clk: at91: clk-programmable: add driver compatible with ccf

Add clk-programmable driver compatible with common clock framework.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>

3 files changed, 226 insertions, 1 deletions

diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
index 9c38bda..8951052 100644
--- a/drivers/clk/at91/Makefile
+++ b/drivers/clk/at91/Makefile
@@ -3,7 +3,7 @@
 #
 
 ifdef CONFIG_CLK_CCF
-obj-y += pmc.o sckc.o clk-main.o clk-master.o
+obj-y += pmc.o sckc.o clk-main.o clk-master.o clk-programmable.o
 obj-$(CONFIG_AT91_UTMI)		+= clk-utmi.o
 obj-$(CONFIG_AT91_SAM9X60_PLL)	+= clk-sam9x60-pll.o
 else
diff --git a/drivers/clk/at91/clk-programmable.c b/drivers/clk/at91/clk-programmable.c
new file mode 100644
index 0000000..868de4b
--- /dev/null
+++ b/drivers/clk/at91/clk-programmable.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Programmable clock support for AT91 architectures.
+ *
+ * Copyright (C) 2020 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Claudiu Beznea <claudiu.beznea@microchip.com>
+ *
+ * Based on drivers/clk/at91/clk-programmable.c from Linux.
+ */
+#include <common.h>
+#include <clk-uclass.h>
+#include <dm.h>
+#include <linux/clk-provider.h>
+#include <linux/clk/at91_pmc.h>
+
+#include "pmc.h"
+
+#define UBOOT_DM_CLK_AT91_PROG		"at91-prog-clk"
+
+#define PROG_ID_MAX		7
+
+#define PROG_STATUS_MASK(id)	(1 << ((id) + 8))
+#define PROG_PRES(_l, _p)	(((_p) >> (_l)->pres_shift) & (_l)->pres_mask)
+#define PROG_MAX_RM9200_CSS	3
+
+struct clk_programmable {
+	void __iomem *base;
+	const u32 *clk_mux_table;
+	const u32 *mux_table;
+	const struct clk_programmable_layout *layout;
+	u32 num_parents;
+	struct clk clk;
+	u8 id;
+};
+
+#define to_clk_programmable(_c) container_of(_c, struct clk_programmable, clk)
+
+static ulong clk_programmable_get_rate(struct clk *clk)
+{
+	struct clk_programmable *prog = to_clk_programmable(clk);
+	const struct clk_programmable_layout *layout = prog->layout;
+	ulong rate, parent_rate = clk_get_parent_rate(clk);
+	unsigned int pckr;
+
+	pmc_read(prog->base, AT91_PMC_PCKR(prog->id), &pckr);
+
+	if (layout->is_pres_direct)
+		rate = parent_rate / (PROG_PRES(layout, pckr) + 1);
+	else
+		rate = parent_rate >> PROG_PRES(layout, pckr);
+
+	return rate;
+}
+
+static int clk_programmable_set_parent(struct clk *clk, struct clk *parent)
+{
+	struct clk_programmable *prog = to_clk_programmable(clk);
+	const struct clk_programmable_layout *layout = prog->layout;
+	unsigned int mask = layout->css_mask;
+	int index;
+
+	index = at91_clk_mux_val_to_index(prog->clk_mux_table,
+					  prog->num_parents, parent->id);
+	if (index < 0)
+		return index;
+
+	index = at91_clk_mux_index_to_val(prog->mux_table, prog->num_parents,
+					  index);
+	if (index < 0)
+		return index;
+
+	if (layout->have_slck_mck)
+		mask |= AT91_PMC_CSSMCK_MCK;
+
+	if (index > layout->css_mask) {
+		if (index > PROG_MAX_RM9200_CSS && !layout->have_slck_mck)
+			return -EINVAL;
+
+		index |= AT91_PMC_CSSMCK_MCK;
+	}
+
+	pmc_update_bits(prog->base, AT91_PMC_PCKR(prog->id), mask, index);
+
+	return 0;
+}
+
+static ulong clk_programmable_set_rate(struct clk *clk, ulong rate)
+{
+	struct clk_programmable *prog = to_clk_programmable(clk);
+	const struct clk_programmable_layout *layout = prog->layout;
+	ulong parent_rate = clk_get_parent_rate(clk);
+	ulong div = parent_rate / rate;
+	int shift = 0;
+
+	if (!parent_rate || !div)
+		return -EINVAL;
+
+	if (layout->is_pres_direct) {
+		shift = div - 1;
+
+		if (shift > layout->pres_mask)
+			return -EINVAL;
+	} else {
+		shift = fls(div) - 1;
+
+		if (div != (1 << shift))
+			return -EINVAL;
+
+		if (shift >= layout->pres_mask)
+			return -EINVAL;
+	}
+
