Merge tag 'qcom-geni-immutable-for-mark-brown' of git://git.kernel.org/pub/scm/linux/kernel/git/agross/linux into spi-4.20

Immutable branch for QCOM Geni patches

drivers/soc/qcom/qcom-geni-se.c

···
  */
 int geni_se_clk_tbl_get(struct geni_se *se, unsigned long **tbl)
 {
-	unsigned long freq = 0;
+	long freq = 0;
 	int i;
 
 	if (se->clk_perf_tbl) {
···
 
 	for (i = 0; i < MAX_CLK_PERF_LEVEL; i++) {
 		freq = clk_round_rate(se->clk, freq + 1);
-		if (!freq || freq == se->clk_perf_tbl[i - 1])
+		if (freq <= 0 || freq == se->clk_perf_tbl[i - 1])
 			break;
 		se->clk_perf_tbl[i] = freq;
 	}
···
  * @se:		Pointer to the concerned serial engine.
  * @req_freq:	Requested clock frequency.
  * @index:	Index of the resultant frequency in the table.
- * @res_freq:	Resultant frequency which matches or is closer to the
- *		requested frequency.
+ * @res_freq:	Resultant frequency of the source clock.
  * @exact:	Flag to indicate exact multiple requirement of the requested
  *		frequency.
  *
- * This function is called by the protocol drivers to determine the matching
- * or exact multiple of the requested frequency, as provided by the serial
- * engine clock in order to meet the performance requirements. If there is
- * no matching or exact multiple of the requested frequency found, then it
- * selects the closest floor frequency, if exact flag is not set.
+ * This function is called by the protocol drivers to determine the best match
+ * of the requested frequency as provided by the serial engine clock in order
+ * to meet the performance requirements.
+ *
+ * If we return success:
+ * - if @exact is true  then @res_freq / <an_integer> == @req_freq
+ * - if @exact is false then @res_freq / <an_integer> <= @req_freq
  *
  * Return: 0 on success, standard Linux error codes on failure.
  */
···
 	unsigned long *tbl;
 	int num_clk_levels;
 	int i;
+	unsigned long best_delta;
+	unsigned long new_delta;
+	unsigned int divider;
 
 	num_clk_levels = geni_se_clk_tbl_get(se, &tbl);
 	if (num_clk_levels < 0)
···
 	if (num_clk_levels == 0)
 		return -EINVAL;
 
-	*res_freq = 0;
+	best_delta = ULONG_MAX;
 	for (i = 0; i < num_clk_levels; i++) {
-		if (!(tbl[i] % req_freq)) {
+		divider = DIV_ROUND_UP(tbl[i], req_freq);
+		new_delta = req_freq - tbl[i] / divider;
+		if (new_delta < best_delta) {
+			/* We have a new best! */
 			*index = i;
 			*res_freq = tbl[i];
-			return 0;
-		}
 
-		if (!(*res_freq) || ((tbl[i] > *res_freq) &&
-				     (tbl[i] < req_freq))) {
-			*index = i;
-			*res_freq = tbl[i];
+			/* If the new best is exact then we're done */
+			if (new_delta == 0)
+				return 0;
+
+			/* Record how close we got */
+			best_delta = new_delta;
 		}
 	}
 

include/linux/qcom-geni-se.h

···
 #define HW_VER_MINOR_SHFT		16
 #define HW_VER_STEP_MASK		GENMASK(15, 0)
 
+#define GENI_SE_VERSION_MAJOR(ver) ((ver & HW_VER_MAJOR_MASK) >> HW_VER_MAJOR_SHFT)
+#define GENI_SE_VERSION_MINOR(ver) ((ver & HW_VER_MINOR_MASK) >> HW_VER_MINOR_SHFT)
+#define GENI_SE_VERSION_STEP(ver) (ver & HW_VER_STEP_MASK)
+
 #if IS_ENABLED(CONFIG_QCOM_GENI_SE)
 
 u32 geni_se_get_qup_hw_version(struct geni_se *se);
-
-#define geni_se_get_wrapper_version(se, major, minor, step) do { \
-	u32 ver; \
-\
-	ver = geni_se_get_qup_hw_version(se); \
-	major = (ver & HW_VER_MAJOR_MASK) >> HW_VER_MAJOR_SHFT; \
-	minor = (ver & HW_VER_MINOR_MASK) >> HW_VER_MINOR_SHFT; \
-	step = version & HW_VER_STEP_MASK; \
-} while (0)
 
 /**
  * geni_se_read_proto() - Read the protocol configured for a serial engine