ARM: pxa: transition to dmaengine phase 1

In order to slowly transition pxa to dmaengine, the legacy code will now
rely on dmaengine to request a channel.

This implies that PXA architecture selects DMADEVICES and PXA_DMA,
which is not pretty. Yet it enables PXA drivers to be ported one by one,
with part of them using dmaengine, and the other part using the legacy
code.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>

diff --git a/arch/arm/mach-pxa/devices.c b/arch/arm/mach-pxa/devices.c
index 35434662dc7c2ff3e6231b13884f4ea709eae278..e6ce669b54af49af62b74940e19f98d549fd5947 100644 (file)
--- a/arch/arm/mach-pxa/devices.c
+++ b/arch/arm/mach-pxa/devices.c
@@ -17,6 +17,7 @@
 #include <linux/platform_data/camera-pxa.h>
 #include <mach/audio.h>
 #include <mach/hardware.h>
+#include <linux/platform_data/mmp_dma.h>
 #include <linux/platform_data/mtd-nand-pxa3xx.h>
 
 #include "devices.h"
@@ -1193,3 +1194,39 @@ void __init pxa2xx_set_spi_info(unsigned id, struct pxa2xx_spi_master *info)
        pd->dev.platform_data = info;
        platform_device_add(pd);
 }
+
+static struct mmp_dma_platdata pxa_dma_pdata = {
+       .dma_channels   = 0,
+};
+
+static struct resource pxa_dma_resource[] = {
+       [0] = {
+               .start  = 0x40000000,
+               .end    = 0x4000ffff,
+               .flags  = IORESOURCE_MEM,
+       },
+       [1] = {
+               .start  = IRQ_DMA,
+               .end    = IRQ_DMA,
+               .flags  = IORESOURCE_IRQ,
+       },
+};
+
+static u64 pxadma_dmamask = 0xffffffffUL;
+
+static struct platform_device pxa2xx_pxa_dma = {
+       .name           = "pxa-dma",
+       .id             = 0,
+       .dev            = {
+               .dma_mask = &pxadma_dmamask,
+               .coherent_dma_mask = 0xffffffff,
+       },
+       .num_resources  = ARRAY_SIZE(pxa_dma_resource),
+       .resource       = pxa_dma_resource,
+};
+
+void __init pxa2xx_set_dmac_info(int nb_channels)
+{
+       pxa_dma_pdata.dma_channels = nb_channels;
+       pxa_register_device(&pxa2xx_pxa_dma, &pxa_dma_pdata);
+}

diff --git a/arch/arm/mach-pxa/pxa25x.c b/arch/arm/mach-pxa/pxa25x.c
index 23a90c62ec11bf3b82ed77693351a669a6dc697a..1dc85ffc3e20a470ca1a099c8eadbb1c026ec932 100644 (file)
--- a/arch/arm/mach-pxa/pxa25x.c
+++ b/arch/arm/mach-pxa/pxa25x.c
@@ -206,6 +206,7 @@ static int __init pxa25x_init(void)
                register_syscore_ops(&pxa_irq_syscore_ops);
                register_syscore_ops(&pxa2xx_mfp_syscore_ops);
 
+               pxa2xx_set_dmac_info(16);
                pxa_register_device(&pxa25x_device_gpio, &pxa25x_gpio_info);
                ret = platform_add_devices(pxa25x_devices,
                                           ARRAY_SIZE(pxa25x_devices));

diff --git a/arch/arm/mach-pxa/pxa27x.c b/arch/arm/mach-pxa/pxa27x.c
index b5abdeb5bb2d17d6e63e4bc844047e0ea1928b05..e6aae9e8adfbdc334876308306c6bf9e1dedd2cf 100644 (file)
--- a/arch/arm/mach-pxa/pxa27x.c
+++ b/arch/arm/mach-pxa/pxa27x.c
@@ -310,6 +310,7 @@ static int __init pxa27x_init(void)
                if (!of_have_populated_dt()) {
                        pxa_register_device(&pxa27x_device_gpio,
                                            &pxa27x_gpio_info);
+                       pxa2xx_set_dmac_info(32);
                        ret = platform_add_devices(devices,
                                                   ARRAY_SIZE(devices));
                }

diff --git a/arch/arm/mach-pxa/pxa3xx.c b/arch/arm/mach-pxa/pxa3xx.c
index bd4cbef15ccf2147a7cce6aa1d51f185cfd57f8f..aa85ec1a3065a413f3da32d02c89954891c8fe38 100644 (file)
--- a/arch/arm/mach-pxa/pxa3xx.c
+++ b/arch/arm/mach-pxa/pxa3xx.c
@@ -431,6 +431,7 @@ static int __init pxa3xx_init(void)
                if (of_have_populated_dt())
                        return 0;
 
