omap2_mcbsp_pollread,
omap3_mcbsp_pollread..
If it's not obvious how to implement it for some omap, just
return an error based on the CPU type.
Regards,
Tony
> Signed-off-by: Charulatha V <charu@xxxxxx>
> Signed-off-by: Syed Rafiuddin <rafiuddin.syed@xxxxxx>
> ---
> arch/arm/plat-omap/include/mach/mcbsp.h | 4 +
> arch/arm/plat-omap/mcbsp.c | 92 ++++++++++++++++++++++++++++++-
> 2 files changed, 95 insertions(+), 1 deletions(-)
>
> diff --git a/arch/arm/plat-omap/include/mach/mcbsp.h b/arch/arm/plat-omap/include/mach/mcbsp.h
> index 0c5f937..b0f9260 100644
> --- a/arch/arm/plat-omap/include/mach/mcbsp.h
> +++ b/arch/arm/plat-omap/include/mach/mcbsp.h
> @@ -406,6 +406,10 @@ void omap_mcbsp_set_spi_mode(unsigned int id, const struct omap_mcbsp_spi_cfg *
> /* Polled read/write functions */
> int omap_mcbsp_pollread(unsigned int id, u16 * buf);
> int omap_mcbsp_pollwrite(unsigned int id, u16 buf);
> +
> +int omap3_mcbsp_pollread(unsigned int id, u32 *buf);
> +int omap3_mcbsp_pollwrite(unsigned int id, u32 buf);
> +
> int omap_mcbsp_set_io_type(unsigned int id, omap_mcbsp_io_type_t io_type);
>
> #endif
> diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
> index b6b520d..1212d11 100644
> --- a/arch/arm/plat-omap/mcbsp.c
> +++ b/arch/arm/plat-omap/mcbsp.c
> @@ -425,7 +425,7 @@ void omap_mcbsp_stop(unsigned int id)
> }
> EXPORT_SYMBOL(omap_mcbsp_stop);
>
> -/* polled mcbsp i/o operations */
> +/* polled mcbsp i/o operations for omap1 and omap2420 */
> int omap_mcbsp_pollwrite(unsigned int id, u16 buf)
> {
> struct omap_mcbsp *mcbsp;
> @@ -515,6 +515,96 @@ int omap_mcbsp_pollread(unsigned int id, u16 *buf)
> }
> EXPORT_SYMBOL(omap_mcbsp_pollread);
>
> +/* polled mcbsp i/o operations for omap3 */
> +int omap3_mcbsp_pollwrite(unsigned int id, u32 buf)
> +{
> + struct omap_mcbsp *mcbsp;
> + void __iomem *base;
> +
> + if (!omap_mcbsp_check_valid_id(id)) {
> + printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
> + return -ENODEV;
> + }
> +
> + mcbsp = id_to_mcbsp_ptr(id);
> + base = mcbsp->io_base;
> +
> + OMAP_MCBSP_WRITE(base, DXR, buf);
> + /* if frame sync error - clear the error */
> + if (OMAP_MCBSP_READ(base, SPCR2) & XSYNC_ERR) {
> + /* clear error */
> + OMAP_MCBSP_WRITE(base, SPCR2, OMAP_MCBSP_READ(base, SPCR2)
> + & (~XSYNC_ERR));
> + /* resend */
> + return -EPERM;
> + } else {
> + /* wait for transmit confirmation */
> + int attemps = 0;
> + while (!(OMAP_MCBSP_READ(base, SPCR2) & XRDY)) {
> + if (attemps++ > 1000) {
> + OMAP_MCBSP_WRITE(base, SPCR2,
> + OMAP_MCBSP_READ(base, SPCR2) &
> + (~XRST));
> + udelay(10);
> + OMAP_MCBSP_WRITE(base, SPCR2,
> + OMAP_MCBSP_READ(base, SPCR2) |
> + (XRST));
> + udelay(10);
> + dev_err(mcbsp->dev, "Could not write to"
> + " McBSP%d Register\n", mcbsp->id);
> + return -ENOENT;
> + }
> + }
> + }
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(omap3_mcbsp_pollwrite);
> +
> +int omap3_mcbsp_pollread(unsigned int id, u32 *buf)
> +{
> + struct omap_mcbsp *mcbsp;
> + void __iomem *base;
> +
> + if (!omap_mcbsp_check_valid_id(id)) {
> + printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
> + return -ENODEV;
> + }
> + mcbsp = id_to_mcbsp_ptr(id);
> +
> + base = mcbsp->io_base;
> + /* if frame sync error - clear the error */
> + if (OMAP_MCBSP_READ(base, SPCR1) & RSYNC_ERR) {
> + /* clear error */
> + OMAP_MCBSP_WRITE(base, SPCR1, OMAP_MCBSP_READ(base, SPCR1)
> + & (~RSYNC_ERR));
> + /* resend */
> + return -EPERM;
> + } else {
> + /* wait for recieve confirmation */
> + int attemps = 0;
> + while (!(OMAP_MCBSP_READ(base, SPCR1) & RRDY)) {
> + if (attemps++ > 1000) {
> + OMAP_MCBSP_WRITE(base, SPCR1,
> + OMAP_MCBSP_READ(base, SPCR1) &
> + (~RRST));
> + udelay(10);
> + OMAP_MCBSP_WRITE(base, SPCR1,
> + OMAP_MCBSP_READ(base, SPCR1) |
> + (RRST));
> + udelay(10);
> + dev_err(mcbsp->dev, "Could not read from"
> + " McBSP%d Register\n", mcbsp->id);
> + return -ENOENT;
> + }
> + }
> + }
> + *buf = OMAP_MCBSP_READ(base, DRR);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(omap3_mcbsp_pollread);
> +
> /*
> * IRQ based word transmission.
> */
> --
> 1.6.0.4
>
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