- arm: added mhu-v2 controller driver

mhu_db fix kfree by using devm_ variant
 - stm32-ipcc: misc cleanup
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Merge tag 'mailbox-v5.11' of git://git.linaro.org/landing-teams/working/fujitsu/integration

Pull mailbox updates from Jassi Brar:

 - arm: added mhu-v2 controller driver

 - arm_mhu_db: fix kfree by using devm_ variant

 - stm32-ipcc: misc cleanup

* tag 'mailbox-v5.11' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: arm_mhuv2: Add driver
  dt-bindings: mailbox : arm,mhuv2: Add bindings
  mailbox: stm32-ipcc: cast void pointers to unsigned long
  mailbox: stm32-ipcc: remove duplicate error message
  mailbox: stm32-ipcc: add COMPILE_TEST dependency
  mailbox: arm_mhu_db: Fix mhu_db_shutdown by replacing kfree with devm_kfree

Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml

@@ -0,0 +1,209 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mailbox/arm,mhuv2.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ARM MHUv2 Mailbox Controller
+
+maintainers:
+  - Tushar Khandelwal <tushar.khandelwal@arm.com>
+  - Viresh Kumar <viresh.kumar@linaro.org>
+
+description: |
+  The Arm Message Handling Unit (MHU) Version 2 is a mailbox controller that has
+  between 1 and 124 channel windows (each 32-bit wide) to provide unidirectional
+  communication with remote processor(s), where the number of channel windows
+  are implementation dependent.
+
+  Given the unidirectional nature of the controller, an MHUv2 mailbox may only
+  be written to or read from. If a pair of MHU controllers is implemented
+  between two processing elements to provide bidirectional communication, these
+  must be specified as two separate mailboxes.
+
+  If the interrupts property is present in device tree node, then its treated as
+  a "receiver" mailbox, otherwise a "sender".
+
+  An MHU controller must be specified along with the supported transport
+  protocols. The transport protocols determine the method of data transmission
+  as well as the number of provided mailbox channels.
+
+  Following are the possible transport protocols.
+
+  - Data-transfer: Each transfer is made of one or more words, using one or more
+    channel windows.
+
+  - Doorbell: Each transfer is made up of single bit flag, using any one of the
+    bits in a channel window. A channel window can support up to 32 doorbells
+    and the entire window shall be used in doorbell protocol.  Optionally, data
+    may be transmitted through a shared memory region, wherein the MHU is used
+    strictly as an interrupt generation mechanism but that is out of the scope
+    of these bindings.
+
+# We need a select here so we don't match all nodes with 'arm,primecell'
+select:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - arm,mhuv2-tx
+          - arm,mhuv2-rx
+  required:
+    - compatible
+
+properties:
+  compatible:
+    oneOf:
+      - description: Sender mode
+        items:
+          - const: arm,mhuv2-tx
+          - const: arm,primecell
+
+      - description: Receiver-mode
+        items:
+          - const: arm,mhuv2-rx
+          - const: arm,primecell
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    description: |
+      The MHUv2 controller always implements an interrupt in the "receiver"
+      mode, while the interrupt in the "sender" mode was not available in the
+      version MHUv2.0, but the later versions do have it.
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    maxItems: 1
+
+  arm,mhuv2-protocols:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    description: |
+      The MHUv2 controller may contain up to 124 channel windows (each 32-bit
+      wide). The hardware and the DT bindings allows any combination of those to
+      be used for various transport protocols.
+
+      This property allows a platform to describe how these channel windows are
+      used in various transport protocols. The entries in this property shall be
+      present as an array of tuples, where each tuple describes details about
+      one of the transport protocol being implemented over some channel
+      window(s).
+
