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Subject[PATCH v2 3/3] clk: meson: add sub MMC clock controller driver
Date
The patch will add a MMC clock controller driver which used by MMC or NAND,
It provide a mux and divider clock, and three phase clocks - core, tx, tx.

Two clocks are provided as the parent of MMC clock controller from
upper layer clock controller - eg "amlogic,axg-clkc" in AXG platform.

To specify which clock the MMC or NAND driver may consume,
the preprocessor macros in the dt-bindings/clock/emmc-clkc.h header
can be used in the device tree sources.

Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
---
drivers/clk/meson/Kconfig | 9 +
drivers/clk/meson/Makefile | 1 +
drivers/clk/meson/mmc-clkc.c | 419 +++++++++++++++++++++++++++++++++++
3 files changed, 429 insertions(+)
create mode 100644 drivers/clk/meson/mmc-clkc.c

diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
index efaa70f682b4..edc18e65c89b 100644
--- a/drivers/clk/meson/Kconfig
+++ b/drivers/clk/meson/Kconfig
@@ -15,6 +15,15 @@ config COMMON_CLK_MESON_AO
select COMMON_CLK_REGMAP_MESON
select RESET_CONTROLLER

+config COMMON_CLK_MMC_MESON
+ tristate "Meson MMC Sub Clock Controller Driver"
+ depends on COMMON_CLK_AMLOGIC
+ select MFD_SYSCON
+ select REGMAP
+ help
+ Support for the MMC sub clock controller on Amlogic Meson Platform,
+ Say Y if you want this clock enabled.
+
config COMMON_CLK_REGMAP_MESON
bool
select REGMAP
diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
index 72ec8c40d848..4b3817f80ba1 100644
--- a/drivers/clk/meson/Makefile
+++ b/drivers/clk/meson/Makefile
@@ -9,4 +9,5 @@ obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o
obj-$(CONFIG_COMMON_CLK_AXG) += axg.o axg-aoclk.o
obj-$(CONFIG_COMMON_CLK_AXG_AUDIO) += axg-audio.o
+obj-$(CONFIG_COMMON_CLK_MMC_MESON) += mmc-clkc.o
obj-$(CONFIG_COMMON_CLK_REGMAP_MESON) += clk-regmap.o
diff --git a/drivers/clk/meson/mmc-clkc.c b/drivers/clk/meson/mmc-clkc.c
new file mode 100644
index 000000000000..43b7a376746d
--- /dev/null
+++ b/drivers/clk/meson/mmc-clkc.c
@@ -0,0 +1,419 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
+/*
+ * Amlogic Meson MMC Sub Clock Controller Driver
+ *
+ * Copyright (c) 2018 Amlogic, inc.
+ * Author: Yixun Lan <yixun.lan@amlogic.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/of_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <dt-bindings/clock/amlogic,meson-mmc-clkc.h>
+
+#include "clkc.h"
+
+/* clock ID used by internal driver */
+#define CLKID_MMC_MUX 0
+#define CLKID_MMC_PHASE_CORE 2
+
+#define SD_EMMC_CLOCK 0
+#define CLK_DIV_MASK GENMASK(5, 0)
+#define CLK_SRC_MASK GENMASK(7, 6)
+#define CLK_CORE_PHASE_MASK GENMASK(9, 8)
+#define CLK_TX_PHASE_MASK GENMASK(11, 10)
+#define CLK_RX_PHASE_MASK GENMASK(13, 12)
+#define CLK_V2_TX_DELAY_MASK GENMASK(19, 16)
+#define CLK_V2_RX_DELAY_MASK GENMASK(23, 20)
