soc: qcom: ipa: main code

This patch includes three source files that represent some basic "main
program" code for the IPA driver.  They are:
  - "ipa.h" defines the top-level IPA structure which represents an IPA
     device throughout the code.
  - "ipa_main.c" contains the platform driver probe function, along with
    some general code used during initialization.
  - "ipa_reg.h" defines the offsets of the 32-bit registers used for the
    IPA device, along with masks that define the position and width of
    fields within these registers.
  - "version.h" defines some symbolic IPA version numbers.

Each file includes some documentation that provides a little more
overview of how the code is organized and used.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ipa/ipa.h

+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2018-2020 Linaro Ltd.
+ */
+#ifndef _IPA_H_
+#define _IPA_H_
+
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/notifier.h>
+#include <linux/pm_wakeup.h>
+
+#include "ipa_version.h"
+#include "gsi.h"
+#include "ipa_mem.h"
+#include "ipa_qmi.h"
+#include "ipa_endpoint.h"
+#include "ipa_interrupt.h"
+
+struct clk;
+struct icc_path;
+struct net_device;
+struct platform_device;
+
+struct ipa_clock;
+struct ipa_smp2p;
+struct ipa_interrupt;
+
+/**
+ * struct ipa - IPA information
+ * @gsi:		Embedded GSI structure
+ * @version:		IPA hardware version
+ * @pdev:		Platform device
+ * @modem_rproc:	Remoteproc handle for modem subsystem
+ * @smp2p:		SMP2P information
+ * @clock:		IPA clocking information
+ * @suspend_ref:	Whether clock reference preventing suspend taken
+ * @table_addr:		DMA address of filter/route table content
+ * @table_virt:		Virtual address of filter/route table content
+ * @interrupt:		IPA Interrupt information
+ * @uc_loaded:		true after microcontroller has reported it's ready
+ * @reg_addr:		DMA address used for IPA register access
+ * @reg_virt:		Virtual address used for IPA register access
+ * @mem_addr:		DMA address of IPA-local memory space
+ * @mem_virt:		Virtual address of IPA-local memory space
+ * @mem_offset:		Offset from @mem_virt used for access to IPA memory
+ * @mem_size:		Total size (bytes) of memory at @mem_virt
+ * @mem:		Array of IPA-local memory region descriptors
+ * @zero_addr:		DMA address of preallocated zero-filled memory
+ * @zero_virt:		Virtual address of preallocated zero-filled memory
+ * @zero_size:		Size (bytes) of preallocated zero-filled memory
+ * @wakeup_source:	Wakeup source information
+ * @available:		Bit mask indicating endpoints hardware supports
+ * @filter_map:		Bit mask indicating endpoints that support filtering
+ * @initialized:	Bit mask indicating endpoints initialized
+ * @set_up:		Bit mask indicating endpoints set up
+ * @enabled:		Bit mask indicating endpoints enabled
+ * @endpoint:		Array of endpoint information
+ * @channel_map:	Mapping of GSI channel to IPA endpoint
+ * @name_map:		Mapping of IPA endpoint name to IPA endpoint
+ * @setup_complete:	Flag indicating whether setup stage has completed
+ * @modem_state:	State of modem (stopped, running)
+ * @modem_netdev:	Network device structure used for modem
+ * @qmi:		QMI information
+ */
+struct ipa {
+	struct gsi gsi;
+	enum ipa_version version;
+	struct platform_device *pdev;
+	struct rproc *modem_rproc;
+	struct ipa_smp2p *smp2p;
+	struct ipa_clock *clock;
+	atomic_t suspend_ref;
+
+	dma_addr_t table_addr;
+	__le64 *table_virt;
+
+	struct ipa_interrupt *interrupt;
+	bool uc_loaded;
+
+	dma_addr_t reg_addr;
+	void __iomem *reg_virt;
+
+	dma_addr_t mem_addr;
+	void *mem_virt;
+	u32 mem_offset;
+	u32 mem_size;
+	const struct ipa_mem *mem;
+
+	dma_addr_t zero_addr;
+	void *zero_virt;
+	size_t zero_size;
+
+	struct wakeup_source *wakeup_source;
+
+	/* Bit masks indicating endpoint state */
+	u32 available;		/* supported by hardware */
+	u32 filter_map;
+	u32 initialized;
+	u32 set_up;
+	u32 enabled;
+
+	struct ipa_endpoint endpoint[IPA_ENDPOINT_MAX];
+	struct ipa_endpoint *channel_map[GSI_CHANNEL_COUNT_MAX];
+	struct ipa_endpoint *name_map[IPA_ENDPOINT_COUNT];
+
+	bool setup_complete;
+
+	atomic_t modem_state;		/* enum ipa_modem_state */
+	struct net_device *modem_netdev;
+	struct ipa_qmi qmi;
+};
+
+/**
+ * ipa_setup() - Perform IPA setup
+ * @ipa:		IPA pointer
+ *
+ * IPA initialization is broken into stages:  init; config; and setup.
+ * (These have inverses exit, deconfig, and teardown.)
+ *
+ * Activities performed at the init stage can be done without requiring
+ * any access to IPA hardware.  Activities performed at the config stage
+ * require the IPA clock to be running, because they involve access
+ * to IPA registers.  The setup stage is performed only after the GSI
+ * hardware is ready (more on this below).  The setup stage allows
+ * the AP to perform more complex initialization by issuing "immediate
+ * commands" using a special interface to the IPA.
+ *
+ * This function, @ipa_setup(), starts the setup stage.
+ *
+ * In order for the GSI hardware to be functional it needs firmware to be
+ * loaded (in addition to some other low-level initialization).  This early
+ * GSI initialization can be done either by Trust Zone on the AP or by the
+ * modem.
+ *
+ * If it's done by Trust Zone, the AP loads the GSI firmware and supplies
+ * it to Trust Zone to verify and install.  When this completes, if
+ * verification was successful, the GSI layer is ready and ipa_setup()
+ * implements the setup phase of initialization.
+ *
+ * If the modem performs early GSI initialization, the AP needs to know
+ * when this has occurred.  An SMP2P interrupt is used for this purpose,
+ * and receipt of that interrupt triggers the call to ipa_setup().
+ */
+int ipa_setup(struct ipa *ipa);
+
+#endif /* _IPA_H_ */

