[PATCH 8/9] arm: twr-k70f120m: extend Freescale eDMA driver with ability to support Kinetis SoC

Paul Osmialowski
2015-06-23T21:51:39Z

Surprisingly small amount of work was required in order to extend already
existing eDMA driver with the support for Kinetis SoC architecture.

Note that <mach/memory.h> is needed (which is denoted by
CONFIG_NEED_MACH_MEMORY_H) as it provides macros required for proper
operation of DMA allocation functions.

Signed-off-by: Paul Osmialowski <pawelo@king.net.pl>
---
Documentation/devicetree/bindings/dma/fsl-edma.txt | 38 +++++++++-
arch/arm/Kconfig | 4 ++
arch/arm/boot/dts/kinetis.dtsi | 34 +++++++++
arch/arm/mach-kinetis/include/mach/memory.h | 61 ++++++++++++++++
drivers/clk/clk-kinetis.c | 15 ++++
drivers/dma/fsl-edma.c | 81 +++++++++++++++++++++-
include/dt-bindings/clock/kinetis-mcg.h | 5 +-
7 files changed, 235 insertions(+), 3 deletions(-)
create mode 100644 arch/arm/mach-kinetis/include/mach/memory.h

diff --git a/Documentation/devicetree/bindings/dma/fsl-edma.txt b/Documentation/devicetree/bindings/dma/fsl-edma.txt
index 191d7bd..e1ee406 100644
--- a/Documentation/devicetree/bindings/dma/fsl-edma.txt
+++ b/Documentation/devicetree/bindings/dma/fsl-edma.txt
@@ -9,6 +9,7 @@ group, DMAMUX0 or DMAMUX1, but not both.
Required properties:
- compatible :
- "fsl,vf610-edma" for eDMA used similar to that on Vybrid vf610 SoC
+ - "fsl,kinetis-edma" for eDMA used similar to that on Kinetis SoC
- reg : Specifies base physical address(s) and size of the eDMA registers.
The 1st region is eDMA control register's address and size.
The 2nd and the 3rd regions are programmable channel multiplexing
@@ -16,7 +17,8 @@ Required properties:
- interrupts : A list of interrupt-specifiers, one for each entry in
interrupt-names.
- interrupt-names : Should contain:
- "edma-tx" - the transmission interrupt
+ "edma-tx" - the transmission interrupt (Vybrid)
+ "edma-tx-n,m" - interrupt for channels n (0-15) and m (16-31) (Kinetis)
"edma-err" - the error interrupt
- #dma-cells : Must be <2>.
The 1st cell specifies the DMAMUX(0 for DMAMUX0 and 1 for DMAMUX1).
@@ -28,6 +30,7 @@ Required properties:
- clock-names : A list of channel group clock names. Should contain:
"dmamux0" - clock name of mux0 group
"dmamux1" - clock name of mux1 group
+ "edma" - clock gate for whole controller (Kinetis only)
- clocks : A list of phandle and clock-specifier pairs, one for each entry in
clock-names.

@@ -54,6 +57,39 @@ edma0: dma-controller@40018000 {
<&clks VF610_CLK_DMAMUX1>;
};

+edma: dma-controller@40008000 {
+ compatible = "fsl,kinetis-edma";
+ reg = <0x40008000 0x2000>, /* DMAC */
+ <0x40021000 0x1000>, /* DMAMUX0 */
+ <0x40022000 0x1000>; /* DMAMUX1 */
+ #dma-cells = <2>;
+ dma-channels = <32>;
+ interrupts = <0>, <1>, <2>, <3>,
+ <4>, <5>, <6>, <7>,
+ <8>, <9>, <10>, <11>,
+ <12>, <13>, <14>, <15>,
+ <16>;
+ interrupt-names = "edma-tx-0,16",
+ "edma-tx-1,17",
+ "edma-tx-2,18",
+ "edma-tx-3,19",
+ "edma-tx-4,20",
+ "edma-tx-5,21",
+ "edma-tx-6,22",
+ "edma-tx-7,23",
+ "edma-tx-8,24",
+ "edma-tx-9,25",
+ "edma-tx-10,26",
+ "edma-tx-11,27",
+ "edma-tx-12,28",
+ "edma-tx-13,29",
+ "edma-tx-14,30",
+ "edma-tx-15,31",
+ "edma-err";
+ clocks = <&mcg CLOCK_EDMA>,
+ <&mcg CLOCK_DMAMUX0>, <&mcg CLOCK_DMAMUX1>;
+ clock-names = "edma", "dmamux0", "dmamux1";
+};