+#define CLK_V2_ALWAYS_ON BIT(24)
+
+#define CLK_V3_TX_DELAY_MASK GENMASK(21, 16)
+#define CLK_V3_RX_DELAY_MASK GENMASK(27, 22)
+#define CLK_V3_ALWAYS_ON BIT(28)
+
+#define CLK_DELAY_STEP_PS 200
+#define CLK_PHASE_STEP 30
+#define CLK_PHASE_POINT_NUM (360 / CLK_PHASE_STEP)
+
+#define MUX_CLK_NUM_PARENTS 2
+#define MMC_MAX_CLKS 5
+
+struct clk_regmap_phase_data {
+ unsigned long phase_mask;
+ unsigned long delay_mask;
+ unsigned int delay_step_ps;
+};
+
+struct mmc_clkc_data {
+ struct clk_regmap_phase_data tx;
+ struct clk_regmap_phase_data rx;
+};
+
+struct mmc_clkc_info {
+ struct device *dev;
+ struct regmap *map;
+ struct mmc_clkc_data *data;
+};
+
+static inline struct clk_regmap_phase_data *
+clk_get_regmap_phase_data(struct clk_regmap *clk)
+{
+ return (struct clk_regmap_phase_data *)clk->data;
+}
+
+static struct clk_regmap_mux_data mmc_clkc_mux_data = {
+ .offset = SD_EMMC_CLOCK,
+ .mask = 0x3,
+ .shift = 6,
+ .flags = CLK_DIVIDER_ROUND_CLOSEST,
+};
+
+static struct clk_regmap_div_data mmc_clkc_div_data = {
+ .offset = SD_EMMC_CLOCK,
+ .shift = 0,
+ .width = 6,
+ .flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
+};
+
+static struct clk_regmap_phase_data mmc_clkc_core_phase = {
+ .phase_mask = CLK_CORE_PHASE_MASK,
+};
+
+static const struct mmc_clkc_data mmc_clkc_gx_data = {
+ {
+ .phase_mask = CLK_TX_PHASE_MASK,
+ .delay_mask = CLK_V2_TX_DELAY_MASK,
+ .delay_step_ps = CLK_DELAY_STEP_PS,
+ },
+ {
+ .phase_mask = CLK_RX_PHASE_MASK,
+ .delay_mask = CLK_V2_RX_DELAY_MASK,
+ .delay_step_ps = CLK_DELAY_STEP_PS,
+ },
+};
+
+static const struct mmc_clkc_data mmc_clkc_axg_data = {
+ {
+ .phase_mask = CLK_TX_PHASE_MASK,
+ .delay_mask = CLK_V3_TX_DELAY_MASK,
+ .delay_step_ps = CLK_DELAY_STEP_PS,
+ },
+ {
+ .phase_mask = CLK_RX_PHASE_MASK,
+ .delay_mask = CLK_V3_RX_DELAY_MASK,
+ .delay_step_ps = CLK_DELAY_STEP_PS,
+ },
+};
+
+static const struct of_device_id mmc_clkc_match_table[] = {
+ {
+ .compatible = "amlogic,meson-gx-mmc-clkc",
+ .data = &mmc_clkc_gx_data
+ },
+ {
+ .compatible = "amlogic,meson-axg-mmc-clkc",
+ .data = &mmc_clkc_axg_data
+ },
+ {}
+};
+MODULE_DEVICE_TABLE(of, mmc_clkc_match_table);
+
+static struct clk_regmap *mmc_clkc_register_mux(struct mmc_clkc_info *clkc)
+{
+ const char *parent_names[MUX_CLK_NUM_PARENTS];
+ struct device *dev = clkc->dev;
+ struct clk_init_data init;
+ struct clk_regmap *mux;
+ struct clk *clk;
+ char *mux_name;
+ int i, ret;
+
+ mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
+ char name[8];
+
+ snprintf(name, sizeof(name), "clkin%d", i);
+ clk = devm_clk_get(dev, name);
+ if (IS_ERR(clk)) {
+ if (clk != ERR_PTR(-EPROBE_DEFER))
+ dev_err(dev, "Missing clock %s\n", name);
+ return ERR_PTR((long)clk);
+ }
+
+ parent_names[i] = __clk_get_name(clk);
+ }
+
+ mux_name = kasprintf(GFP_KERNEL, "%s#mux", dev_name(dev));
+ if (!mux_name)
