ARM: OMAP: mcbsp: Make threshold based transfer code generic

Remove CONFIG_ARCH_OMAP3 conditional compilation and cpu_is_omap34xx test
around buffer threshold based transfer and DMA operating mode control. Use
instead the buffer_size in platform data to determine when these sysfs
controls are exposed and when to access related McBSP registers. Rationale
for this is to make code generic and to allow to use it on OMAP4 that also
supports threshold based transfers.

Currently buffer_size variable is set only for OMAP3 SoCs but it is easy
to extend to OMAP4 and any later OMAP version.

Signed-off-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
index 97bcbfa..234ab16 100644
--- a/arch/arm/plat-omap/mcbsp.c
+++ b/arch/arm/plat-omap/mcbsp.c
@@ -492,6 +492,11 @@
 }
 EXPORT_SYMBOL(omap_st_is_enabled);
 
+#else
+static inline void omap_st_start(struct omap_mcbsp *mcbsp) {}
+static inline void omap_st_stop(struct omap_mcbsp *mcbsp) {}
+#endif
+
 /*
  * omap_mcbsp_set_rx_threshold configures the transmit threshold in words.
  * The threshold parameter is 1 based, and it is converted (threshold - 1)
@@ -501,14 +506,13 @@
 {
 	struct omap_mcbsp *mcbsp;
 
-	if (!cpu_is_omap34xx() && !cpu_is_omap44xx())
-		return;
-
 	if (!omap_mcbsp_check_valid_id(id)) {
 		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
 		return;
 	}
 	mcbsp = id_to_mcbsp_ptr(id);
+	if (mcbsp->pdata->buffer_size == 0)
+		return;
 
 	if (threshold && threshold <= mcbsp->max_tx_thres)
 		MCBSP_WRITE(mcbsp, THRSH2, threshold - 1);
@@ -524,14 +528,13 @@
 {
 	struct omap_mcbsp *mcbsp;
 
-	if (!cpu_is_omap34xx() && !cpu_is_omap44xx())
-		return;
-
 	if (!omap_mcbsp_check_valid_id(id)) {
 		printk(KERN_ERR "%s: Invalid id (%d)\n", __func__, id + 1);
 		return;
 	}
 	mcbsp = id_to_mcbsp_ptr(id);
+	if (mcbsp->pdata->buffer_size == 0)
+		return;
 
 	if (threshold && threshold <= mcbsp->max_rx_thres)
 		MCBSP_WRITE(mcbsp, THRSH1, threshold - 1);
@@ -601,6 +604,8 @@
 		return -ENODEV;
 	}
 	mcbsp = id_to_mcbsp_ptr(id);
+	if (mcbsp->pdata->buffer_size == 0)
+		return 0;
 
 	/* Returns the number of free locations in the buffer */
 	buffstat = MCBSP_READ(mcbsp, XBUFFSTAT);
@@ -624,6 +629,8 @@
 		return -ENODEV;
 	}
 	mcbsp = id_to_mcbsp_ptr(id);
+	if (mcbsp->pdata->buffer_size == 0)
+		return 0;
 
 	/* Returns the number of used locations in the buffer */
 	buffstat = MCBSP_READ(mcbsp, RBUFFSTAT);
@@ -659,11 +666,6 @@
 }
 EXPORT_SYMBOL(omap_mcbsp_get_dma_op_mode);
 
-#else
-static inline void omap_st_start(struct omap_mcbsp *mcbsp) {}
-static inline void omap_st_stop(struct omap_mcbsp *mcbsp) {}
-#endif
-
 int omap_mcbsp_request(unsigned int id)
 {
 	struct omap_mcbsp *mcbsp;
@@ -937,7 +939,6 @@
 }
 #endif
 
-#ifdef CONFIG_ARCH_OMAP3
 #define max_thres(m)			(mcbsp->pdata->buffer_size)
 #define valid_threshold(m, val)		((val) <= max_thres(m))
 #define THRESHOLD_PROP_BUILDER(prop)					\
@@ -1028,6 +1029,18 @@
 
 static DEVICE_ATTR(dma_op_mode, 0644, dma_op_mode_show, dma_op_mode_store);
 
+static const struct attribute *additional_attrs[] = {
+	&dev_attr_max_tx_thres.attr,
+	&dev_attr_max_rx_thres.attr,
+	&dev_attr_dma_op_mode.attr,
+	NULL,
+};
+
+static const struct attribute_group additional_attr_group = {
+	.attrs = (struct attribute **)additional_attrs,
+};
+
+#ifdef CONFIG_ARCH_OMAP3
 static ssize_t st_taps_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {
@@ -1086,27 +1099,6 @@
 
 static DEVICE_ATTR(st_taps, 0644, st_taps_show, st_taps_store);
 
