[U-Boot] [PATCH v6 1/5] dma: lpc32xx: add DMA driver

[Vladimir Zapolskiy]

Hi Sylvain,

On 10.08.2015 15:16, 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 and clean-up as part of the integration with the latest u-boot.
> 
> Signed-off-by: Sylvain Lemieux <slemieux at tycoint.com>
> ---
> Changes from v5 to v6:
> * Addressed Marek's comments on LPC32xx DMA driver: 
>   - return "-ETIMEDOUT" on timeout. 
> * Addressed Vladimir's comments on LPC32xx DMA driver:
>   - follow alphabetic order when adding "lpc32xx_dma_init()".
>   - use "writel()" when enabling DMA clock.
>   - move DMAC registers definitions from NAND SLC to "dma.h".
>   - remove support to release DMA channel.
>   - update the API to use an unsigned type for the channel.
>   - return an error instead of generating a fatal BUG when
>     doing a transfer on an unallocated channel.
>   - add an explanatory error when returning with a failure.
> 
> Changes from v4 to v5:
> * Addressed Marek's comments on LPC32xx DMA driver:
>   - Move macro use by the DMA client to write the next
>     DMA linked list item address to NAND SLC driver.
>   - updated "lpc32xx_dma_wait_status()" implementation
>     to make if stetement easier to read.
>   - updated multiline comments style.
> 
> Changes from v3 to v4:
> * Addressed Marek's comments on LPC32xx DMA driver:
>   - updated multiline comments style.
>   - use "u32" instead of "uint32_t".
>   - fixed unbounded loop.
> 
> Changes from v2 to v3:
> * Addressed Marek's comments on LPC32xx DMA driver:
>   - use defined in header file instead of local definition.
>   - remove for loop and use "ffz()".
> * Provide define to assign next DMA linked list item address
>   to removed typecast in DMA client (ex. NAND SLC).
> 
> Changes from v1 to v2:
> * Moved the DMA patch as the first patch of the series.
> * The NAND SLC patch (link below) is applied before this
>   patch: https://patchwork.ozlabs.org/patch/497308/
> 
> Update to the legacy driver to integrate with the latest u-boot:
> 1) Fixed checkpatch script output in legacy code.
> 2) Use LPC32xx definition from "cpu.h" and "clk.h".
> 3) Incorporate DMA specific register definition from "lpc3250.h"
>    header file from legacy BSP patch from LPCLinux.
> 4) Use u-boot API for register access to remove the volatile
>    in register definition taken from "lpc3250.h" header file.
> 5) Add DMA interface to "dma.h".
> 6) Add dma clock control register bits (clk.h).
> 7) Add functions to initialize the DMA clock.
> 
> The legacy BSP patch (u-boot-2009.03_lpc32x0-v1.07.patch.tar.bz2)
> was downloaded from the LPCLinux Web site.
> 
>  arch/arm/cpu/arm926ejs/lpc32xx/devices.c      |   7 ++
>  arch/arm/include/asm/arch-lpc32xx/clk.h       |   3 +
>  arch/arm/include/asm/arch-lpc32xx/dma.h       |  67 ++++++++++++
>  arch/arm/include/asm/arch-lpc32xx/sys_proto.h |   1 +
>  drivers/dma/Makefile                          |   1 +
>  drivers/dma/lpc32xx_dma.c                     | 147 ++++++++++++++++++++++++++
>  6 files changed, 226 insertions(+)
>  create mode 100644 arch/arm/include/asm/arch-lpc32xx/dma.h
>  create mode 100644 drivers/dma/lpc32xx_dma.c
> 
> diff --git a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> index c0c9c6c..f0af851 100644
> --- a/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> +++ b/arch/arm/cpu/arm926ejs/lpc32xx/devices.c
> @@ -41,6 +41,13 @@ void lpc32xx_uart_init(unsigned int uart_id)
>  	       &clk->u3clk + (uart_id - 3));
>  }
>  
> +void lpc32xx_dma_init(void)
> +{
> +	/* Enable DMA interface */
> +	writel(DMA_CLK_ENABLE, &clk->dmaclk_ctrl);
> +
> +}
> +
>  void lpc32xx_mac_init(void)
>  {
>  	/* Enable MAC interface */
> diff --git a/arch/arm/include/asm/arch-lpc32xx/clk.h b/arch/arm/include/asm/arch-lpc32xx/clk.h
> index 010211a..663f6bc 100644
> --- a/arch/arm/include/asm/arch-lpc32xx/clk.h
> +++ b/arch/arm/include/asm/arch-lpc32xx/clk.h
> @@ -158,6 +158,9 @@ struct clk_pm_regs {
>  #define CLK_NAND_SLC_SELECT		(1 << 2)
>  #define CLK_NAND_MLC_INT		(1 << 5)
>  
> +/* DMA Clock Control Register bits */
> +#define DMA_CLK_ENABLE			(1 << 0)
> +

for sake of consistency with all the rest clock name bits, please rename
DMA_CLK_ENABLE to CLK_DMA_ENABLE

> diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
> index 4c8fcc2..f95fe70 100644
> --- a/drivers/dma/Makefile
> +++ b/drivers/dma/Makefile
> @@ -10,3 +10,4 @@ obj-$(CONFIG_APBH_DMA) += apbh_dma.o
>  obj-$(CONFIG_FSL_DMA) += fsl_dma.o
>  obj-$(CONFIG_TI_KSNAV) += keystone_nav.o keystone_nav_cfg.o
>  obj-$(CONFIG_TI_EDMA3) += ti-edma3.o
> +obj-$(CONFIG_DMA_LPC32XX) += lpc32xx_dma.o

Not sure about the ordering policy here, probably appending is good enough.

Tested on non-SPL build with hardware NAND SLC ECC, feel free to add

Tested-by: Vladimir Zapolskiy <vz at mleia.com>

--
With best wishes,
Vladimir