[PATCH v7 1/4] clk: meson: add emmc sub clock phase delay driver

From: Jianxin Pan
Date: Thu Nov 15 2018 - 07:18:56 EST


From: Yixun Lan <yixun.lan@xxxxxxxxxxx>

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@xxxxxxxxxxx>
Signed-off-by: Jianxin Pan <jianxin.pan@xxxxxxxxxxx>
---
drivers/clk/meson/Makefile | 2 +-
drivers/clk/meson/clk-phase-delay.c | 64 +++++++++++++++++++++++++++++++++++++
drivers/clk/meson/clkc.h | 13 ++++++++
3 files changed, 78 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 72ec8c4..39ce566 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 0000000..84e7b63
--- /dev/null
+++ b/drivers/clk/meson/clk-phase-delay.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Amlogic Meson MMC Sub Clock Controller Driver
+ *
+ * Copyright (c) 2017 Baylibre SAS.
+ * Author: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yixun Lan <yixun.lan@xxxxxxxxxxx>
+ * Author: Jianxin Pan <jianxin.pan@xxxxxxxxxxx>
+ */
+
+#include <linux/clk-provider.h>
+#include "clkc.h"
+
+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;
+ unsigned long period_ps, p, d;
+ int degrees;
+
+ ph = meson_clk_get_phase_delay_data(clk);
+ p = meson_parm_read(clk->map, &ph->phase);
+ degrees = p * 360 / (1 << (ph->phase.width));
+
+ period_ps = DIV_ROUND_UP(NSEC_PER_SEC * 1000,
+ clk_hw_get_rate(hw));
+
+ d = meson_parm_read(clk->map, &ph->delay);
+ degrees += d * ph->delay_step_ps * 360 / period_ps;
+ degrees %= 360;
+
+ return degrees;
+}
+
+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;
+ unsigned long period_ps, d = 0, r;
+
+ ph = meson_clk_get_phase_delay_data(clk);
+ period_ps = DIV_ROUND_UP(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(degrees, 360 / 1 << (ph->phase.width));
+ d = DIV_ROUND_CLOSEST(r * period_ps,
+ 360 * ph->delay_step_ps);
+ d = min(d, PMASK(ph->delay.width));
+
+ meson_parm_write(clk->map, &ph->phase, degrees);
+ meson_parm_write(clk->map, &ph->delay, 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 6b96d55..30470c6 100644
--- a/drivers/clk/meson/clkc.h
+++ b/drivers/clk/meson/clkc.h
@@ -105,6 +105,18 @@ struct clk_regmap _name = { \
}, \
};

+struct meson_clk_phase_delay_data {
+ struct parm phase;
+ struct parm delay;
+ unsigned int delay_step_ps;
+};
+
+static inline struct meson_clk_phase_delay_data *
+meson_clk_get_phase_delay_data(struct clk_regmap *clk)
+{
+ return clk->data;
+}
+
/* clk_ops */
extern const struct clk_ops meson_clk_pll_ro_ops;
extern const struct clk_ops meson_clk_pll_ops;
@@ -112,5 +124,6 @@ struct clk_regmap _name = { \
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 */
--
1.9.1