[PATCH V2] ARM: NUC900: add GDMA driver support for nuc900 platform
Wan ZongShun
mcuos.com at gmail.com
Wed Dec 9 09:50:08 EST 2009
Hi Hu,
Thanks a lot for your patch, a comment below.
2009/12/8 Hu Ruihuan <specter118 at gmail.com>:
> Hi Wan,
> I am sorry to make such a stupid mistake. The correct patch below.
>
> Signed-off-by: Hu Ruihuan <specter118 at gmail.com>
> ---
> diff -uNr b/linux-2.6.32-rc8/arch/arm/mach-w90x900/dma.c
> a/arch/arm/mach-w90x900/dma.c
> --- b/linux-2.6.32-rc8/arch/arm/mach-w90x900/dma.c 1970-01-01
> 08:00:00.000000000 +0800
> +++ a/arch/arm/mach-w90x900/dma.c 2009-12-08 23:34:39.000000000 +0800
> @@ -0,0 +1,295 @@
> +/*
> + * arch/arm/mach-w90p910/dma.c
> + *
> + * Support functions for the w90p910 internal DMA channels.
> + *
> + * Wan Zongshun <mcuos.com at gmail.com>
> + * Hu Ruihuan <specter118 at gmail.com>
> + *
> + * 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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/interrupt.h>
> +#include <linux/init.h>
> +#include <linux/spinlock.h>
> +#include <linux/errno.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <asm/system.h>
> +#include <asm/irq.h>
> +#include <asm/atomic.h>
> +#include <mach/hardware.h>
> +
> +#define NUC900_DMA_CHANNELS (2)
> +#define DMA_BASE (W90X900_VA_GDMA)
> +#define GDMA_INTCS (DMA_BASE + 0xa0)
> +#define GDMA_GDGA (0x1c)
> +#define TC0F (0x01 << 8)
> +#define TC1F (0x01 << 10)
> +#define ENTC0F (0x01)
> +#define ENTC1F (0x01 << 2)
> +
> +#define GDMAEN (0x01)
> +#define GDMAMS (0x03 << 2)
> +#define DADIR (0x01 << 4)
> +#define SADIR (0x01 << 5)
> +#define DAFIX (0x01 << 6)
> +#define SAFIX (0x01 << 7)
> +#define D_INTS (0x01 << 10)
> +#define TWSMASK (0x03 << 12)
> +#define TWS (0x02 << 12)
> +
> +#define RUN (0x01 << 3)
> +#define NON_DSCRIP (0x01 << 2)
> +#define ORDEN (0x01 << 1)
> +#define RESET (0x01)
> +#define DSCRIPMASK (0x0F)
> +#define CMDINFOMASK (0x03FFF)
> +
> +#define COUTN_TRANSFER (0x1000)/*count[13:0]=1024*/
> +#define CHANNELINERV (0x20)
> +
> +typedef void (*dma_callback_t)(void *data);
> +
> +struct nuc900_dma_descp {
> + unsigned int next_descp;
> + unsigned int srcaddr;
> + unsigned int dstaddr;
> + unsigned int commandinfo;
> +};
> +
> +struct nuc900_dma {
> + const char *device; /* this channel device, 0 if unused */
> + dma_callback_t callback; /* to call when DMA completes */
> + void __iomem *dma_reg;
> + void *data; /* ... with private data ptr */
> + struct nuc900_dma_descp *descp;
> +};
> +
> +static struct nuc900_dma dma_chan[NUC900_DMA_CHANNELS];
> +static struct nuc900_dma *dmachan0, *dmachan1;
> +static atomic_t shared_irq_using;
> +static DEFINE_SPINLOCK(dma_chan_lock);
> +static struct nuc900_dma *register_dmachan_fromname(const char *dev_name,
> + unsigned int *irq_request)
> +{
> + struct nuc900_dma *ret = NULL;
> +
> + BUG_ON(!dev_name);
> +
> +
> + if (!(dmachan0->device) && !(dmachan1->device)) {
