ARM Keystone SOC driver updates for 4.4

Documentation and support to be able to load the PDSP
 	firmware necessary for accumulator operation.
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Merge tag 'keystone-driver-soc_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone into next/soc

Merge "ARM Keystone SOC driver updates for 4.4" from Santosh Shilimkar:

	Documentation and support to be able to load the PDSP
	firmware necessary for accumulator operation.

* tag 'keystone-driver-soc_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/ssantosh/linux-keystone:
  soc: ti: qmss: make acc queue support optional in the driver
  soc: ti: add firmware file name as part of the driver
  Documentation: dt: soc: Add description for knav qmss driver

Documentation/arm/keystone/knav-qmss.txt

@@ -0,0 +1,56 @@
+* Texas Instruments Keystone Navigator Queue Management SubSystem driver
+
+Driver source code path
+  drivers/soc/ti/knav_qmss.c
+  drivers/soc/ti/knav_qmss_acc.c
+
+The QMSS (Queue Manager Sub System) found on Keystone SOCs is one of
+the main hardware sub system which forms the backbone of the Keystone
+multi-core Navigator. QMSS consist of queue managers, packed-data structure
+processors(PDSP), linking RAM, descriptor pools and infrastructure
+Packet DMA.
+The Queue Manager is a hardware module that is responsible for accelerating
+management of the packet queues. Packets are queued/de-queued by writing or
+reading descriptor address to a particular memory mapped location. The PDSPs
+perform QMSS related functions like accumulation, QoS, or event management.
+Linking RAM registers are used to link the descriptors which are stored in
+descriptor RAM. Descriptor RAM is configurable as internal or external memory.
+The QMSS driver manages the PDSP setups, linking RAM regions,
+queue pool management (allocation, push, pop and notify) and descriptor
+pool management.
+
+knav qmss driver provides a set of APIs to drivers to open/close qmss queues,
+allocate descriptor pools, map the descriptors, push/pop to queues etc. For
+details of the available APIs, please refers to include/linux/soc/ti/knav_qmss.h
+
+DT documentation is available at
+Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt
+
+Accumulator QMSS queues using PDSP firmware
+============================================
+The QMSS PDSP firmware support accumulator channel that can monitor a single
+queue or multiple contiguous queues. drivers/soc/ti/knav_qmss_acc.c is the
+driver that interface with the accumulator PDSP. This configures
+accumulator channels defined in DTS (example in DT documentation) to monitor
+1 or 32 queues per channel. More description on the firmware is available in
+CPPI/QMSS Low Level Driver document (docs/CPPI_QMSS_LLD_SDS.pdf) at
+	git://git.ti.com/keystone-rtos/qmss-lld.git
+
+k2_qmss_pdsp_acc48_k2_le_1_0_0_9.bin firmware supports upto 48 accumulator
+channels. This firmware is available under ti-keystone folder of
+firmware.git at
+   git://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git
+
+To use copy the firmware image to lib/firmware folder of the initramfs or
+ubifs file system and provide a sym link to k2_qmss_pdsp_acc48_k2_le_1_0_0_9.bin
+in the file system and boot up the kernel. User would see
+
+ "firmware file ks2_qmss_pdsp_acc48.bin downloaded for PDSP"
+
+in the boot up log if loading of firmware to PDSP is successful.
+
+Use of accumulated queues requires the firmware image to be present in the
+file system. The driver doesn't acc queues to the supported queue range if
+PDSP is not running in the SoC. The API call fails if there is a queue open
+request to an acc queue and PDSP is not running. So make sure to copy firmware
+to file system before using these queue types.

Documentation/devicetree/bindings/soc/ti/keystone-navigator-qmss.txt

@@ -221,7 +221,6 @@ qmss: qmss@2a40000 {
 		#size-cells = <1>;
 		ranges;
 		pdsp0@0x2a10000 {
-			firmware = "keystone/qmss_pdsp_acc48_k2_le_1_0_0_8.fw";
 			reg = <0x2a10000 0x1000>,
 			      <0x2a0f000 0x100>,
 			      <0x2a0c000 0x3c8>,

drivers/soc/ti/knav_qmss.h

@@ -135,9 +135,10 @@ struct knav_pdsp_info {
 	};
 	void __iomem					*intd;
 	u32 __iomem					*iram;
-	const char					*firmware;
 	u32						id;
 	struct list_head				list;
+	bool						loaded;
+	bool						started;
 };
 
 struct knav_qmgr_info {

drivers/soc/ti/knav_qmss_acc.c

@@ -482,8 +482,8 @@ struct knav_range_ops knav_acc_range_ops = {
  * Return 0 on success or error
  */
 int knav_init_acc_range(struct knav_device *kdev,
-				struct device_node *node,
-				struct knav_range_info *range)
+			struct device_node *node,
+			struct knav_range_info *range)
 {
 	struct knav_acc_channel *acc;
 	struct knav_pdsp_info *pdsp;
@@ -526,6 +526,12 @@ int knav_init_acc_range(struct knav_device *kdev,
 		return -EINVAL;
 	}
 