-static const struct attribute *additional_attrs[] = {
-	&dev_attr_max_tx_thres.attr,
-	&dev_attr_max_rx_thres.attr,
-	&dev_attr_dma_op_mode.attr,
-	NULL,
-};
-
-static const struct attribute_group additional_attr_group = {
-	.attrs = (struct attribute **)additional_attrs,
-};
-
-static inline int __devinit omap_additional_add(struct device *dev)
-{
-	return sysfs_create_group(&dev->kobj, &additional_attr_group);
-}
-
-static inline void __devexit omap_additional_remove(struct device *dev)
-{
-	sysfs_remove_group(&dev->kobj, &additional_attr_group);
-}
-
 static const struct attribute *sidetone_attrs[] = {
 	&dev_attr_st_taps.attr,
 	NULL,
@@ -1167,45 +1159,18 @@
 
 static inline void __devinit omap34xx_device_init(struct omap_mcbsp *mcbsp)
 {
-	mcbsp->dma_op_mode = MCBSP_DMA_MODE_ELEMENT;
-	if (cpu_is_omap34xx()) {
-		/*
-		 * Initially configure the maximum thresholds to a safe value.
-		 * The McBSP FIFO usage with these values should not go under
-		 * 16 locations.
-		 * If the whole FIFO without safety buffer is used, than there
-		 * is a possibility that the DMA will be not able to push the
-		 * new data on time, causing channel shifts in runtime.
-		 */
-		mcbsp->max_tx_thres = max_thres(mcbsp) - 0x10;
-		mcbsp->max_rx_thres = max_thres(mcbsp) - 0x10;
-		/*
-		 * REVISIT: Set dmap_op_mode to THRESHOLD as default
-		 * for mcbsp2 instances.
-		 */
-		if (omap_additional_add(mcbsp->dev))
-			dev_warn(mcbsp->dev,
-				"Unable to create additional controls\n");
-
+	if (cpu_is_omap34xx())
 		if (mcbsp->id == 2 || mcbsp->id == 3)
 			if (omap_st_add(mcbsp))
 				dev_warn(mcbsp->dev,
 				 "Unable to create sidetone controls\n");
-
-	} else {
-		mcbsp->max_tx_thres = -EINVAL;
-		mcbsp->max_rx_thres = -EINVAL;
-	}
 }
 
 static inline void __devexit omap34xx_device_exit(struct omap_mcbsp *mcbsp)
 {
-	if (cpu_is_omap34xx()) {
-		omap_additional_remove(mcbsp->dev);
-
+	if (cpu_is_omap34xx())
 		if (mcbsp->id == 2 || mcbsp->id == 3)
 			omap_st_remove(mcbsp);
-	}
 }
 #else
 static inline void __devinit omap34xx_device_init(struct omap_mcbsp *mcbsp) {}
@@ -1311,11 +1276,38 @@
 	platform_set_drvdata(pdev, mcbsp);
 	pm_runtime_enable(mcbsp->dev);
 
+	mcbsp->dma_op_mode = MCBSP_DMA_MODE_ELEMENT;
+	if (mcbsp->pdata->buffer_size) {
+		/*
+		 * Initially configure the maximum thresholds to a safe value.
+		 * The McBSP FIFO usage with these values should not go under
+		 * 16 locations.
+		 * If the whole FIFO without safety buffer is used, than there
+		 * is a possibility that the DMA will be not able to push the
+		 * new data on time, causing channel shifts in runtime.
+		 */
+		mcbsp->max_tx_thres = max_thres(mcbsp) - 0x10;
+		mcbsp->max_rx_thres = max_thres(mcbsp) - 0x10;
+
+		ret = sysfs_create_group(&mcbsp->dev->kobj,
+					 &additional_attr_group);
+		if (ret) {
+			dev_err(mcbsp->dev,
+				"Unable to create additional controls\n");
+			goto err_thres;
+		}
+	} else {
+		mcbsp->max_tx_thres = -EINVAL;
+		mcbsp->max_rx_thres = -EINVAL;
+	}
+
 	/* Initialize mcbsp properties for OMAP34XX if needed / applicable */
 	omap34xx_device_init(mcbsp);
 
 	return 0;
 
+err_thres:
+	clk_put(mcbsp->fclk);
 err_res:
 	iounmap(mcbsp->io_base);
 err_ioremap:
@@ -1335,6 +1327,10 @@
 				mcbsp->pdata->ops->free)
 			mcbsp->pdata->ops->free(mcbsp->id);
 
+		if (mcbsp->pdata->buffer_size)
+			sysfs_remove_group(&mcbsp->dev->kobj,
+					   &additional_attr_group);
+
 		omap34xx_device_exit(mcbsp);
 
 		clk_put(mcbsp->fclk);