> + ret = dmachan0;
> + *irq_request = 1;
> + } else if ((dmachan0->device) && !(dmachan1->device)) {
> + if (strcmp(dmachan0->device, dev_name) == 0)
> + ret = ERR_PTR(-EBUSY);
> + else
> + ret = dmachan1;
> + } else if ((dmachan1->device) && !(dmachan0->device)) {
> + if (strcmp(dmachan1->device, dev_name) == 0)
> + ret = ERR_PTR(-EBUSY);
> + else
> + ret = dmachan0;
> + } else
> + ret = ERR_PTR(-EBUSY);
> +
> + return ret;
> +
> +}
> +
> +static void match_dmachan_fromname(const char *dev_name,
> + struct nuc900_dma **dma)
> +{
> + BUG_ON(!dev_name);
> +
> + if (dmachan1->device) {
> + if (strcmp(dmachan1->device, dev_name) == 0)
> + *dma = dmachan1;
> + } else if (dmachan0->device) {
> + if (strcmp(dmachan0->device, dev_name) == 0)
> + *dma = dmachan0;
> + }
> +}
> +
> +static irqreturn_t dma_irq_handler(int irq, void *dev_id)
> +{
> + int status;
> + local_irq_disable();
> + status = __raw_readl(GDMA_GDGA) & (TC0F|TC1F);
> + __raw_writel(~status, GDMA_GDGA);
> + local_irq_enable();
> +
> + if (status & TC0F)
> + dmachan0->callback(dmachan0->data);
> + if (status & TC1F)
> + dmachan1->callback(dmachan1->data);
> +
> + return IRQ_HANDLED;
> +}
> +
> +int nuc900_request_dma(const char *dev_name, dma_callback_t callback,
> + void *data)
> +{
> + struct nuc900_dma *dma = NULL;
> + int err, irq_request;
> + err = 0;
> + irq_request = 0;
> + spin_lock(&dma_chan_lock);
> + dma = register_dmachan_fromname(dev_name, &irq_request);
> +
> + if (IS_ERR(dma)) {
> + err = ERR_PTR(dma);
hi, I think it should be PTR_ERR rather than ERR_PTR, such as:
err = PTR_ERR(dma);
> + spin_unlock(&dma_chan_lock);
> + return err;
> + }
> + dma->device = dev_name;
> + atomic_inc(&shared_irq_using);
> + dma->callback = callback;
> + dma->data = data;
> + spin_unlock(&dma_chan_lock);
> + return 0;
> +}
> +EXPORT_SYMBOL(nuc900_request_dma);
> +
> +int nuc900_free_dma(const char *dev_name)
> +{
> + struct nuc900_dma *dma = NULL;
> +
> + BUG_ON(!dev_name);
> + WARN_ON(shared_irq_using.counter == 0);
> + spin_lock(&dma_chan_lock);
> + match_dmachan_fromname(dev_name, &dma);
> +
> + if (!dma)
> + return -ENXIO;
> +
> + dma->device = NULL;
> + spin_unlock(&dma_chan_lock);
> +
> + atomic_dec(&shared_irq_using);
> +
> + kzfree(dma->descp);
> + return 0;
> +}
> +EXPORT_SYMBOL(nuc900_free_dma);
> +
> +static unsigned int set_start_cmd(unsigned int start)
> +{
> + unsigned int dscp_cmd;
> +
> + dscp_cmd = 0;
> +
> + if (start) {
> + dscp_cmd = (ORDEN|RUN);
> + dscp_cmd &= ~(NON_DSCRIP|RESET);
> + } else {
> + dscp_cmd = (NON_DSCRIP);
> + }
> + dscp_cmd &= DSCRIPMASK;
> +
> + return dscp_cmd;
> +}
> +
> +static unsigned int set_cmd_info(unsigned int countsize)
> +{
> + unsigned int cmd_info;
> +
> + cmd_info = (countsize >> 2);
> +
> + cmd_info = (((cmd_info & CMDINFOMASK) << 18)|GDMAEN|D_INTS);
> + cmd_info &= ~(GDMAMS|DADIR|SADIR|DAFIX|SAFIX|TWSMASK);