+               pxa2xx_set_dmac_info(32);
                ret = platform_add_devices(devices, ARRAY_SIZE(devices));
                if (ret)
                        return ret;

diff --git a/arch/arm/plat-pxa/dma.c b/arch/arm/plat-pxa/dma.c
index d92f07f6ecfb3b2d171f41b286285c2fd1f49d48..de2b061889ec24eb855124c856c89b1a876948e9 100644 (file)
--- a/arch/arm/plat-pxa/dma.c
+++ b/arch/arm/plat-pxa/dma.c
@@ -289,7 +289,8 @@ int pxa_request_dma (char *name, pxa_dma_prio prio,
                /* try grabbing a DMA channel with the requested priority */
                for (i = 0; i < num_dma_channels; i++) {
                        if ((dma_channels[i].prio == prio) &&
-                           !dma_channels[i].name) {
+                           !dma_channels[i].name &&
+                           !pxad_toggle_reserved_channel(i)) {
                                found = 1;
                                break;
                        }
@@ -326,13 +327,14 @@ void pxa_free_dma (int dma_ch)
        local_irq_save(flags);
        DCSR(dma_ch) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
        dma_channels[dma_ch].name = NULL;
+       pxad_toggle_reserved_channel(dma_ch);
        local_irq_restore(flags);
 }
 EXPORT_SYMBOL(pxa_free_dma);
 
 static irqreturn_t dma_irq_handler(int irq, void *dev_id)
 {
-       int i, dint = DINT;
+       int i, dint = DINT, done = 0;
        struct dma_channel *channel;
 
        while (dint) {
@@ -341,16 +343,13 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id)
                channel = &dma_channels[i];
                if (channel->name && channel->irq_handler) {
                        channel->irq_handler(i, channel->data);
-               } else {
-                       /*
-                        * IRQ for an unregistered DMA channel:
-                        * let's clear the interrupts and disable it.
-                        */
-                       printk (KERN_WARNING "spurious IRQ for DMA channel %d\n", i);
-                       DCSR(i) = DCSR_STARTINTR|DCSR_ENDINTR|DCSR_BUSERR;
+                       done++;
                }
        }
-       return IRQ_HANDLED;
+       if (done)
+               return IRQ_HANDLED;
+       else
+               return IRQ_NONE;
 }
 
 int __init pxa_init_dma(int irq, int num_ch)
@@ -372,7 +371,8 @@ int __init pxa_init_dma(int irq, int num_ch)
                spin_lock_init(&dma_channels[i].lock);
        }
 
-       ret = request_irq(irq, dma_irq_handler, 0, "DMA", NULL);
+       ret = request_irq(irq, dma_irq_handler, IRQF_SHARED, "DMA",
+                         dma_channels);
        if (ret) {
                printk (KERN_CRIT "Wow!  Can't register IRQ for DMA\n");
                kfree(dma_channels);

diff --git a/arch/arm/plat-pxa/include/plat/dma.h b/arch/arm/plat-pxa/include/plat/dma.h
index a7b91dc06852bc0c139077dee579c3b27f2b1dbb..28848b344e2d945e0d7b7d6bbc128d231b957b6a 100644 (file)
--- a/arch/arm/plat-pxa/include/plat/dma.h
+++ b/arch/arm/plat-pxa/include/plat/dma.h
@@ -82,4 +82,19 @@ int pxa_request_dma (char *name,
 
 void pxa_free_dma (int dma_ch);
 
+/*
+ * Cooperation with pxa_dma + dmaengine while there remains at least one pxa
+ * driver not converted to dmaengine.
+ */
+#if defined(CONFIG_PXA_DMA)
+extern int pxad_toggle_reserved_channel(int legacy_channel);
+#else
+static inline int pxad_toggle_reserved_channel(int legacy_channel)
+{
+       return 0;
+}
+#endif
+
+extern void __init pxa2xx_set_dmac_info(int nb_channels);
+
 #endif /* __PLAT_DMA_H */