[PATCH 12/17] soundwire: cadence_master: make use of mclk_freq property

Pierre-Louis Bossart
2019-08-06T00:55:51Z

Now that the prototype and Intel implementation are enabled, use this
property to avoid hard-coded values.

For example for ICL the mclk_freq value is 38.4 MHz while on CNL/CML
it's 24 MHz. The mclk_freq should not be confused with the
max_clk_freq, which si the maximum bus clock. The mclk_freq is
typically tied to the oscillator frequency and does not change between
platforms. The max_clk_freq value is linked to the maximum bandwidth
needed and topology/trace length.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
---
drivers/soundwire/cadence_master.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c
index 89c55e4bb72c..049ecfad2c00 100644
--- a/drivers/soundwire/cadence_master.c
+++ b/drivers/soundwire/cadence_master.c
@@ -175,8 +175,6 @@
#define CDNS_PDI_CONFIG_PORT GENMASK(4, 0)

/* Driver defaults */
-
-#define CDNS_DEFAULT_CLK_DIVIDER 0
#define CDNS_DEFAULT_SSP_INTERVAL 0x18
#define CDNS_TX_TIMEOUT 2000

@@ -922,7 +920,10 @@ static u32 cdns_set_initial_frame_shape(int n_rows, int n_cols)
*/
int sdw_cdns_init(struct sdw_cdns *cdns)
{
+ struct sdw_bus *bus = &cdns->bus;
+ struct sdw_master_prop *prop = &bus->prop;
u32 val;
+ int divider;
int ret;

/* Exit clock stop */
@@ -934,9 +935,11 @@ int sdw_cdns_init(struct sdw_cdns *cdns)
}

/* Set clock divider */
+ divider = (prop->mclk_freq / prop->max_clk_freq) - 1;
val = cdns_readl(cdns, CDNS_MCP_CLK_CTRL0);
- val |= CDNS_DEFAULT_CLK_DIVIDER;
+ val |= divider;
cdns_writel(cdns, CDNS_MCP_CLK_CTRL0, val);
+ cdns_writel(cdns, CDNS_MCP_CLK_CTRL1, val);

/*
* Frame shape changes after initialization have to be done
@@ -984,6 +987,7 @@ EXPORT_SYMBOL(sdw_cdns_init);

int cdns_bus_conf(struct sdw_bus *bus, struct sdw_bus_params *params)
{
+ struct sdw_master_prop *prop = &bus->prop;
struct sdw_cdns *cdns = bus_to_cdns(bus);
int mcp_clkctrl_off, mcp_clkctrl;
int divider;
@@ -993,7 +997,9 @@ int cdns_bus_conf(struct sdw_bus *bus, struct sdw_bus_params *params)
return -EINVAL;
}

- divider = (params->max_dr_freq / params->curr_dr_freq) - 1;
+ divider = prop->mclk_freq * SDW_DOUBLE_RATE_FACTOR /
+ params->curr_dr_freq;
+ divider--; /* divider is 1/(N+1) */

if (params->next_bank)
mcp_clkctrl_off = CDNS_MCP_CLK_CTRL1;
--
2.20.1