[PATCH v2 5/7] ARM: of: introduce common routine for DMA configuration
From: Santosh Shilimkar <hidden>
Date: 2014-02-27 21:17:50
Also in:
linux-devicetree
Subsystem:
arm port, open firmware and flattened device tree, the rest · Maintainers:
Russell King, Rob Herring, Saravana Kannan, Linus Torvalds
Possibly related (same subject, not in this thread)
- 2014-02-28 · Re: [PATCH v2 5/7] ARM: of: introduce common routine for DMA configuration · Santosh Shilimkar <hidden>
- 2014-02-28 · Re: [PATCH v2 5/7] ARM: of: introduce common routine for DMA configuration · Arnd Bergmann <hidden>
- 2014-02-28 · Re: [PATCH v2 5/7] ARM: of: introduce common routine for DMA configuration · Rob Herring <hidden>
From: Grygorii Strashko <grygorii.strashko@ti.com>
This patch introduces ARM specific function arm_dt_dma_configure()
which intended to retrieve DMA configuration from DT and setup Platform
device's DMA parameters.
The DMA configuration in DT has to be specified using "dma-ranges"
and "dam-coherent" properties if supported. The DMA configuration applied
by arm_dt_dma_configure() as following:
- call of_get_dma_range() and get supported DMA range info
(dma_addr, cpu_addr, dma_size);
- if "not found" then fill dma_mask as DMA_BIT_MASK(32)
(this is default behaviour);
- if "failed" then clean up dma_mask (DMA not supported)
- if ok then update devices DMA configuration:
set dma_mask to (dma_addr + dma_size - 1)
set dma_pfn_offset to PFN_DOWN(cpu_addr - dma_addr)
Cc: Russell King <redacted>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <redacted>
Cc: Grant Likely <redacted>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <redacted>
---
arch/arm/include/asm/prom.h | 3 +++
arch/arm/kernel/devtree.c | 61 +++++++++++++++++++++++++++++++++++++++++++
drivers/of/platform.c | 5 +++-
include/linux/of.h | 2 +-
4 files changed, 69 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/prom.h b/arch/arm/include/asm/prom.h
index b681575..1acb732 100644
--- a/arch/arm/include/asm/prom.h
+++ b/arch/arm/include/asm/prom.h@@ -11,11 +11,13 @@ #ifndef __ASMARM_PROM_H #define __ASMARM_PROM_H +struct device; #ifdef CONFIG_OF extern const struct machine_desc *setup_machine_fdt(unsigned int dt_phys); extern void arm_dt_memblock_reserve(void); extern void __init arm_dt_init_cpu_maps(void); +extern void arm_dt_dma_configure(struct device *dev); #else /* CONFIG_OF */
@@ -26,6 +28,7 @@ static inline const struct machine_desc *setup_machine_fdt(unsigned int dt_phys) static inline void arm_dt_memblock_reserve(void) { } static inline void arm_dt_init_cpu_maps(void) { } +static inline void arm_dt_dma_configure(struct device *dev) { } #endif /* CONFIG_OF */ #endif /* ASMARM_PROM_H */
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index f751714..926b5dd 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c@@ -18,6 +18,9 @@ #include <linux/of_fdt.h> #include <linux/of_irq.h> #include <linux/of_platform.h> +#include <linux/of_dma.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> #include <asm/cputype.h> #include <asm/setup.h>
@@ -235,3 +238,61 @@ const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys) return mdesc; } + +void arm_dt_dma_configure(struct device *dev) +{ + dma_addr_t dma_addr; + phys_addr_t paddr, size; + dma_addr_t dma_mask; + int ret; + + /* + * if dma-ranges property doesn't exist - use 32 bits DMA mask + * by default and don't set skip archdata.dma_pfn_offset + */ + ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size); + if (ret == -ENODEV) { + dev->coherent_dma_mask = DMA_BIT_MASK(32); + if (!dev->dma_mask) + dev->dma_mask = &dev->coherent_dma_mask; + return; + } + + /* if failed - disable DMA for device */ + if (ret < 0) { + dev_err(dev, "failed to configure DMA\n"); + return; + } + + /* DMA ranges found. Calculate and set dma_pfn_offset */ + dev->archdata.dma_pfn_offset = PFN_DOWN(paddr - dma_addr); + + /* Configure DMA mask */ + dev->dma_mask = kmalloc(sizeof(*dev->dma_mask), GFP_KERNEL); + if (!dev->dma_mask) + return; + + dma_mask = dma_addr + size - 1; + + ret = arm_dma_set_mask(dev, dma_mask); + if (ret < 0) { + dev_err(dev, "failed to set DMA mask %#08x\n", dma_mask); + kfree(dev->dma_mask); + dev->dma_mask = NULL; + return; + } + + dev_dbg(dev, "dma_pfn_offset(%#08lx) dma_mask(%#016llx)\n", + dev->archdata.dma_pfn_offset, *dev->dma_mask); + + if (of_dma_is_coherent(dev->of_node)) { + set_dma_ops(dev, &arm_coherent_dma_ops); + dev_dbg(dev, "device is dma coherent\n"); + } + + ret = dma_set_coherent_mask(dev, dma_mask); + if (ret < 0) { + dev_err(dev, "failed to set coherent DMA mask %#08x\n", + dma_mask); + } +}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 404d1da..97d5533 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c@@ -213,10 +213,13 @@ static struct platform_device *of_platform_device_create_pdata( #if defined(CONFIG_MICROBLAZE) dev->archdata.dma_mask = 0xffffffffUL; -#endif +#elif defined(CONFIG_ARM_LPAE) + arm_dt_dma_configure(&dev->dev); +#else dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); if (!dev->dev.dma_mask) dev->dev.dma_mask = &dev->dev.coherent_dma_mask; +#endif dev->dev.bus = &platform_bus_type; dev->dev.platform_data = platform_data;
diff --git a/include/linux/of.h b/include/linux/of.h
index 70c64ba..a321058 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h@@ -136,7 +136,7 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size) return of_read_number(cell, size); } -#if defined(CONFIG_SPARC) +#if defined(CONFIG_SPARC) || defined(CONFIG_ARM_LPAE) #include <asm/prom.h> #endif
--
1.7.9.5