ASoC: Intel: Skylake: Parse nhlt and register clock device

When NHLT endpoint is present for a SSP then we create clock for that SSP.

MCLK is consistent across endpoints and configuration for an SSP, so query
only for first endpoint for an SSP.

For SCLK/SCLKFS, the best fit is queried from the NHLT configurations which
matches the clock rate requested. Best fit is decided based on below:

1. If rate matches with multiple configurations, then the first
   configuration is selected.

2. If for a selected fs and bits_per_sample, there are multiple endpoint
   configuration match, then the configuration with max number of
   channels is selected. So, the user has to set the rate which fits
   max number of channels

So we create a platform device and pass clock information parsed as
platform data.

Signed-off-by: Sriram Periyasamy <sriramx.periyasamy@intel.com>
Signed-off-by: Jaikrishna Nemallapudi <jaikrishnax.nemallapudi@intel.com>
Signed-off-by: Subhransu S. Prusty <subhransu.s.prusty@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 155 insertions, 0 deletions

diff --git a/sound/soc/intel/skylake/skl-nhlt.c b/sound/soc/intel/skylake/skl-nhlt.c
index e7d766d56c8e..4d2136c0389a 100644
--- a/sound/soc/intel/skylake/skl-nhlt.c
+++ b/sound/soc/intel/skylake/skl-nhlt.c
@@ -19,6 +19,7 @@
  */
 #include <linux/pci.h>
 #include "skl.h"
+#include "skl-i2s.h"
 
 /* Unique identification for getting NHLT blobs */
 static guid_t osc_guid =
@@ -262,3 +263,157 @@ void skl_nhlt_remove_sysfs(struct skl *skl)
 