+ return ERR_PTR(-ENOMEM);
+
+ mux->map = clkc->map;
+ mux->data = &mmc_clkc_mux_data;
+
+ init.name = mux_name;
+ init.ops = &clk_regmap_mux_ops;
+ init.flags = CLK_SET_RATE_PARENT;
+ init.parent_names = parent_names;
+ init.num_parents = MUX_CLK_NUM_PARENTS;
+
+ mux->hw.init = &init;
+ ret = devm_clk_hw_register(dev, &mux->hw);
+ if (ret) {
+ dev_err(dev, "Mux clock registration failed\n");
+ mux = ERR_PTR(ret);
+ }
+
+ kfree(mux_name);
+ return mux;
+}
+
+static struct clk_regmap *mmc_clkc_register_div(struct mmc_clkc_info *clkc)
+{
+ const char *parent_names[MUX_CLK_NUM_PARENTS];
+ struct device *dev = clkc->dev;
+ struct clk_init_data init;
+ struct clk_regmap *div;
+ char *mux_name, *div_name;
+ int ret;
+
+ div = devm_kzalloc(dev, sizeof(*div), GFP_KERNEL);
+ if (!div)
+ return ERR_PTR(-ENOMEM);
+
+ mux_name = kasprintf(GFP_KERNEL, "%s#mux", dev_name(dev));
+ div_name = kasprintf(GFP_KERNEL, "%s#div", dev_name(dev));
+ if (!mux_name || !div_name) {
+ div = ERR_PTR(-ENOMEM);
+ goto err;
+ }
+
+ parent_names[0] = mux_name;
+ div->map = clkc->map;
+ div->data = &mmc_clkc_div_data;
+
+ init.name = div_name;
+ init.ops = &clk_regmap_divider_ops;
+ init.flags = CLK_SET_RATE_PARENT;
+ init.parent_names = parent_names;
+ init.num_parents = 1;
+
+ div->hw.init = &init;
+ ret = devm_clk_hw_register(dev, &div->hw);
+ if (ret) {
+ dev_err(dev, "Divider clock registration failed\n");
+ div = ERR_PTR(ret);
+ }
+
+err:
+ kfree(mux_name);
+ kfree(div_name);
+ return div;
+}
+
+static int clk_regmap_get_phase(struct clk_hw *hw)
+{
+ struct clk_regmap *clk = to_clk_regmap(hw);
+ struct clk_regmap_phase_data *ph = clk_get_regmap_phase_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_get_rate(hw->clk));
+ d = (val & ph->delay_mask) >> __ffs(ph->delay_mask);
+ degrees += d * ph->delay_step_ps * 360 / period_ps;
+ degrees %= 360;
+ }
+
+ return degrees;
+}
+
+static void clk_regmap_apply_phase_delay(struct clk_regmap *clk,
+ unsigned int phase,
+ unsigned int delay)
+{
+ struct clk_regmap_phase_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 clk_regmap_set_phase(struct clk_hw *hw, int degrees)
+{
+ struct clk_regmap *clk = to_clk_regmap(hw);
+ struct clk_regmap_phase_data *ph = clk_get_regmap_phase_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_get_rate(hw->clk));
+
+ /* 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));
+ }
+
+ clk_regmap_apply_phase_delay(clk, p, d);
+ return 0;
+}
+
+static const struct clk_ops clk_regmap_phase_ops = {
+ .get_phase = clk_regmap_get_phase,
+ .set_phase = clk_regmap_set_phase,
+};
+
+static struct clk_regmap *
+mmc_clkc_register_phase_clk(struct mmc_clkc_info *clkc,
+ char *name, char *parent_name, unsigned long flags,
+ struct clk_regmap_phase_data *phase_data)
+
+{
+ const char *parent_names[MUX_CLK_NUM_PARENTS];
+ struct device *dev = clkc->dev;
