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.
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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