 	sysfs_remove_file(&dev->kobj, &dev_attr_platform_id.attr);
 }
+
+/*
+ * Queries NHLT for all the fmt configuration for a particular endpoint and
+ * stores all possible rates supported in a rate table for the corresponding
+ * sclk/sclkfs.
+ */
+void skl_get_ssp_clks(struct skl *skl, struct skl_ssp_clk *ssp_clks,
+				struct nhlt_fmt *fmt, u8 id)
+{
+	struct skl_i2s_config_blob_legacy *i2s_config;
+	struct skl_clk_parent_src *parent;
+	struct skl_ssp_clk *sclk, *sclkfs;
+	struct nhlt_fmt_cfg *fmt_cfg;
+	struct wav_fmt_ext *wav_fmt;
+	unsigned long rate = 0;
+	bool present = false;
+	int rate_index = 0;
+	u16 channels, bps;
+	u8 clk_src;
+	int i, j;
+	u32 fs;
+
+	sclk = &ssp_clks[SKL_SCLK_OFS];
+	sclkfs = &ssp_clks[SKL_SCLKFS_OFS];
+
+	if (fmt->fmt_count == 0)
+		return;
+
+	for (i = 0; i < fmt->fmt_count; i++) {
+		fmt_cfg = &fmt->fmt_config[i];
+		wav_fmt = &fmt_cfg->fmt_ext;
+
+		channels = wav_fmt->fmt.channels;
+		bps = wav_fmt->fmt.bits_per_sample;
+		fs = wav_fmt->fmt.samples_per_sec;
+
+		/*
+		 * In case of TDM configuration on a ssp, there can
+		 * be more than one blob in which channel masks are
+		 * different for each usecase for a specific rate and bps.
+		 * But the sclk rate will be generated for the total
+		 * number of channels used for that endpoint.
+		 *
+		 * So for the given fs and bps, choose blob which has
+		 * the superset of all channels for that endpoint and
+		 * derive the rate.
+		 */
+		for (j = i; j < fmt->fmt_count; j++) {
+			fmt_cfg = &fmt->fmt_config[j];
+			wav_fmt = &fmt_cfg->fmt_ext;
+			if ((fs == wav_fmt->fmt.samples_per_sec) &&
+			   (bps == wav_fmt->fmt.bits_per_sample))
+				channels = max_t(u16, channels,
+						wav_fmt->fmt.channels);
+		}
+
+		rate = channels * bps * fs;
+
+		/* check if the rate is added already to the given SSP's sclk */
+		for (j = 0; (sclk[id].rate_cfg[j].rate != 0) &&
+				(j < SKL_MAX_CLK_RATES); j++) {
+			if (sclk[id].rate_cfg[j].rate == rate) {
+				present = true;
+				break;
+			}
+		}
+
+		/* Fill rate and parent for sclk/sclkfs */
+		if (!present) {
+			/* MCLK Divider Source Select */
+			i2s_config = (struct skl_i2s_config_blob_legacy *)
+						fmt->fmt_config[0].config.caps;
+			clk_src = ((i2s_config->mclk.mdivctrl)
+					& SKL_MNDSS_DIV_CLK_SRC_MASK) >>
+					SKL_SHIFT(SKL_MNDSS_DIV_CLK_SRC_MASK);
+
+			parent = skl_get_parent_clk(clk_src);
+
+			/*
+			 * Do not copy the config data if there is no parent
+			 * clock available for this clock source select
+			 */
+			if (!parent)
+				continue;
+
+			sclk[id].rate_cfg[rate_index].rate = rate;
+			sclk[id].rate_cfg[rate_index].config = fmt_cfg;
+			sclkfs[id].rate_cfg[rate_index].rate = rate;
+			sclkfs[id].rate_cfg[rate_index].config = fmt_cfg;
+			sclk[id].parent_name = parent->name;
+			sclkfs[id].parent_name = parent->name;
+
+			rate_index++;
+		}
+	}
+}
+
+void skl_get_mclk(struct skl *skl, struct skl_ssp_clk *mclk,
+				struct nhlt_fmt *fmt, u8 id)
+{
+	struct skl_i2s_config_blob_legacy *i2s_config;
+	struct nhlt_specific_cfg *fmt_cfg;
+	struct skl_clk_parent_src *parent;
+	u32 clkdiv, div_ratio;
+	u8 clk_src;
+
+	fmt_cfg = &fmt->fmt_config[0].config;
+	i2s_config = (struct skl_i2s_config_blob_legacy *)fmt_cfg->caps;
+
+	/* MCLK Divider Source Select */
+	clk_src = ((i2s_config->mclk.mdivctrl) & SKL_MCLK_DIV_CLK_SRC_MASK) >>
+					SKL_SHIFT(SKL_MCLK_DIV_CLK_SRC_MASK);
+
+	clkdiv = i2s_config->mclk.mdivr & SKL_MCLK_DIV_RATIO_MASK;
+
+	/* bypass divider */
+	div_ratio = 1;
+
+	if (clkdiv != SKL_MCLK_DIV_RATIO_MASK)
+		/* Divider is 2 + clkdiv */
+		div_ratio = clkdiv + 2;
+
+	/* Calculate MCLK rate from source using div value */
+	parent = skl_get_parent_clk(clk_src);
+	if (!parent)
+		return;
+
+	mclk[id].rate_cfg[0].rate = parent->rate/div_ratio;
+	mclk[id].rate_cfg[0].config = &fmt->fmt_config[0];
+	mclk[id].parent_name = parent->name;
+}
+
+void skl_get_clks(struct skl *skl, struct skl_ssp_clk *ssp_clks)
+{
+	struct nhlt_acpi_table *nhlt = (struct nhlt_acpi_table *)skl->nhlt;
+	struct nhlt_endpoint *epnt;
+	struct nhlt_fmt *fmt;
+	int i;
+	u8 id;
+
+	epnt = (struct nhlt_endpoint *)nhlt->desc;
+	for (i = 0; i < nhlt->endpoint_count; i++) {
+		if (epnt->linktype == NHLT_LINK_SSP) {
+			id = epnt->virtual_bus_id;
+
+			fmt = (struct nhlt_fmt *)(epnt->config.caps
+					+ epnt->config.size);
+
+			skl_get_ssp_clks(skl, ssp_clks, fmt, id);
+			skl_get_mclk(skl, ssp_clks, fmt, id);
+		}
+		epnt = (struct nhlt_endpoint *)((u8 *)epnt + epnt->length);
+	}
+}