drivers/net/ipa/ipa_reg.c

+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+
+#include <linux/io.h>
+
+#include "ipa.h"
+#include "ipa_reg.h"
+
+int ipa_reg_init(struct ipa *ipa)
+{
+	struct device *dev = &ipa->pdev->dev;
+	struct resource *res;
+
+	/* Setup IPA register memory  */
+	res = platform_get_resource_byname(ipa->pdev, IORESOURCE_MEM,
+					   "ipa-reg");
+	if (!res) {
+		dev_err(dev, "DT error getting \"ipa-reg\" memory property\n");
+		return -ENODEV;
+	}
+
+	ipa->reg_virt = ioremap(res->start, resource_size(res));
+	if (!ipa->reg_virt) {
+		dev_err(dev, "unable to remap \"ipa-reg\" memory\n");
+		return -ENOMEM;
+	}
+	ipa->reg_addr = res->start;
+
+	return 0;
+}
+
+void ipa_reg_exit(struct ipa *ipa)
+{
+	iounmap(ipa->reg_virt);
+}

drivers/net/ipa/ipa_version.h

+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+#ifndef _IPA_VERSION_H_
+#define _IPA_VERSION_H_
+
+/**
+ * enum ipa_version
+ *
+ * Defines the version of IPA (and GSI) hardware present on the platform.
+ * It seems this might be better defined elsewhere, but having it here gets
+ * it where it's needed.
+ */
+enum ipa_version {
+	IPA_VERSION_3_5_1,	/* GSI version 1.3.0 */
+	IPA_VERSION_4_0,	/* GSI version 2.0 */
+	IPA_VERSION_4_1,	/* GSI version 2.1 */
+	IPA_VERSION_4_2,	/* GSI version 2.2 */
+};
+
+#endif /* _IPA_VERSION_H_ */