+	if (!pdsp->started) {
+		dev_err(kdev->dev, "pdsp id %d not started for range %s\n",
+			info->pdsp_id, range->name);
+		return -ENODEV;
+	}
+
 	info->pdsp = pdsp;
 	channels = range->num_queues;
 	if (of_get_property(node, "multi-queue", NULL)) {

drivers/soc/ti/knav_qmss_queue.c

@@ -68,6 +68,12 @@ static DEFINE_MUTEX(knav_dev_lock);
 	     idx < (kdev)->num_queues_in_use;			\
 	     idx++, inst = knav_queue_idx_to_inst(kdev, idx))
 
+/* All firmware file names end up here. List the firmware file names below.
+ * Newest followed by older ones. Search is done from start of the array
+ * until a firmware file is found.
+ */
+const char *knav_acc_firmwares[] = {"ks2_qmss_pdsp_acc48.bin"};
+
 /**
  * knav_queue_notify: qmss queue notfier call
  *
@@ -1439,7 +1445,6 @@ static int knav_queue_init_pdsps(struct knav_device *kdev,
 	struct device *dev = kdev->dev;
 	struct knav_pdsp_info *pdsp;
 	struct device_node *child;
-	int ret;
 
 	for_each_child_of_node(pdsps, child) {
 		pdsp = devm_kzalloc(dev, sizeof(*pdsp), GFP_KERNEL);
@@ -1448,17 +1453,6 @@ static int knav_queue_init_pdsps(struct knav_device *kdev,
 			return -ENOMEM;
 		}
 		pdsp->name = knav_queue_find_name(child);
-		ret = of_property_read_string(child, "firmware",
-					      &pdsp->firmware);
-		if (ret < 0 || !pdsp->firmware) {
-			dev_err(dev, "unknown firmware for pdsp %s\n",
-				pdsp->name);
-			devm_kfree(dev, pdsp);
-			continue;
-		}
-		dev_dbg(dev, "pdsp name %s fw name :%s\n", pdsp->name,
-			pdsp->firmware);
-
 		pdsp->iram =
 			knav_queue_map_reg(kdev, child,
 					   KNAV_QUEUE_PDSP_IRAM_REG_INDEX);
@@ -1489,9 +1483,9 @@ static int knav_queue_init_pdsps(struct knav_device *kdev,
 		}
 		of_property_read_u32(child, "id", &pdsp->id);
 		list_add_tail(&pdsp->list, &kdev->pdsps);
-		dev_dbg(dev, "added pdsp %s: command %p, iram %p, regs %p, intd %p, firmware %s\n",
+		dev_dbg(dev, "added pdsp %s: command %p, iram %p, regs %p, intd %p\n",
 			pdsp->name, pdsp->command, pdsp->iram, pdsp->regs,
-			pdsp->intd, pdsp->firmware);
+			pdsp->intd);
 	}
 	return 0;
 }
@@ -1510,6 +1504,8 @@ static int knav_queue_stop_pdsp(struct knav_device *kdev,
 		dev_err(kdev->dev, "timed out on pdsp %s stop\n", pdsp->name);
 		return ret;
 	}
+	pdsp->loaded = false;
+	pdsp->started = false;
 	return 0;
 }
 
@@ -1518,14 +1514,29 @@ static int knav_queue_load_pdsp(struct knav_device *kdev,
 {
 	int i, ret, fwlen;
 	const struct firmware *fw;
+	bool found = false;
 	u32 *fwdata;
 
-	ret = request_firmware(&fw, pdsp->firmware, kdev->dev);
-	if (ret) {
-		dev_err(kdev->dev, "failed to get firmware %s for pdsp %s\n",
-			pdsp->firmware, pdsp->name);
-		return ret;
+	for (i = 0; i < ARRAY_SIZE(knav_acc_firmwares); i++) {
+		if (knav_acc_firmwares[i]) {
+			ret = request_firmware(&fw,
+					       knav_acc_firmwares[i],
+					       kdev->dev);
+			if (!ret) {
+				found = true;
+				break;
+			}
+		}
 	}
+
+	if (!found) {
+		dev_err(kdev->dev, "failed to get firmware for pdsp\n");
+		return -ENODEV;
+	}
+
+	dev_info(kdev->dev, "firmware file %s downloaded for PDSP\n",
+		 knav_acc_firmwares[i]);
+
 	writel_relaxed(pdsp->id + 1, pdsp->command + 0x18);
 	/* download the firmware */
 	fwdata = (u32 *)fw->data;
@@ -1583,16 +1594,24 @@ static int knav_queue_start_pdsps(struct knav_device *kdev)
 	int ret;
 
 	knav_queue_stop_pdsps(kdev);
-	/* now load them all */
+	/* now load them all. We return success even if pdsp
+	 * is not loaded as acc channels are optional on having
+	 * firmware availability in the system. We set the loaded
+	 * and stated flag and when initialize the acc range, check
+	 * it and init the range only if pdsp is started.
+	 */
 	for_each_pdsp(kdev, pdsp) {
 		ret = knav_queue_load_pdsp(kdev, pdsp);
-		if (ret < 0)
-			return ret;
+		if (!ret)
+			pdsp->loaded = true;
 	}
 
 	for_each_pdsp(kdev, pdsp) {
-		ret = knav_queue_start_pdsp(kdev, pdsp);
-		WARN_ON(ret);
+		if (pdsp->loaded) {
+			ret = knav_queue_start_pdsp(kdev, pdsp);
+			if (!ret)
+				pdsp->started = true;
+		}
 	}
 	return 0;
 }