clk: qcom: Support display RCG clocks

Add support for the DSI/EDP/HDMI RCG clocks. With the proper
display driver in place this should allow us to support display
clocks on msm8974 based devices.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

drivers/clk/qcom/clk-rcg.h

@@ -155,5 +155,8 @@ struct clk_rcg2 {
 #define to_clk_rcg2(_hw) container_of(to_clk_regmap(_hw), struct clk_rcg2, clkr)
 
 extern const struct clk_ops clk_rcg2_ops;
+extern const struct clk_ops clk_edp_pixel_ops;
+extern const struct clk_ops clk_byte_ops;
+extern const struct clk_ops clk_pixel_ops;
 
 #endif

drivers/clk/qcom/clk-rcg2.c

@@ -19,6 +19,7 @@
 #include <linux/clk-provider.h>
 #include <linux/delay.h>
 #include <linux/regmap.h>
+#include <linux/math64.h>
 
 #include <asm/div64.h>
 
@@ -225,31 +226,25 @@ static long clk_rcg2_determine_rate(struct clk_hw *hw, unsigned long rate,
 	return _freq_tbl_determine_rate(hw, rcg->freq_tbl, rate, p_rate, p);
 }
 
-static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
+static int clk_rcg2_configure(struct clk_rcg2 *rcg, const struct freq_tbl *f)
 {
-	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
-	const struct freq_tbl *f;
 	u32 cfg, mask;
 	int ret;
 
-	f = find_freq(rcg->freq_tbl, rate);
-	if (!f)
-		return -EINVAL;
-
 	if (rcg->mnd_width && f->n) {
 		mask = BIT(rcg->mnd_width) - 1;
-		ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + M_REG,
-					 mask, f->m);
+		ret = regmap_update_bits(rcg->clkr.regmap,
+				rcg->cmd_rcgr + M_REG, mask, f->m);
 		if (ret)
 			return ret;
 
-		ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + N_REG,
-					 mask, ~(f->n - f->m));
+		ret = regmap_update_bits(rcg->clkr.regmap,
+				rcg->cmd_rcgr + N_REG, mask, ~(f->n - f->m));
 		if (ret)
 			return ret;
 
-		ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + D_REG,
-					 mask, ~f->n);
+		ret = regmap_update_bits(rcg->clkr.regmap,
+				rcg->cmd_rcgr + D_REG, mask, ~f->n);
 		if (ret)
 			return ret;
 	}
@@ -260,14 +255,26 @@ static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
 	cfg |= rcg->parent_map[f->src] << CFG_SRC_SEL_SHIFT;
 	if (rcg->mnd_width && f->n)
 		cfg |= CFG_MODE_DUAL_EDGE;
-	ret = regmap_update_bits(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG, mask,
-			cfg);
+	ret = regmap_update_bits(rcg->clkr.regmap,
+			rcg->cmd_rcgr + CFG_REG, mask, cfg);
 	if (ret)
 		return ret;
 
