Messages in this thread | | | Subject | Re: [alsa-devel] [PATCH 06/17] soundwire: cadence_master: use firmware defaults for frame shape | From | Cezary Rojewski <> | Date | Tue, 6 Aug 2019 18:06:15 +0200 |
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On 2019-08-06 17:36, Pierre-Louis Bossart wrote: > > > On 8/6/19 10:27 AM, Cezary Rojewski wrote: >> On 2019-08-06 02:55, Pierre-Louis Bossart wrote: >>> diff --git a/drivers/soundwire/cadence_master.c >>> b/drivers/soundwire/cadence_master.c >>> index 5d9729b4d634..89c55e4bb72c 100644 >>> --- a/drivers/soundwire/cadence_master.c >>> +++ b/drivers/soundwire/cadence_master.c >>> @@ -48,6 +48,8 @@ >>> #define CDNS_MCP_SSPSTAT 0xC >>> #define CDNS_MCP_FRAME_SHAPE 0x10 >>> #define CDNS_MCP_FRAME_SHAPE_INIT 0x14 >>> +#define CDNS_MCP_FRAME_SHAPE_COL_MASK GENMASK(2, 0) >>> +#define CDNS_MCP_FRAME_SHAPE_ROW_OFFSET 3 >>> #define CDNS_MCP_CONFIG_UPDATE 0x18 >>> #define CDNS_MCP_CONFIG_UPDATE_BIT BIT(0) >>> @@ -175,7 +177,6 @@ >>> /* Driver defaults */ >>> #define CDNS_DEFAULT_CLK_DIVIDER 0 >>> -#define CDNS_DEFAULT_FRAME_SHAPE 0x30 >>> #define CDNS_DEFAULT_SSP_INTERVAL 0x18 >>> #define CDNS_TX_TIMEOUT 2000 >>> @@ -901,6 +902,20 @@ int sdw_cdns_pdi_init(struct sdw_cdns *cdns, >>> } >>> EXPORT_SYMBOL(sdw_cdns_pdi_init); >>> +static u32 cdns_set_initial_frame_shape(int n_rows, int n_cols) >>> +{ >>> + u32 val; >>> + int c; >>> + int r; >>> + >>> + r = sdw_find_row_index(n_rows); >>> + c = sdw_find_col_index(n_cols) & CDNS_MCP_FRAME_SHAPE_COL_MASK; >>> + >>> + val = (r << CDNS_MCP_FRAME_SHAPE_ROW_OFFSET) | c; >>> + >>> + return val; >>> +} >>> + >> >> Guess this have been said already, but this function could be >> simplified - unless you really want to keep explicit variable >> declaration. Both "c" and "r" declarations could be merged into single >> line while "val" is not needed at all. >> >> One more thing - is AND bitwise op really needed for cols explicitly? >> We know all col values upfront - these are static and declared in >> global table nearby. Static declaration takes care of "initial >> range-check". Is another one necessary? >> >> Moreover, this is a _get_ and certainly not a _set_ type of function. >> I'd even consider renaming it to: "cdns_get_frame_shape" as this is >> neither a _set_ nor an explicit initial frame shape setter. >> >> It might be even helpful to split two usages: >> >> #define sdw_frame_shape(col_idx, row_idx) \ >> ((row_idx << CDNS_MCP_FRAME_SHAPE_ROW_OFFSET) | col_idx) >> >> u32 cdns_get_frame_shape(u16 rows, u16 cols) >> { >> u16 c, r; >> >> r = sdw_find_row_index(rows); >> c = sdw_find_col_index(cols); >> >> return sdw_frame_shape(c, r); >> } >> >> The above may even be simplified into one-liner. > > This is a function used once on startup, there is no real need to > simplify further. The separate variables help add debug traces as needed > and keep the code readable while showing how the values are encoded into > a register.
Eh, I've thought it's gonna be exposed to userspace (via uapi) so it can be fetched by tests or tools.
In such case - if there is a single usage only - guess function is fine as is.
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