+      The first field of a tuple signifies the transfer protocol, 0 is reserved
+      for doorbell protocol, and 1 is reserved for data-transfer protocol.
+      Using any other value in the first field of a tuple makes it invalid.
+
+      The second field of a tuple signifies the number of channel windows where
+      the protocol would be used and should be set to a non zero value. For
+      doorbell protocol this field signifies the number of 32-bit channel
+      windows that implement the doorbell protocol. For data-transfer protocol,
+      this field signifies the number of 32-bit channel windows that implement
+      the data-transfer protocol.
+
+      The total number of channel windows specified here shouldn't be more than
+      the ones implemented by the platform, though one can specify lesser number
+      of windows here than what the platform implements.
+
+      mhu: mailbox@2b1f0000 {
+          ...
+
+          arm,mhuv2-protocols = <0 2>, <1 1>, <1 5>, <1 7>;
+      }
+
+      The above example defines the protocols of an ARM MHUv2 mailbox
+      controller, where a total of 15 channel windows are used. The first two
+      windows are used in doorbell protocol (64 doorbells), followed by 1, 5 and
+      7 windows (separately) used in data-transfer protocol.
+
+    minItems: 1
+    maxItems: 124
+    items:
+      items:
+        - enum: [ 0, 1 ]
+        - minimum: 0
+          maximum: 124
+
+
+  '#mbox-cells':
+    description: |
+      It is always set to 2. The first argument in the consumers 'mboxes'
+      property represents the channel window group, which may be used in
+      doorbell, or data-transfer protocol, and the second argument (only
+      relevant in doorbell protocol, should be 0 otherwise) represents the
+      doorbell number within the 32 bit wide channel window.
+
+      From the example given above for arm,mhuv2-protocols, here is how a client
+      node can reference them.
+
+      mboxes = <&mhu 0 5>; // Channel Window Group 0, doorbell 5.
+      mboxes = <&mhu 1 7>; // Channel Window Group 1, doorbell 7.
+      mboxes = <&mhu 2 0>; // Channel Window Group 2, data transfer protocol with 1 window.
+      mboxes = <&mhu 3 0>; // Channel Window Group 3, data transfer protocol with 5 windows.
+      mboxes = <&mhu 4 0>; // Channel Window Group 4, data transfer protocol with 7 windows.
+
+    const: 2
+
+if:
+  # Interrupt is compulsory for receiver
+  properties:
+    compatible:
+      contains:
+        const: arm,mhuv2-rx
+then:
+  required:
+    - interrupts
+
+required:
+  - compatible
+  - reg
+  - '#mbox-cells'
+  - arm,mhuv2-protocols
+
+additionalProperties: false
+
+examples:
+  # Multiple transport protocols implemented by the mailbox controllers
+  - |
+    soc {
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        mhu_tx: mailbox@2b1f0000 {
+            #mbox-cells = <2>;
+            compatible = "arm,mhuv2-tx", "arm,primecell";
+            reg = <0 0x2b1f0000 0 0x1000>;
+            clocks = <&clock 0>;
+            clock-names = "apb_pclk";
+            interrupts = <0 45 4>;
+            arm,mhuv2-protocols = <1 5>, <1 2>, <1 5>, <1 7>, <0 2>;
+        };
+
+        mhu_rx: mailbox@2b1f1000 {
+            #mbox-cells = <2>;
+            compatible = "arm,mhuv2-rx", "arm,primecell";
+            reg = <0 0x2b1f1000 0 0x1000>;
+            clocks = <&clock 0>;
+            clock-names = "apb_pclk";
+            interrupts = <0 46 4>;
+            arm,mhuv2-protocols = <1 1>, <1 7>, <0 2>;
+        };
+
+        mhu_client: scb@2e000000 {
+            compatible = "fujitsu,mb86s70-scb-1.0";
+            reg = <0 0x2e000000 0 0x4000>;
+
+            mboxes =
+                     //data-transfer protocol with 5 windows, mhu-tx
+                     <&mhu_tx 2 0>,
+                     //data-transfer protocol with 7 windows, mhu-tx
+                     <&mhu_tx 3 0>,
+                     //doorbell protocol channel 4, doorbell 27, mhu-tx
+                     <&mhu_tx 4 27>,
+                     //data-transfer protocol with 1 window, mhu-rx
+                     <&mhu_rx 0 0>;
+        };
+    };

