[PATCH v9 10/30] bus: mvebu-mbus: Add new API for the PCIe memory and IO aperture

[Ezequiel Garcia]

We add two optional properties to the MBus DT binding, to encode
the PCIe memory and IO aperture. This allows such information to
be retrieved by -for instance- the pci driver to allocate the
MBus decoding windows.

Correspondingly, and in order to retrieve this information,
we add two new APIs.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia at free-electrons.com>
Tested-by: Andrew Lunn <andrew at lunn.ch>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth at gmail.com>
---
 drivers/bus/mvebu-mbus.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/mbus.h     |  4 ++++
 2 files changed, 53 insertions(+)

diff --git a/drivers/bus/mvebu-mbus.c b/drivers/bus/mvebu-mbus.c
index 78b8c04..929fed1 100644
--- a/drivers/bus/mvebu-mbus.c
+++ b/drivers/bus/mvebu-mbus.c
@@ -142,6 +142,8 @@ struct mvebu_mbus_state {
 	struct dentry *debugfs_root;
 	struct dentry *debugfs_sdram;
 	struct dentry *debugfs_devs;
+	struct resource pcie_mem_aperture;
+	struct resource pcie_io_aperture;
 	const struct mvebu_mbus_soc_data *soc;
 	int hw_io_coherency;
 };
@@ -821,6 +823,20 @@ int mvebu_mbus_del_window(phys_addr_t base, size_t size)
 	return 0;
 }
 
+void mvebu_mbus_get_pcie_mem_aperture(struct resource *res)
+{
+	if (!res)
+		return;
+	*res = mbus_state.pcie_mem_aperture;
+}
+
+void mvebu_mbus_get_pcie_io_aperture(struct resource *res)
+{
+	if (!res)
+		return;
+	*res = mbus_state.pcie_io_aperture;
+}
+
 static __init int mvebu_mbus_debugfs_init(void)
 {
 	struct mvebu_mbus_state *s = &mbus_state;
@@ -1023,6 +1039,35 @@ static int __init mbus_dt_setup(struct mvebu_mbus_state *mbus,
 	return 0;
 }
 
+static void __init mvebu_mbus_get_pcie_resources(struct device_node *np,
+						 struct resource *mem,
+						 struct resource *io)
+{
+	u32 reg[2];
+	int ret;
+
+	/*
+	 * These are optional, so we clear them and they'll
+	 * be zero if they are missing from the DT.
+	 */
+	memset(mem, 0, sizeof(struct resource));
+	memset(io, 0, sizeof(struct resource));
+
+	ret = of_property_read_u32_array(np, "pcie-mem-aperture", reg, ARRAY_SIZE(reg));
+	if (!ret) {
+		mem->start = reg[0];
+		mem->end = mem->start + reg[1];
+		mem->flags = IORESOURCE_MEM;
+	}
+
+	ret = of_property_read_u32_array(np, "pcie-io-aperture", reg, ARRAY_SIZE(reg));
+	if (!ret) {
+		io->start = reg[0];
+		io->end = io->start + reg[1];
+		io->flags = IORESOURCE_IO;
+	}
+}
+
 int __init mvebu_mbus_dt_init(void)
 {
 	struct resource mbuswins_res, sdramwins_res;
@@ -1062,6 +1107,10 @@ int __init mvebu_mbus_dt_init(void)
 		return -EINVAL;
 	}
 
+	/* Get optional pcie-{mem,io}-aperture properties */
+	mvebu_mbus_get_pcie_resources(np, &mbus_state.pcie_mem_aperture,
+					  &mbus_state.pcie_io_aperture);
+
 	ret = mvebu_mbus_common_init(&mbus_state,
 				     mbuswins_res.start,
 				     resource_size(&mbuswins_res),
diff --git a/include/linux/mbus.h b/include/linux/mbus.h
index eadefd6..650bc15 100644
--- a/include/linux/mbus.h
+++ b/include/linux/mbus.h
@@ -11,6 +11,8 @@
 #ifndef __LINUX_MBUS_H
 #define __LINUX_MBUS_H
 
+struct resource;
+
 struct mbus_dram_target_info
 {
 	/*
@@ -59,6 +61,8 @@ static inline const struct mbus_dram_target_info *mv_mbus_dram_info(void)
 }
 #endif
 
+void mvebu_mbus_get_pcie_mem_aperture(struct resource *res);
+void mvebu_mbus_get_pcie_io_aperture(struct resource *res);
 int mvebu_mbus_add_window_remap_flags(const char *devname, phys_addr_t base,
 				      size_t size, phys_addr_t remap,
 				      unsigned int flags);
-- 
1.8.1.5