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Commit 4749c02b authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Jason Cooper
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bus: mvebu-mbus: provide a mechanism to save SDRAM window configuration 



On Marvell EBU platforms, when doing suspend/resume, the SDRAM window
configuration must be saved on suspend, and restored on
resume. However, it needs to be restored on resume *before*
re-entering the kernel, because the SDRAM window configuration defines
the layout of the memory. For this reason, it cannot simply be done in
the ->suspend() and ->resume() hooks of the mvebu-mbus driver.

Instead, it needs to be restored by the bootloader "boot info"
mechanism used when resuming. This mechanism allows the kernel to
define a list of (address, value) pairs when suspending, that the
bootloader will restore on resume before jumping back into the kernel.

This commit therefore adds a new function to the mvebu-mbus driver,
called mvebu_mbus_save_cpu_target(), which will be called by the
platform code to make the mvebu-mbus driver save the SDRAM window
configuration in a way that can be understood by the bootloader "boot
info" mechanism.

Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Reviewed-by: default avatarGregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1416585613-2113-8-git-send-email-thomas.petazzoni@free-electrons.com


Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
parent a0e89c02

drivers/bus/mvebu-mbus.c

+56 −0
Original line number Diff line number Diff line
@@ -110,6 +110,8 @@ struct mvebu_mbus_soc_data { 
	bool has_mbus_bridge;

	unsigned int (*win_cfg_offset)(const int win);

	void (*setup_cpu_target)(struct mvebu_mbus_state *s);

	int (*save_cpu_target)(struct mvebu_mbus_state *s,

			       u32 *store_addr);

	int (*show_cpu_target)(struct mvebu_mbus_state *s,

			       struct seq_file *seq, void *v);

};
@@ -128,6 +130,7 @@ struct mvebu_mbus_state { 
	void __iomem *mbuswins_base;

	void __iomem *sdramwins_base;

	void __iomem *mbusbridge_base;

	phys_addr_t sdramwins_phys_base;

	struct dentry *debugfs_root;

	struct dentry *debugfs_sdram;

	struct dentry *debugfs_devs;
@@ -541,6 +544,28 @@ mvebu_mbus_default_setup_cpu_target(struct mvebu_mbus_state *mbus) 
	mvebu_mbus_dram_info.num_cs = cs;

}



static int

mvebu_mbus_default_save_cpu_target(struct mvebu_mbus_state *mbus,

				   u32 *store_addr)

{

	int i;



	for (i = 0; i < 4; i++) {

		u32 base = readl(mbus->sdramwins_base + DDR_BASE_CS_OFF(i));

		u32 size = readl(mbus->sdramwins_base + DDR_SIZE_CS_OFF(i));



		writel(mbus->sdramwins_phys_base + DDR_BASE_CS_OFF(i),

		       store_addr++);

		writel(base, store_addr++);

		writel(mbus->sdramwins_phys_base + DDR_SIZE_CS_OFF(i),

		       store_addr++);

		writel(size, store_addr++);

	}



	/* We've written 16 words to the store address */

	return 16;

}



static void __init

mvebu_mbus_dove_setup_cpu_target(struct mvebu_mbus_state *mbus)

{
@@ -571,11 +596,35 @@ mvebu_mbus_dove_setup_cpu_target(struct mvebu_mbus_state *mbus) 
	mvebu_mbus_dram_info.num_cs = cs;

}



static int

mvebu_mbus_dove_save_cpu_target(struct mvebu_mbus_state *mbus,

				u32 *store_addr)

{

	int i;



	for (i = 0; i < 2; i++) {

		u32 map = readl(mbus->sdramwins_base + DOVE_DDR_BASE_CS_OFF(i));



		writel(mbus->sdramwins_phys_base + DOVE_DDR_BASE_CS_OFF(i),

		       store_addr++);

		writel(map, store_addr++);

	}



	/* We've written 4 words to the store address */

	return 4;

}



int mvebu_mbus_save_cpu_target(u32 *store_addr)

{

	return mbus_state.soc->save_cpu_target(&mbus_state, store_addr);

}



static const struct mvebu_mbus_soc_data armada_370_xp_mbus_data = {

	.num_wins            = 20,

	.num_remappable_wins = 8,

	.has_mbus_bridge     = true,

	.win_cfg_offset      = armada_370_xp_mbus_win_offset,

	.save_cpu_target     = mvebu_mbus_default_save_cpu_target,

	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,

	.show_cpu_target     = mvebu_sdram_debug_show_orion,

};
@@ -584,6 +633,7 @@ static const struct mvebu_mbus_soc_data kirkwood_mbus_data = { 
	.num_wins            = 8,

	.num_remappable_wins = 4,

	.win_cfg_offset      = orion_mbus_win_offset,

	.save_cpu_target     = mvebu_mbus_default_save_cpu_target,

	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,

	.show_cpu_target     = mvebu_sdram_debug_show_orion,

};
@@ -592,6 +642,7 @@ static const struct mvebu_mbus_soc_data dove_mbus_data = { 
	.num_wins            = 8,

	.num_remappable_wins = 4,

	.win_cfg_offset      = orion_mbus_win_offset,

	.save_cpu_target     = mvebu_mbus_dove_save_cpu_target,

	.setup_cpu_target    = mvebu_mbus_dove_setup_cpu_target,

	.show_cpu_target     = mvebu_sdram_debug_show_dove,

};
@@ -604,6 +655,7 @@ static const struct mvebu_mbus_soc_data orion5x_4win_mbus_data = { 
	.num_wins            = 8,

	.num_remappable_wins = 4,

	.win_cfg_offset      = orion_mbus_win_offset,

	.save_cpu_target     = mvebu_mbus_default_save_cpu_target,

	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,

	.show_cpu_target     = mvebu_sdram_debug_show_orion,

};
@@ -612,6 +664,7 @@ static const struct mvebu_mbus_soc_data orion5x_2win_mbus_data = { 
	.num_wins            = 8,

	.num_remappable_wins = 2,

	.win_cfg_offset      = orion_mbus_win_offset,

	.save_cpu_target     = mvebu_mbus_default_save_cpu_target,

	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,

	.show_cpu_target     = mvebu_sdram_debug_show_orion,

};
@@ -620,6 +673,7 @@ static const struct mvebu_mbus_soc_data mv78xx0_mbus_data = { 
	.num_wins            = 14,

	.num_remappable_wins = 8,

	.win_cfg_offset      = mv78xx0_mbus_win_offset,

	.save_cpu_target     = mvebu_mbus_default_save_cpu_target,

	.setup_cpu_target    = mvebu_mbus_default_setup_cpu_target,

	.show_cpu_target     = mvebu_sdram_debug_show_orion,

};
@@ -804,6 +858,8 @@ static int __init mvebu_mbus_common_init(struct mvebu_mbus_state *mbus, 
		return -ENOMEM;

	}



	mbus->sdramwins_phys_base = sdramwins_phys_base;



	if (mbusbridge_phys_base) {

		mbus->mbusbridge_base = ioremap(mbusbridge_phys_base,

						mbusbridge_size);

include/linux/mbus.h

+1 −0
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ static inline const struct mbus_dram_target_info *mv_mbus_dram_info(void) 
}

#endif



int mvebu_mbus_save_cpu_target(u32 *store_addr);

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_by_id(unsigned int target,