MAINTAINERS

@@ -10524,6 +10524,15 @@ F:	drivers/mailbox/
 F:	include/linux/mailbox_client.h
 F:	include/linux/mailbox_controller.h
 
+MAILBOX ARM MHUv2
+M:	Viresh Kumar <viresh.kumar@linaro.org>
+M:	Tushar Khandelwal <Tushar.Khandelwal@arm.com>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+F:	drivers/mailbox/arm_mhuv2.c
+F:	include/linux/mailbox/arm_mhuv2_message.h
+F:	Documentation/devicetree/bindings/mailbox/arm,mhuv2.yaml
+
 MAN-PAGES: MANUAL PAGES FOR LINUX -- Sections 2, 3, 4, 5, and 7
 M:	Michael Kerrisk <mtk.manpages@gmail.com>
 L:	linux-man@vger.kernel.org

drivers/mailbox/Kconfig

@@ -16,6 +16,13 @@ config ARM_MHU
 	  The controller has 3 mailbox channels, the last of which can be
 	  used in Secure mode only.
 
+config ARM_MHU_V2
+	tristate "ARM MHUv2 Mailbox"
+	depends on ARM_AMBA
+	help
+	  Say Y here if you want to build the ARM MHUv2 controller driver,
+	  which provides unidirectional mailboxes between processing elements.
+
 config IMX_MBOX
 	tristate "i.MX Mailbox"
 	depends on ARCH_MXC || COMPILE_TEST
@@ -201,7 +208,7 @@ config BCM_FLEXRM_MBOX
 
 config STM32_IPCC
 	tristate "STM32 IPCC Mailbox"
-	depends on MACH_STM32MP157
+	depends on MACH_STM32MP157 || COMPILE_TEST
 	help
 	  Mailbox implementation for STMicroelectonics STM32 family chips
 	  with hardware for Inter-Processor Communication Controller (IPCC)

drivers/mailbox/Makefile

@@ -7,6 +7,8 @@ obj-$(CONFIG_MAILBOX_TEST)	+= mailbox-test.o
 
 obj-$(CONFIG_ARM_MHU)	+= arm_mhu.o arm_mhu_db.o
 
+obj-$(CONFIG_ARM_MHU_V2)	+= arm_mhuv2.o
+
 obj-$(CONFIG_IMX_MBOX)	+= imx-mailbox.o
 
 obj-$(CONFIG_ARMADA_37XX_RWTM_MBOX)	+= armada-37xx-rwtm-mailbox.o

drivers/mailbox/arm_mhu_db.c

@@ -180,7 +180,7 @@ static void mhu_db_shutdown(struct mbox_chan *chan)
 
 	/* Reset channel */
 	mhu_db_mbox_clear_irq(chan);
-	kfree(chan->con_priv);
+	devm_kfree(mbox->dev, chan->con_priv);
 	chan->con_priv = NULL;
 }
 

drivers/mailbox/stm32-ipcc.c

@@ -144,11 +144,11 @@ static irqreturn_t stm32_ipcc_tx_irq(int irq, void *data)
 
 static int stm32_ipcc_send_data(struct mbox_chan *link, void *data)
 {
-	unsigned int chan = (unsigned int)link->con_priv;
+	unsigned long chan = (unsigned long)link->con_priv;
 	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
 					       controller);
 
-	dev_dbg(ipcc->controller.dev, "%s: chan:%d\n", __func__, chan);
+	dev_dbg(ipcc->controller.dev, "%s: chan:%lu\n", __func__, chan);
 
 	/* set channel n occupied */
 	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XSCR,
@@ -163,7 +163,7 @@ static int stm32_ipcc_send_data(struct mbox_chan *link, void *data)
 
 static int stm32_ipcc_startup(struct mbox_chan *link)
 {
-	unsigned int chan = (unsigned int)link->con_priv;
+	unsigned long chan = (unsigned long)link->con_priv;
 	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
 					       controller);
 	int ret;
@@ -183,7 +183,7 @@ static int stm32_ipcc_startup(struct mbox_chan *link)
 
 static void stm32_ipcc_shutdown(struct mbox_chan *link)
 {
-	unsigned int chan = (unsigned int)link->con_priv;
+	unsigned long chan = (unsigned long)link->con_priv;
 	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
 					       controller);
 
@@ -206,7 +206,7 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
 	struct device_node *np = dev->of_node;
 	struct stm32_ipcc *ipcc;
 	struct resource *res;
-	unsigned int i;
+	unsigned long i;
 	int ret;
 	u32 ip_ver;
 	static const char * const irq_name[] = {"rx", "tx"};
@@ -257,9 +257,6 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
 	for (i = 0; i < IPCC_IRQ_NUM; i++) {
 		ipcc->irqs[i] = platform_get_irq_byname(pdev, irq_name[i]);
 		if (ipcc->irqs[i] < 0) {
-			if (ipcc->irqs[i] != -EPROBE_DEFER)
-				dev_err(dev, "no IRQ specified %s\n",
-					irq_name[i]);
 			ret = ipcc->irqs[i];
 			goto err_clk;
 		}
@@ -268,7 +265,7 @@ static int stm32_ipcc_probe(struct platform_device *pdev)
 						irq_thread[i], IRQF_ONESHOT,
 						dev_name(dev), ipcc);
 		if (ret) {
-			dev_err(dev, "failed to request irq %d (%d)\n", i, ret);
+			dev_err(dev, "failed to request irq %lu (%d)\n", i, ret);
 			goto err_clk;
 		}
 	}

include/linux/mailbox/arm_mhuv2_message.h

@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM MHUv2 Mailbox Message
+ *
+ * Copyright (C) 2020 Arm Ltd.
+ * Copyright (C) 2020 Linaro Ltd.
+ */
+
+#ifndef _LINUX_ARM_MHUV2_MESSAGE_H_
+#define _LINUX_ARM_MHUV2_MESSAGE_H_
+
+#include <linux/types.h>
+
+/* Data structure for data-transfer protocol */
+struct arm_mhuv2_mbox_msg {
+	void *data;
+	size_t len;
+};
+
+#endif /* _LINUX_ARM_MHUV2_MESSAGE_H_ */