 	return update_config(rcg);
 }
 
+static int __clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+	const struct freq_tbl *f;
+
+	f = find_freq(rcg->freq_tbl, rate);
+	if (!f)
+		return -EINVAL;
+
+	return clk_rcg2_configure(rcg, f);
+}
+
 static int clk_rcg2_set_rate(struct clk_hw *hw, unsigned long rate,
 			    unsigned long parent_rate)
 {
@@ -290,3 +297,265 @@ const struct clk_ops clk_rcg2_ops = {
 	.set_rate_and_parent = clk_rcg2_set_rate_and_parent,
 };
 EXPORT_SYMBOL_GPL(clk_rcg2_ops);
+
+struct frac_entry {
+	int num;
+	int den;
+};
+
+static const struct frac_entry frac_table_675m[] = {	/* link rate of 270M */
+	{ 52, 295 },	/* 119 M */
+	{ 11, 57 },	/* 130.25 M */
+	{ 63, 307 },	/* 138.50 M */
+	{ 11, 50 },	/* 148.50 M */
+	{ 47, 206 },	/* 154 M */
+	{ 31, 100 },	/* 205.25 M */
+	{ 107, 269 },	/* 268.50 M */
+	{ },
+};
+
+static struct frac_entry frac_table_810m[] = { /* Link rate of 162M */
+	{ 31, 211 },	/* 119 M */
+	{ 32, 199 },	/* 130.25 M */
+	{ 63, 307 },	/* 138.50 M */
+	{ 11, 60 },	/* 148.50 M */
+	{ 50, 263 },	/* 154 M */
+	{ 31, 120 },	/* 205.25 M */
+	{ 119, 359 },	/* 268.50 M */
+	{ },
+};
+
+static int clk_edp_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
+			      unsigned long parent_rate)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+	struct freq_tbl f = *rcg->freq_tbl;
+	const struct frac_entry *frac;
+	int delta = 100000;
+	s64 src_rate = parent_rate;
+	s64 request;
+	u32 mask = BIT(rcg->hid_width) - 1;
+	u32 hid_div;
+
+	if (src_rate == 810000000)
+		frac = frac_table_810m;
+	else
+		frac = frac_table_675m;
+
+	for (; frac->num; frac++) {
+		request = rate;
+		request *= frac->den;
+		request = div_s64(request, frac->num);
+		if ((src_rate < (request - delta)) ||
+		    (src_rate > (request + delta)))
+			continue;
+
+		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
+				&hid_div);
+		f.pre_div = hid_div;
+		f.pre_div >>= CFG_SRC_DIV_SHIFT;
+		f.pre_div &= mask;
+		f.m = frac->num;
+		f.n = frac->den;
+
+		return clk_rcg2_configure(rcg, &f);
+	}
+
+	return -EINVAL;
+}
+
+static int clk_edp_pixel_set_rate_and_parent(struct clk_hw *hw,
+		unsigned long rate, unsigned long parent_rate, u8 index)
+{
+	/* Parent index is set statically in frequency table */
+	return clk_edp_pixel_set_rate(hw, rate, parent_rate);
+}
+
+static long clk_edp_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
+				 unsigned long *p_rate, struct clk **p)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+	const struct freq_tbl *f = rcg->freq_tbl;
+	const struct frac_entry *frac;
+	int delta = 100000;
+	s64 src_rate = *p_rate;
+	s64 request;
+	u32 mask = BIT(rcg->hid_width) - 1;
+	u32 hid_div;
+
+	/* Force the correct parent */
+	*p = clk_get_parent_by_index(hw->clk, f->src);
+
+	if (src_rate == 810000000)
+		frac = frac_table_810m;
+	else
+		frac = frac_table_675m;
+
+	for (; frac->num; frac++) {
+		request = rate;
+		request *= frac->den;
+		request = div_s64(request, frac->num);
+		if ((src_rate < (request - delta)) ||
+		    (src_rate > (request + delta)))
+			continue;
+
+		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
+				&hid_div);
+		hid_div >>= CFG_SRC_DIV_SHIFT;
+		hid_div &= mask;
+
+		return calc_rate(src_rate, frac->num, frac->den, !!frac->den,
+				 hid_div);
+	}
+
+	return -EINVAL;
+}
+
+const struct clk_ops clk_edp_pixel_ops = {
+	.is_enabled = clk_rcg2_is_enabled,
+	.get_parent = clk_rcg2_get_parent,
+	.set_parent = clk_rcg2_set_parent,
+	.recalc_rate = clk_rcg2_recalc_rate,
+	.set_rate = clk_edp_pixel_set_rate,
+	.set_rate_and_parent = clk_edp_pixel_set_rate_and_parent,
+	.determine_rate = clk_edp_pixel_determine_rate,
+};
+EXPORT_SYMBOL_GPL(clk_edp_pixel_ops);
+
+static long clk_byte_determine_rate(struct clk_hw *hw, unsigned long rate,
