Re: [alsa-devel] [PATCH 14/39] firewire-lib: Add handling output connection by CMP

Takashi Sakamoto wrote:

This patch adds some macros, codes with condition of direction and new functions to handle output connection. Once cmp_connection_init() is executed with its direction, CMP input and output connection can be handled by the same way.

+++ b/sound/firewire/cmp.c +static unsigned long long get_offset(struct cmp_connection *c, bool master) +{

• unsigned long long offset = CSR_REGISTER_BASE;
• if (!master) {

• if (c->direction == CMP_INPUT)
  

• 	offset += CSR_IPCR(c->pcr_index);
  

• else
  

• 	offset += CSR_OPCR(c->pcr_index);
  

• } else {

• if (c->direction == CMP_INPUT)
  

• 	offset += CSR_IMPR;
  

• else
  

• 	offset += CSR_OMPR;
  

• }
• return offset;

+}

This function is always used with a constant master parameter, and the two branches don't really share much code. Two functions would be simpler:

static u64 mpr_address(struct cmp_connection *c) { if (c->direction == CMP_INPUT) return CSR_REGISTER_BASE + CSR_IMPR; else return CSR_REGISTER_BASE + CSR_OMPR; }

static u64 pcr_address(struct cmp_connection *c) { if (c->direction == CMP_INPUT) return CSR_REGISTER_BASE + CSR_IPCR(c->pcr_index); else return CSR_REGISTER_BASE + CSR_OPCR(c->pcr_index); }

Regards, Clemens