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Subject[PATCH v4 1/3] clk: meson: add emmc sub clock phase delay driver
Date
Export the emmc sub clock phase delay ops which will be used
by the emmc sub clock driver itself.

Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
---
drivers/clk/meson/Makefile | 2 +-
drivers/clk/meson/clk-phase-delay.c | 96 +++++++++++++++++++++++++++++
drivers/clk/meson/clkc.h | 13 ++++
3 files changed, 110 insertions(+), 1 deletion(-)
create mode 100644 drivers/clk/meson/clk-phase-delay.c

diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 72ec8c40d848..39ce5661b654 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -2,7 +2,7 @@
# Makefile for Meson specific clk
#

-obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o
+obj-$(CONFIG_COMMON_CLK_AMLOGIC) += clk-pll.o clk-mpll.o clk-phase.o clk-phase-delay.o
obj-$(CONFIG_COMMON_CLK_AMLOGIC_AUDIO) += clk-triphase.o sclk-div.o
obj-$(CONFIG_COMMON_CLK_MESON_AO) += meson-aoclk.o
obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
diff --git a/drivers/clk/meson/clk-phase-delay.c b/drivers/clk/meson/clk-phase-delay.c
new file mode 100644
index 000000000000..6f226814cfec
--- /dev/null
+++ b/drivers/clk/meson/clk-phase-delay.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Amlogic Meson MMC Sub Clock Controller Driver
+ *
+ * Copyright (c) 2017 Baylibre SAS.
+ * Author: Jerome Brunet <jbrunet@baylibre.com>
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yixun Lan <yixun.lan@amlogic.com>
+ */
+
+#include <linux/clk-provider.h>
+#include "clkc.h"
+
+#define SD_EMMC_CLOCK 0
+
+static int meson_clk_phase_delay_get_phase(struct clk_hw *hw)
+{
+ struct clk_regmap *clk = to_clk_regmap(hw);
+ struct meson_clk_phase_delay_data *ph =
+ meson_clk_get_phase_delay_data(clk);
+ unsigned int phase_num = 1 << hweight_long(ph->phase_mask);
+ unsigned long period_ps, p, d;
+ int degrees;
+ u32 val;
+
+ regmap_read(clk->map, SD_EMMC_CLOCK, &val);
+ p = (val & ph->phase_mask) >> __ffs(ph->phase_mask);
+ degrees = p * 360 / phase_num;
+
+ if (ph->delay_mask) {
+ period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
+ clk_hw_get_rate(hw));
+ d = (val & ph->delay_mask) >> __ffs(ph->delay_mask);
+ degrees += d * ph->delay_step_ps * 360 / period_ps;
+ degrees %= 360;
+ }
+
+ return degrees;
+}
+
+static void meson_clk_apply_phase_delay(struct clk_regmap *clk,
+ unsigned int phase,
+ unsigned int delay)
+{
+ struct meson_clk_phase_delay_data *ph = clk->data;
+ u32 val;
+
+ regmap_read(clk->map, SD_EMMC_CLOCK, &val);
+
+ val &= ~ph->phase_mask;
+ val |= phase << __ffs(ph->phase_mask);
+
+ if (ph->delay_mask) {
+ val &= ~ph->delay_mask;
+ val |= delay << __ffs(ph->delay_mask);
+ }
+
+ regmap_write(clk->map, SD_EMMC_CLOCK, val);
+}
+
+static int meson_clk_phase_delay_set_phase(struct clk_hw *hw, int degrees)
+{
+ struct clk_regmap *clk = to_clk_regmap(hw);
+ struct meson_clk_phase_delay_data *ph =
+ meson_clk_get_phase_delay_data(clk);
+ unsigned int phase_num = 1 << hweight_long(ph->phase_mask);
+ unsigned long period_ps, d = 0, r;
+ u64 p;
+
+ p = degrees % 360;
+
+ if (!ph->delay_mask) {
+ p = DIV_ROUND_CLOSEST_ULL(p, 360 / phase_num);
+ } else {
+ period_ps = DIV_ROUND_UP((unsigned long)NSEC_PER_SEC * 1000,
+ clk_hw_get_rate(hw));
+
+ /* First compute the phase index (p), the remainder (r) is the
+ * part we'll try to acheive using the delays (d).
+ */
+ r = do_div(p, 360 / phase_num);
+ d = DIV_ROUND_CLOSEST(r * period_ps,
+ 360 * ph->delay_step_ps);
+ d = min(d, ph->delay_mask >> __ffs(ph->delay_mask));
+ }
+
+ meson_clk_apply_phase_delay(clk, p, d);
+ return 0;
+}
+
+const struct clk_ops meson_clk_phase_delay_ops = {
+ .get_phase = meson_clk_phase_delay_get_phase,
+ .set_phase = meson_clk_phase_delay_set_phase,
+};
+EXPORT_SYMBOL_GPL(meson_clk_phase_delay_ops);
diff --git a/drivers/clk/meson/clkc.h b/drivers/clk/meson/clkc.h
index 24cec16b6038..499834dd34f2 100644
--- a/drivers/clk/meson/clkc.h
+++ b/drivers/clk/meson/clkc.h
@@ -113,6 +113,18 @@ struct clk_regmap _name = { \
}, \
};

+struct meson_clk_phase_delay_data {
+ unsigned long phase_mask;
+ unsigned long delay_mask;
+ unsigned int delay_step_ps;
+};
+
+static inline struct meson_clk_phase_delay_data *
+meson_clk_get_phase_delay_data(struct clk_regmap *clk)
+{
+ return (struct meson_clk_phase_delay_data *)clk->data;
+}
+
/* clk_ops */
extern const struct clk_ops meson_clk_pll_ro_ops;
extern const struct clk_ops meson_clk_pll_ops;
@@ -120,5 +132,6 @@ extern const struct clk_ops meson_clk_cpu_ops;
extern const struct clk_ops meson_clk_mpll_ro_ops;
extern const struct clk_ops meson_clk_mpll_ops;
extern const struct clk_ops meson_clk_phase_ops;
+extern const struct clk_ops meson_clk_phase_delay_ops;

#endif /* __CLKC_H */
--
2.17.1
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