> + cmd_info |= TWS;
> +
> + return cmd_info;
> +
> +}
> +
> +static unsigned int get_descplist_num(unsigned int size, unsigned int *leave)
> +{
> + unsigned int dscp_num, other_num;
> +
> + dscp_num = 0;
> + other_num = 0;
> +
> + dscp_num = size / COUTN_TRANSFER;
> + other_num = size % COUTN_TRANSFER;
> +
> + if (other_num)
> + dscp_num += 1;
> +
> + *leave = other_num;
> +
> + return dscp_num;
> +
> +}
> +
> +int nuc900_start_dma(const char *dev_name, dma_addr_t dma_src,
> + dma_addr_t dma_dst, unsigned int size)
> +{
> + struct nuc900_dma_descp *descp = NULL;
> + struct nuc900_dma *dma = NULL;
> + unsigned int i, dscp_num, other_num, val;
> +
> + BUG_ON((!size|!dev_name));
> +
> + match_dmachan_fromname(dev_name, &dma);
> +
> + if (!dma)
> + return -ENXIO;
> +
> + dscp_num = get_descplist_num(size, &other_num);
> +
> + descp = kzalloc(dscp_num * sizeof(struct nuc900_dma), GFP_KERNEL);
> +
> + if (!descp)
> + return -ENOMEM;
> +
> + dma->descp = descp;
> +
> + for (i = 0; i < dscp_num; i++) {
> + descp->next_descp = set_start_cmd(1);
> + descp->srcaddr = dma_src + COUTN_TRANSFER * i;
> + descp->dstaddr = dma_dst + COUTN_TRANSFER * i;
> + descp->commandinfo = set_cmd_info(COUTN_TRANSFER);
> + descp++;
> + }
> + descp--;
> + descp->next_descp = set_start_cmd(0);
> + descp->commandinfo = set_cmd_info(other_num);
> +
> +
> + val = set_start_cmd(1);
> + val |= (unsigned int)(dma->descp);
> + local_irq_disable();
> + __raw_writel(val, dma->dma_reg + GDMA_GDGA);
> +
> + val = __raw_readl(GDMA_INTCS);
> + val |= (ENTC0F|ENTC1F);
> + __raw_writel(val, GDMA_INTCS);
> + local_irq_enable();
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(nuc900_start_dma);
> +
> +void __init nuc900_init_dma(void)
> +{
> + unsigned i, ret;
> + struct nuc900_dma *dma_channel;
> + spin_lock_init(&dma_chan_lock);
> + for (i = 0; i < NUC900_DMA_CHANNELS; i++) {
> + dma_channel = &dma_chan[i];
> + dma_channel->dma_reg = DMA_BASE + i * CHANNELINERV;
> + dma_channel->device = NULL;
> + }
> + ret = request_irq(IRQ_GDMAGROUP, dma_irq_handler, IRQF_SHARED|
> + IRQF_DISABLED, NULL, NULL);
> + if (ret)
> + printk(KERN_ERR "register dma interrupt error: %d\n", ret);
> + dmachan0 = &dma_chan[0];
> + dmachan1 = &dma_chan[1];
> +}
> diff -uNr b/linux-2.6.32-rc8/arch/arm/mach-w90x900/Makefile
> a/arch/arm/mach-w90x900/Makefile
> --- b/linux-2.6.32-rc8/arch/arm/mach-w90x900/Makefile 2009-11-20
> 06:32:38.000000000 +0800
> +++ a/arch/arm/mach-w90x900/Makefile 2009-12-06 12:34:47.000000000 +0800
> @@ -5,7 +5,7 @@
> # Object file lists.
>
> obj-y := irq.o time.o mfp.o gpio.o clock.o
> -obj-y += clksel.o dev.o cpu.o
> +obj-y += clksel.o dev.o cpu.o dma.o
> # W90X900 CPU support files
>
> obj-$(CONFIG_CPU_W90P910) += nuc910.o
>
--
linux-arm-kernel mailing list
linux-arm-kernel at lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
More information about the linux-arm-kernel
mailing list