tspp: Add option to read TSIF clock reference counter
Reading the current value of TSIF clock reference counter
is required by some application.
Change-Id: I0fceb46ee50b8c76674ea9b8169e0b31f63fba3d
Signed-off-by: Hamad Kadmany <hkadmany@codeaurora.org>
diff --git a/arch/arm/mach-msm/include/mach/msm_tspp.h b/arch/arm/mach-msm/include/mach/msm_tspp.h
index a024a99..696d4ef 100644
--- a/arch/arm/mach-msm/include/mach/msm_tspp.h
+++ b/arch/arm/mach-msm/include/mach/msm_tspp.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011-2012, Code Aurora Forum. All rights reserved.
+/* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@@ -42,6 +42,8 @@
int tspp_close_stream(u32 dev, u32 channel_id);
int tspp_open_channel(u32 dev, u32 channel_id);
int tspp_close_channel(u32 dev, u32 channel_id);
+int tspp_get_ref_clk_counter(u32 dev,
+ enum tspp_source source, u32 *tcr_counter);
int tspp_add_filter(u32 dev, u32 channel_id, struct tspp_filter *filter);
int tspp_remove_filter(u32 dev, u32 channel_id, struct tspp_filter *filter);
int tspp_set_key(u32 dev, u32 channel_id, struct tspp_key *key);
diff --git a/drivers/misc/tspp.c b/drivers/misc/tspp.c
index 563a013..0715d6d 100644
--- a/drivers/misc/tspp.c
+++ b/drivers/misc/tspp.c
@@ -1613,6 +1613,55 @@
EXPORT_SYMBOL(tspp_close_channel);
/**
+ * tspp_get_ref_clk_counter - return the TSIF clock reference (TCR) counter.
+ *
+ * @dev: TSPP device (up to TSPP_MAX_DEVICES)
+ * @source: The TSIF source from which the counter should be read
+ * @tcr_counter: the value of TCR counter
+ *
+ * Return error status
+ *
+ * TCR increments at a rate equal to 27 MHz/256 = 105.47 kHz.
+ * If source is neither TSIF 0 or TSIF1 0 is returned.
+ */
+int tspp_get_ref_clk_counter(u32 dev, enum tspp_source source, u32 *tcr_counter)
+{
+ struct tspp_device *pdev;
+ struct tspp_tsif_device *tsif_device;
+
+ if (!tcr_counter)
+ return -EINVAL;
+
+ pdev = tspp_find_by_id(dev);
+ if (!pdev) {
+ pr_err("tspp_get_ref_clk_counter: can't find device %i\n", dev);
+ return -ENODEV;
+ }
+
+ switch (source) {
+ case TSPP_SOURCE_TSIF0:
+ tsif_device = &pdev->tsif[0];
+ break;
+
+ case TSPP_SOURCE_TSIF1:
+ tsif_device = &pdev->tsif[1];
+ break;
+
+ default:
+ tsif_device = NULL;
+ break;
+ }
+
+ if (tsif_device && tsif_device->ref_count)
+ *tcr_counter = ioread32(tsif_device->base + TSIF_CLK_REF_OFF);
+ else
+ *tcr_counter = 0;
+
+ return 0;
+}
+EXPORT_SYMBOL(tspp_get_ref_clk_counter);
+
+/**
* tspp_add_filter - add a TSPP filter to a channel.
*
* @dev: TSPP device (up to TSPP_MAX_DEVICES)