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>

2 files changed, 287 insertions, 15 deletions

diff --git a/drivers/clk/qcom/clk-rcg.h b/drivers/clk/qcom/clk-rcg.h
index 1d6b6dece328..b9ec11dfd1b4 100644
--- a/drivers/clk/qcom/clk-rcg.h
+++ b/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
diff --git a/drivers/clk/qcom/clk-rcg2.c b/drivers/clk/qcom/clk-rcg2.c
index cbecaec30562..cd185d5cc67a 100644
--- a/drivers/clk/qcom/clk-rcg2.c
+++ b/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);