[U-Boot] [PATCH v2 1/4] dma: lpc32xx: add DMA driver

[LEMIEUX, SYLVAIN]

Hi Marek,

Thanks for the feedback;

I will look into it and submit an updated version once I get feedback
for the other patches.

> From: U-Boot [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Marek Vasut
>
> On Wednesday, July 29, 2015 at 06:14:07 PM, slemieux.tyco at gmail.com wrote:
> > From: Sylvain Lemieux <slemieux at tycoint.com>
> >
> > Incorporate DMA driver from legacy LPCLinux NXP BSP.
> > The files taken from the legacy patch are:
> > - lpc32xx DMA driver
> > - lpc3250 header file DMA registers definition.
> >
> > The legacy driver was updated to integrate with the latest u-boot.
> >
> > Signed-off-by: Sylvain Lemieux <slemieux at tycoint.com>
>
> [...]
>
> > diff --git a/drivers/dma/lpc32xx_dma.c b/drivers/dma/lpc32xx_dma.c
> > new file mode 100644
> > index 0000000..feb16ce
> > --- /dev/null
> > +++ b/drivers/dma/lpc32xx_dma.c
> > @@ -0,0 +1,153 @@
> > +/*
> > + * Copyright (C) 2008-2015 by NXP Semiconductors
> > + * All rights reserved.
> > + *
> > + * @Author: Kevin Wells
> > + * @Descr: LPC3250 DMA controller interface support functions
> > + *
> > + * See file CREDITS for list of people who contributed to this
> > + * project.
> > + *
> > + * SPDX-License-Identifier:        GPL-2.0+
> > + */
> > +
> > +#include <common.h>
> > +#include <asm/arch/dma.h>
> > +#include <asm/arch/cpu.h>
> > +#include <asm/arch/clk.h>
> > +#include <asm/arch/sys_proto.h>
> > +#include <asm/io.h>
> > +
> > +/* Some optimization stuff */
> > +#ifndef unlikely
> > +#define likely(x)  __builtin_expect(!!(x), 1)
> > +#define unlikely(x)        __builtin_expect(!!(x), 0)
> > +#endif
>
> This is defined in include/compiler.h
>
> > +/* bit position macro */
> > +#define _BIT(n)            (0x1 << (n))
>
> Drop this as well please.
>
> > +/* DMA controller channel register structure */
> > +struct dmac_chan_reg {
> > +   uint32_t src_addr;
> > +   uint32_t dest_addr;
> > +   uint32_t lli;
> > +   uint32_t control;
> > +   uint32_t config_ch;
> > +   uint32_t reserved[3];
> > +};
> > +
> > +/* DMA controller register structures */
> > +struct dma_reg {
> > +   uint32_t int_stat;
> > +   uint32_t int_tc_stat;
> > +   uint32_t int_tc_clear;
> > +   uint32_t int_err_stat;
> > +   uint32_t int_err_clear;
> > +   uint32_t raw_tc_stat;
> > +   uint32_t raw_err_stat;
> > +   uint32_t chan_enable;
> > +   uint32_t sw_burst_req;
> > +   uint32_t sw_single_req;
> > +   uint32_t sw_last_burst_req;
> > +   uint32_t sw_last_single_req;
> > +   uint32_t config;
> > +   uint32_t sync;
> > +   uint32_t reserved[50];
> > +   struct dmac_chan_reg dma_chan[8];
> > +};
> > +
> > +/* Macro pointing to DMA registers */
> > +#define DMA_NO_OF_CHANNELS 8
> > +
> > +/* config register definitions */
> > +#define DMAC_CTRL_ENABLE   (1 << 0) /* For enabling the DMA controller */
> > +
> > +static uint32_t alloc_ch;
> > +
> > +static struct dma_reg *dma = (struct dma_reg *)DMA_BASE;
> > +
> > +int lpc32xx_dma_get_channel(void)
> > +{
> > +   int i;
> > +   uint32_t status = 0;
> > +
> > +   if (!alloc_ch) { /* First time caller */
> > +           /* DMA clock are enable by "lpc32xx_dma_init()" and should
> > +            * be call by board "board_early_init_f()" function. */
> > +
> > +           /* Make sure DMA controller and all channels are disabled.
> > +            * Controller is in little-endian mode. Disable sync signals */
> > +           writel(0, &dma->config);
> > +           writel(0, &dma->sync);
> > +
> > +           /* Clear interrupt and error statuses */
> > +           writel(0xFF, &dma->int_tc_clear);
> > +           writel(0xFF, &dma->raw_tc_stat);
> > +           writel(0xFF, &dma->int_err_clear);
> > +           writel(0xFF, &dma->raw_err_stat);
> > +
> > +           /* Enable DMA controller */
> > +           writel(DMAC_CTRL_ENABLE, &dma->config);
> > +   }
> > +
> > +   for (i = 0; i < DMA_NO_OF_CHANNELS && (status & _BIT(i)); i++)
> > +           ;
>
> I think you should look at ffs() and fls() in include/linux/bitops.h here.
>
> [...]
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