* DMA clients
DMA client drivers that uses the DMA function must use the format described
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 662447c..154436a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -981,6 +981,10 @@ config ARCH_KINETIS
select ARMV7M_SYSTICK
select CLKSRC_KINETIS
select PINCTRL
+ select DMADEVICES
+ select FSL_EDMA
+ select DMA_OF
+ select NEED_MACH_MEMORY_H
select ZLIB_INFLATE_STACK_SAVING if ZLIB_INFLATE
help
This enables support for the Freescale Kinetis MCUs
diff --git a/arch/arm/boot/dts/kinetis.dtsi b/arch/arm/boot/dts/kinetis.dtsi
index f3f22b5..7638103 100644
--- a/arch/arm/boot/dts/kinetis.dtsi
+++ b/arch/arm/boot/dts/kinetis.dtsi
@@ -20,6 +20,40 @@
};

soc {
+ edma: dma-controller@40008000 {
+ compatible = "fsl,kinetis-edma";
+ reg = <0x40008000 0x2000>, /* DMAC */
+ <0x40021000 0x1000>, /* DMAMUX0 */
+ <0x40022000 0x1000>; /* DMAMUX1 */
+ #dma-cells = <2>;
+ dma-channels = <32>;
+ interrupts = <0>, <1>, <2>, <3>,
+ <4>, <5>, <6>, <7>,
+ <8>, <9>, <10>, <11>,
+ <12>, <13>, <14>, <15>,
+ <16>;
+ interrupt-names = "edma-tx-0,16",
+ "edma-tx-1,17",
+ "edma-tx-2,18",
+ "edma-tx-3,19",
+ "edma-tx-4,20",
+ "edma-tx-5,21",
+ "edma-tx-6,22",
+ "edma-tx-7,23",
+ "edma-tx-8,24",
+ "edma-tx-9,25",
+ "edma-tx-10,26",
+ "edma-tx-11,27",
+ "edma-tx-12,28",
+ "edma-tx-13,29",
+ "edma-tx-14,30",
+ "edma-tx-15,31",
+ "edma-err";
+ clocks = <&mcg CLOCK_EDMA>,
+ <&mcg CLOCK_DMAMUX0>, <&mcg CLOCK_DMAMUX1>;
+ clock-names = "edma", "dmamux0", "dmamux1";
+ };
+
portA: pinmux@40049000 {
compatible = "fsl,kinetis-padconf";
reg = <0x40049000 0x1000>;
diff --git a/arch/arm/mach-kinetis/include/mach/memory.h b/arch/arm/mach-kinetis/include/mach/memory.h
new file mode 100644
index 0000000..8bad034
--- /dev/null
+++ b/arch/arm/mach-kinetis/include/mach/memory.h
@@ -0,0 +1,61 @@
+/*
+ * Based on original code by Alexander Potashev <aspotashev@emcraft.com>
+ *
+ * (C) Copyright 2011, 2012
+ * Emcraft Systems, <www.emcraft.com>
+ * Alexander Potashev <aspotashev@emcraft.com>
+ *
+ * Copyright (C) 2015 Paul Osmialowski <pawelo@king.net.pl>
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ */
+
+#ifndef _MACH_KINETIS_MEMORY_H
+#define _MACH_KINETIS_MEMORY_H
+
+#ifndef __ASSEMBLY__
+
+/*
+ * On Kinetis K70, consistent DMA memory resides in a special
+ * DDRAM alias region (non-cacheable DDRAM at 0x80000000).
+ *
+ */
+#define KINETIS_PHYS_DMA_OFFSET UL(0x80000000)
+
+/*
+ * Mask of the field used to distinguish DDRAM aliases
+ */
+#define KINETIS_DRAM_ALIAS_MASK UL(0xf8000000)
+
+/*
+ * This macro converts an address in the kernel run-time memory
+ * to an alias in the non-cacheable memory region
+ */
+#define KINETIS_DMA_ALIAS_ADDR(addr) \
+ (((unsigned long)(addr) & ~KINETIS_DRAM_ALIAS_MASK) | \
+ (KINETIS_PHYS_DMA_OFFSET & KINETIS_DRAM_ALIAS_MASK))
+
+/*
+ * This macro converts an address in the kernel code or
+ * in the non-cacheable DMA region to an alias in
+ * the run-time kernel memory region
+ */
+#define KINETIS_PHYS_ALIAS_ADDR(addr) \
+ ((unsigned long)(addr) & ~KINETIS_DRAM_ALIAS_MASK)
+
+#define __arch_dma_to_pfn(dev, addr) __phys_to_pfn(addr)
+
+#define __arch_pfn_to_dma(dev, pfn) \
+ ((dma_addr_t)KINETIS_DMA_ALIAS_ADDR(__pfn_to_phys(pfn)))
+
+#define __arch_dma_to_virt(dev, addr) \
+ ((void *)KINETIS_PHYS_ALIAS_ADDR(addr))
+
+#define __arch_virt_to_dma(dev, addr) \
+ ((dma_addr_t)KINETIS_DMA_ALIAS_ADDR(addr))
+
+#endif /* __ASSEMBLY__ */
+
+#endif /*_MACH_KINETIS_MEMORY_H */
diff --git a/drivers/clk/clk-kinetis.c b/drivers/clk/clk-kinetis.c
index b6620c0..454096c 100644
--- a/drivers/clk/clk-kinetis.c
+++ b/drivers/clk/clk-kinetis.c
@@ -248,6 +248,21 @@ static void __init kinetis_mcg_init(struct device_node *np)
KINETIS_SIM_PTR(scgc[KINETIS_CG_REG(KINETIS_CG_PORTF)]),
KINETIS_CG_IDX(KINETIS_CG_PORTF), 0, NULL);