+			 unsigned long *p_rate, struct clk **p)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+	const struct freq_tbl *f = rcg->freq_tbl;
+	unsigned long parent_rate, div;
+	u32 mask = BIT(rcg->hid_width) - 1;
+
+	if (rate == 0)
+		return -EINVAL;
+
+	*p = clk_get_parent_by_index(hw->clk, f->src);
+	*p_rate = parent_rate = __clk_round_rate(*p, rate);
+
+	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
+	div = min_t(u32, div, mask);
+
+	return calc_rate(parent_rate, 0, 0, 0, div);
+}
+
+static int clk_byte_set_rate(struct clk_hw *hw, unsigned long rate,
+			 unsigned long parent_rate)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+	struct freq_tbl f = *rcg->freq_tbl;
+	unsigned long div;
+	u32 mask = BIT(rcg->hid_width) - 1;
+
+	div = DIV_ROUND_UP((2 * parent_rate), rate) - 1;
+	div = min_t(u32, div, mask);
+
+	f.pre_div = div;
+
+	return clk_rcg2_configure(rcg, &f);
+}
+
+static int clk_byte_set_rate_and_parent(struct clk_hw *hw,
+		unsigned long rate, unsigned long parent_rate, u8 index)
+{
+	/* Parent index is set statically in frequency table */
+	return clk_byte_set_rate(hw, rate, parent_rate);
+}
+
+const struct clk_ops clk_byte_ops = {
+	.is_enabled = clk_rcg2_is_enabled,
+	.get_parent = clk_rcg2_get_parent,
+	.set_parent = clk_rcg2_set_parent,
+	.recalc_rate = clk_rcg2_recalc_rate,
+	.set_rate = clk_byte_set_rate,
+	.set_rate_and_parent = clk_byte_set_rate_and_parent,
+	.determine_rate = clk_byte_determine_rate,
+};
+EXPORT_SYMBOL_GPL(clk_byte_ops);
+
+static const struct frac_entry frac_table_pixel[] = {
+	{ 3, 8 },
+	{ 2, 9 },
+	{ 4, 9 },
+	{ 1, 1 },
+	{ }
+};
+
+static long clk_pixel_determine_rate(struct clk_hw *hw, unsigned long rate,
+				 unsigned long *p_rate, struct clk **p)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+	unsigned long request, src_rate;
+	int delta = 100000;
+	const struct freq_tbl *f = rcg->freq_tbl;
+	const struct frac_entry *frac = frac_table_pixel;
+	struct clk *parent = *p = clk_get_parent_by_index(hw->clk, f->src);
+
+	for (; frac->num; frac++) {
+		request = (rate * frac->den) / frac->num;
+
+		src_rate = __clk_round_rate(parent, request);
+		if ((src_rate < (request - delta)) ||
+			(src_rate > (request + delta)))
+			continue;
+
+		*p_rate = src_rate;
+		return (src_rate * frac->num) / frac->den;
+	}
+
+	return -EINVAL;
+}
+
+static int clk_pixel_set_rate(struct clk_hw *hw, unsigned long rate,
+		unsigned long parent_rate)
+{
+	struct clk_rcg2 *rcg = to_clk_rcg2(hw);
+	struct freq_tbl f = *rcg->freq_tbl;
+	const struct frac_entry *frac = frac_table_pixel;
+	unsigned long request, src_rate;
+	int delta = 100000;
+	u32 mask = BIT(rcg->hid_width) - 1;
+	u32 hid_div;
+	struct clk *parent = clk_get_parent_by_index(hw->clk, f.src);
+
+	for (; frac->num; frac++) {
+		request = (rate * frac->den) / frac->num;
+
+		src_rate = __clk_round_rate(parent, request);
+		if ((src_rate < (request - delta)) ||
+			(src_rate > (request + delta)))
+			continue;
+
+		regmap_read(rcg->clkr.regmap, rcg->cmd_rcgr + CFG_REG,
+				&hid_div);
+		f.pre_div = hid_div;
+		f.pre_div >>= CFG_SRC_DIV_SHIFT;
+		f.pre_div &= mask;
+		f.m = frac->num;
+		f.n = frac->den;
+
+		return clk_rcg2_configure(rcg, &f);
+	}
+	return -EINVAL;
+}
+
+static int clk_pixel_set_rate_and_parent(struct clk_hw *hw, unsigned long rate,
+		unsigned long parent_rate, u8 index)
+{
+	/* Parent index is set statically in frequency table */
+	return clk_pixel_set_rate(hw, rate, parent_rate);
+}
+
+const struct clk_ops clk_pixel_ops = {
+	.is_enabled = clk_rcg2_is_enabled,
+	.get_parent = clk_rcg2_get_parent,
+	.set_parent = clk_rcg2_set_parent,
+	.recalc_rate = clk_rcg2_recalc_rate,
+	.set_rate = clk_pixel_set_rate,
+	.set_rate_and_parent = clk_pixel_set_rate_and_parent,
+	.determine_rate = clk_pixel_determine_rate,
+};
+EXPORT_SYMBOL_GPL(clk_pixel_ops);