lkml.org 
[lkml]   [2019]   [Sep]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2 08/14] dmaengine: ti: New driver for K3 UDMA - split#1: defines, structs, io func
From
Date


On 30/07/2019 12:34, Peter Ujfalusi wrote:
> Split patch for review containing: defines, structs, io and low level
> functions and interrupt callbacks.
>
> DMA driver for
> Texas Instruments K3 NAVSS Unified DMA – Peripheral Root Complex (UDMA-P)
>
> The UDMA-P is intended to perform similar (but significantly upgraded) functions
> as the packet-oriented DMA used on previous SoC devices. The UDMA-P module
> supports the transmission and reception of various packet types. The UDMA-P is
> architected to facilitate the segmentation and reassembly of SoC DMA data
> structure compliant packets to/from smaller data blocks that are natively
> compatible with the specific requirements of each connected peripheral. Multiple
> Tx and Rx channels are provided within the DMA which allow multiple segmentation
> or reassembly operations to be ongoing. The DMA controller maintains state
> information for each of the channels which allows packet segmentation and
> reassembly operations to be time division multiplexed between channels in order
> to share the underlying DMA hardware. An external DMA scheduler is used to
> control the ordering and rate at which this multiplexing occurs for Transmit
> operations. The ordering and rate of Receive operations is indirectly controlled
> by the order in which blocks are pushed into the DMA on the Rx PSI-L interface.
>
> The UDMA-P also supports acting as both a UTC and UDMA-C for its internal
> channels. Channels in the UDMA-P can be configured to be either Packet-Based or
> Third-Party channels on a channel by channel basis.
>
> The initial driver supports:
> - MEM_TO_MEM (TR mode)
> - DEV_TO_MEM (Packet / TR mode)
> - MEM_TO_DEV (Packet / TR mode)
> - Cyclic (Packet / TR mode)
> - Metadata for descriptors
>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
> ---

[...]

> +
> +/* Generic register access functions */
> +static inline u32 udma_read(void __iomem *base, int reg)
> +{
> + return __raw_readl(base + reg);
> +}
> +
> +static inline void udma_write(void __iomem *base, int reg, u32 val)
> +{
> + __raw_writel(val, base + reg);
> +}
> +
> +static inline void udma_update_bits(void __iomem *base, int reg,
> + u32 mask, u32 val)
> +{
> + u32 tmp, orig;
> +
> + orig = __raw_readl(base + reg);
> + tmp = orig & ~mask;
> + tmp |= (val & mask);
> +
> + if (tmp != orig)
> + __raw_writel(tmp, base + reg);
> +}

Pls, do not use _raw APIs in drivers.

[...]

--
Best regards,
grygorii

\
 
 \ /
  Last update: 2019-09-10 09:29    [W:0.155 / U:1.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site