+ struct clk_init_data init;
+ struct clk_regmap *x;
+ char *clk_name, *core_name;
+ int ret;
+
+ /* create the mmc rx clock */
+ x = devm_kzalloc(dev, sizeof(*x), GFP_KERNEL);
+ if (!x)
+ return ERR_PTR(-ENOMEM);
+
+ clk_name = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), name);
+ core_name = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), parent_name);
+
+ if (!clk_name || !core_name) {
+ x = ERR_PTR(-ENOMEM);
+ goto err;
+ }
+ parent_names[0] = core_name;
+
+ init.name = clk_name;
+ init.ops = &clk_regmap_phase_ops;
+ init.flags = flags;
+ init.parent_names = parent_names;
+ init.num_parents = 1;
+
+ x->map = clkc->map;
+ x->data = phase_data;
+ x->hw.init = &init;
+
+ ret = devm_clk_hw_register(dev, &x->hw);
+ if (ret) {
+ dev_err(dev, "Core %s clock registration failed\n", name);
+ x = ERR_PTR(ret);
+ }
+err:
+ kfree(clk_name);
+ kfree(core_name);
+ return x;
+}
+
+static int mmc_clkc_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mmc_clkc_info *clkc;
+ struct clk_regmap *mux, *div, *core, *rx, *tx;
+ struct clk_hw_onecell_data *onecell_data;
+
+ clkc = devm_kzalloc(dev, sizeof(*clkc), GFP_KERNEL);
+ if (!clkc)
+ return -ENOMEM;
+
+ clkc->data = (struct mmc_clkc_data *)of_device_get_match_data(dev);
+ if (!clkc->data)
+ return -EINVAL;
+
+ clkc->dev = dev;
+ clkc->map = syscon_node_to_regmap(dev->of_node);
+
+ if (IS_ERR(clkc->map)) {
+ dev_err(dev, "could not find mmc clock controller\n");
+ return PTR_ERR(clkc->map);
+ }
+
+ onecell_data = devm_kzalloc(dev, sizeof(*onecell_data) +
+ sizeof(*onecell_data->hws) * MMC_MAX_CLKS,
+ GFP_KERNEL);
+ if (!onecell_data)
+ return -ENOMEM;
+
+ mux = mmc_clkc_register_mux(clkc);
+ if (IS_ERR(mux))
+ return PTR_ERR(mux);
+
+ div = mmc_clkc_register_div(clkc);
+ if (IS_ERR(div))
+ return PTR_ERR(div);
+
+ core = mmc_clkc_register_phase_clk(clkc, "core", "div",
+ CLK_SET_RATE_PARENT,
+ &mmc_clkc_core_phase);
+ if (IS_ERR(core))
+ return PTR_ERR(core);
+
+ rx = mmc_clkc_register_phase_clk(clkc, "rx", "core", 0,
+ &clkc->data->rx);
+ if (IS_ERR(rx))
+ return PTR_ERR(rx);
+
+ tx = mmc_clkc_register_phase_clk(clkc, "tx", "core", 0,
+ &clkc->data->tx);
+ if (IS_ERR(tx))
+ return PTR_ERR(tx);
+
+ onecell_data->hws[CLKID_MMC_MUX] = &mux->hw,
+ onecell_data->hws[CLKID_MMC_DIV] = &div->hw,
+ onecell_data->hws[CLKID_MMC_PHASE_CORE] = &core->hw,
+ onecell_data->hws[CLKID_MMC_PHASE_RX] = &rx->hw,
+ onecell_data->hws[CLKID_MMC_PHASE_TX] = &tx->hw,
+ onecell_data->num = MMC_MAX_CLKS;
+
+ return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
+ onecell_data);
+}
+
+static struct platform_driver mmc_clkc_driver = {
+ .probe = mmc_clkc_probe,
+ .driver = {
+ .name = "meson-mmc-clkc",
+ .of_match_table = of_match_ptr(mmc_clkc_match_table),
+ },
+};
+
+module_platform_driver(mmc_clkc_driver);
--
2.18.0
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