+ /*
+ * DMA clock gates, see K70 Sub-Family Reference Manual, Rev. 3 pg. 223:
+ */
+ clk[CLOCK_EDMA] = clk_register_gate(NULL, "EDMA", "CCLK", 0,
+ KINETIS_SIM_PTR(scgc[KINETIS_CG_REG(KINETIS_CG_DMA)]),
+ KINETIS_CG_IDX(KINETIS_CG_DMA), 0, NULL);
+
+ clk[CLOCK_DMAMUX0] = clk_register_gate(NULL, "DMAMUX0", "PCLK", 0,
+ KINETIS_SIM_PTR(scgc[KINETIS_CG_REG(KINETIS_CG_DMAMUX0)]),
+ KINETIS_CG_IDX(KINETIS_CG_DMAMUX0), 0, NULL);
+
+ clk[CLOCK_DMAMUX1] = clk_register_gate(NULL, "DMAMUX1", "PCLK", 0,
+ KINETIS_SIM_PTR(scgc[KINETIS_CG_REG(KINETIS_CG_DMAMUX1)]),
+ KINETIS_CG_IDX(KINETIS_CG_DMAMUX1), 0, NULL);
+
of_clk_add_provider(np, of_clk_src_onecell_get, &clk_data);
}

diff --git a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c
index 915eec3..655d819 100644
--- a/drivers/dma/fsl-edma.c
+++ b/drivers/dma/fsl-edma.c
@@ -161,14 +161,42 @@ struct fsl_edma_desc {
struct fsl_edma_sw_tcd tcd[];
};

+#ifdef CONFIG_ARCH_KINETIS
+static const char * const txirq_names[] = {
+ "edma-tx-0,16",
+ "edma-tx-1,17",
+ "edma-tx-2,18",
+ "edma-tx-3,19",
+ "edma-tx-4,20",
+ "edma-tx-5,21",
+ "edma-tx-6,22",
+ "edma-tx-7,23",
+ "edma-tx-8,24",
+ "edma-tx-9,25",
+ "edma-tx-10,26",
+ "edma-tx-11,27",
+ "edma-tx-12,28",
+ "edma-tx-13,29",
+ "edma-tx-14,30",
+ "edma-tx-15,31",
+};
+#endif
+
struct fsl_edma_engine {
struct dma_device dma_dev;
void __iomem *membase;
+#ifdef CONFIG_ARCH_KINETIS
+ struct clk *clk;
+#endif
void __iomem *muxbase[DMAMUX_NR];
struct clk *muxclk[DMAMUX_NR];
struct mutex fsl_edma_mutex;
u32 n_chans;
+#ifdef CONFIG_ARCH_KINETIS
+ int txirq[ARRAY_SIZE(txirq_names)];
+#else
int txirq;
+#endif
int errirq;
bool big_endian;
struct fsl_edma_chan chans[];
@@ -709,6 +737,7 @@ static irqreturn_t fsl_edma_err_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}

+#ifndef CONFIG_ARCH_KINETIS
static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)
{
if (fsl_edma_tx_handler(irq, dev_id) == IRQ_HANDLED)
@@ -716,6 +745,7 @@ static irqreturn_t fsl_edma_irq_handler(int irq, void *dev_id)

return fsl_edma_err_handler(irq, dev_id);
}
+#endif

static void fsl_edma_issue_pending(struct dma_chan *chan)
{
@@ -788,15 +818,29 @@ static void fsl_edma_free_chan_resources(struct dma_chan *chan)
}

static int
-fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma)
+fsl_edma_irq_init(struct platform_device *pdev,
+ struct fsl_edma_engine *fsl_edma)
{
int ret;
+#ifdef CONFIG_ARCH_KINETIS
+ int i;

+ for (i = 0; i < ARRAY_SIZE(txirq_names); i++) {
+ fsl_edma->txirq[i] = platform_get_irq_byname(pdev,
+ txirq_names[i]);
+ if (fsl_edma->txirq[i] < 0) {
+ dev_err(&pdev->dev, "Can't get %s irq.\n",
+ txirq_names[i]);
+ return fsl_edma->txirq[i];
+ }
+ }
+#else
fsl_edma->txirq = platform_get_irq_byname(pdev, "edma-tx");
if (fsl_edma->txirq < 0) {
dev_err(&pdev->dev, "Can't get edma-tx irq.\n");
return fsl_edma->txirq;
}
+#endif

fsl_edma->errirq = platform_get_irq_byname(pdev, "edma-err");
if (fsl_edma->errirq < 0) {
@@ -804,6 +848,16 @@ fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma
return fsl_edma->errirq;
}

+#ifdef CONFIG_ARCH_KINETIS
+ for (i = 0; i < ARRAY_SIZE(txirq_names); i++) {
+ ret = devm_request_irq(&pdev->dev, fsl_edma->txirq[i],
+ fsl_edma_tx_handler, 0, txirq_names[i], fsl_edma);
+ if (ret) {
+ dev_err(&pdev->dev, "Can't register eDMA tx IRQ.\n");
+ return ret;
+ }
+ }
+#else
if (fsl_edma->txirq == fsl_edma->errirq) {
ret = devm_request_irq(&pdev->dev, fsl_edma->txirq,
fsl_edma_irq_handler, 0, "eDMA", fsl_edma);
@@ -818,6 +872,7 @@ fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma
dev_err(&pdev->dev, "Can't register eDMA tx IRQ.\n");
return ret;
}
+#endif

ret = devm_request_irq(&pdev->dev, fsl_edma->errirq,
fsl_edma_err_handler, 0, "eDMA err", fsl_edma);
@@ -825,7 +880,9 @@ fsl_edma_irq_init(struct platform_device *pdev, struct fsl_edma_engine *fsl_edma
dev_err(&pdev->dev, "Can't register eDMA err IRQ.\n");
return ret;
}
+#ifndef CONFIG_ARCH_KINETIS
}
+#endif

return 0;
}
@@ -858,6 +915,20 @@ static int fsl_edma_probe(struct platform_device *pdev)
if (IS_ERR(fsl_edma->membase))
return PTR_ERR(fsl_edma->membase);

+#ifdef CONFIG_ARCH_KINETIS
+ fsl_edma->clk = devm_clk_get(&pdev->dev, "edma");
+ if (IS_ERR(fsl_edma->clk)) {
+ dev_err(&pdev->dev, "Missing EDMA clock.\n");
+ return PTR_ERR(fsl_edma->clk);
+ }
+
+ ret = clk_prepare_enable(fsl_edma->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "EDMA clk failed.\n");
+ return ret;
+ }
+#endif
+
for (i = 0; i < DMAMUX_NR; i++) {
char clkname[32];

@@ -956,11 +1027,19 @@ static int fsl_edma_remove(struct platform_device *pdev)
for (i = 0; i < DMAMUX_NR; i++)
clk_disable_unprepare(fsl_edma->muxclk[i]);

+#ifdef CONFIG_ARCH_KINETIS
+ clk_disable_unprepare(fsl_edma->clk);
+#endif
+
return 0;
}

static const struct of_device_id fsl_edma_dt_ids[] = {
+#ifdef CONFIG_ARCH_KINETIS
+ { .compatible = "fsl,kinetis-edma", },
+#else
{ .compatible = "fsl,vf610-edma", },
+#endif
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, fsl_edma_dt_ids);
diff --git a/include/dt-bindings/clock/kinetis-mcg.h b/include/dt-bindings/clock/kinetis-mcg.h
index 5eaeeec..d853c3c 100644
--- a/include/dt-bindings/clock/kinetis-mcg.h
+++ b/include/dt-bindings/clock/kinetis-mcg.h
@@ -11,6 +11,9 @@
#define CLOCK_PORTD 7
#define CLOCK_PORTE 8
#define CLOCK_PORTF 9
-#define CLOCK_END 10
+#define CLOCK_EDMA 10
+#define CLOCK_DMAMUX0 11
+#define CLOCK_DMAMUX1 12
+#define CLOCK_END 13

#endif /* _DT_BINDINGS_CLOCK_KINETIS_MCG_H */
--
2.3.6