+	pmc_update_bits(prog->base, AT91_PMC_PCKR(prog->id),
+			layout->pres_mask << layout->pres_shift,
+			shift << layout->pres_shift);
+
+	if (layout->is_pres_direct)
+		return (parent_rate / shift + 1);
+
+	return parent_rate >> shift;
+}
+
+static const struct clk_ops programmable_ops = {
+	.get_rate = clk_programmable_get_rate,
+	.set_parent = clk_programmable_set_parent,
+	.set_rate = clk_programmable_set_rate,
+};
+
+struct clk *at91_clk_register_programmable(void __iomem *base, const char *name,
+			const char *const *parent_names, u8 num_parents, u8 id,
+			const struct clk_programmable_layout *layout,
+			const u32 *clk_mux_table, const u32 *mux_table)
+{
+	struct clk_programmable *prog;
+	struct clk *clk;
+	u32 val, tmp;
+	int ret;
+
+	if (!base || !name || !parent_names || !num_parents ||
+	    !layout || !clk_mux_table || !mux_table || id > PROG_ID_MAX)
+		return ERR_PTR(-EINVAL);
+
+	prog = kzalloc(sizeof(*prog), GFP_KERNEL);
+	if (!prog)
+		return ERR_PTR(-ENOMEM);
+
+	prog->id = id;
+	prog->layout = layout;
+	prog->base = base;
+	prog->clk_mux_table = clk_mux_table;
+	prog->mux_table = mux_table;
+	prog->num_parents = num_parents;
+
+	pmc_read(prog->base, AT91_PMC_PCKR(prog->id), &tmp);
+	val = tmp & prog->layout->css_mask;
+	if (layout->have_slck_mck && (tmp & AT91_PMC_CSSMCK_MCK) && !val)
+		ret = PROG_MAX_RM9200_CSS + 1;
+	else
+		ret = at91_clk_mux_val_to_index(prog->mux_table,
+						prog->num_parents, val);
+	if (ret < 0) {
+		kfree(prog);
+		return ERR_PTR(ret);
+	}
+
+	clk = &prog->clk;
+	clk->flags = CLK_GET_RATE_NOCACHE;
+	ret = clk_register(clk, UBOOT_DM_CLK_AT91_PROG, name,
+			   parent_names[ret]);
+	if (ret) {
+		kfree(prog);
+		clk = ERR_PTR(ret);
+	}
+
+	return clk;
+}
+
+U_BOOT_DRIVER(at91_prog_clk) = {
+	.name = UBOOT_DM_CLK_AT91_PROG,
+	.id = UCLASS_CLK,
+	.ops = &programmable_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};
+
+const struct clk_programmable_layout at91rm9200_programmable_layout = {
+	.pres_mask = 0x7,
+	.pres_shift = 2,
+	.css_mask = 0x3,
+	.have_slck_mck = 0,
+	.is_pres_direct = 0,
+};
+
+const struct clk_programmable_layout at91sam9g45_programmable_layout = {
+	.pres_mask = 0x7,
+	.pres_shift = 2,
+	.css_mask = 0x3,
+	.have_slck_mck = 1,
+	.is_pres_direct = 0,
+};
+
+const struct clk_programmable_layout at91sam9x5_programmable_layout = {
+	.pres_mask = 0x7,
+	.pres_shift = 4,
+	.css_mask = 0x7,
+	.have_slck_mck = 0,
+	.is_pres_direct = 0,
+};
diff --git a/drivers/clk/at91/pmc.h b/drivers/clk/at91/pmc.h
index d34005f..a443b65 100644
--- a/drivers/clk/at91/pmc.h
+++ b/drivers/clk/at91/pmc.h
@@ -55,6 +55,18 @@ struct clk_pll_layout {
 	u8 endiv_shift;
 };
 
+struct clk_programmable_layout {
+	u8 pres_mask;
+	u8 pres_shift;
+	u8 css_mask;
+	u8 have_slck_mck;
+	u8 is_pres_direct;
+};
+
+extern const struct clk_programmable_layout at91rm9200_programmable_layout;
+extern const struct clk_programmable_layout at91sam9g45_programmable_layout;
+extern const struct clk_programmable_layout at91sam9x5_programmable_layout;
+
 struct clk *at91_clk_main_rc(void __iomem *reg, const char *name,
 			const char *parent_name);
 struct clk *at91_clk_main_osc(void __iomem *reg, const char *name,
@@ -91,6 +103,11 @@ at91_clk_register_utmi(void __iomem *base, struct udevice *dev,
 struct clk *
 at91_clk_sama7g5_register_utmi(void __iomem *base, const char *name,
 			const char *parent_name);
+struct clk *
+at91_clk_register_programmable(void __iomem *base, const char *name,
+			const char * const *parent_names, u8 num_parents, u8 id,
+			const struct clk_programmable_layout *layout,
+			const u32 *clk_mux_table, const u32 *mux_table);
 
 int at91_clk_mux_val_to_index(const u32 *table, u32 num_parents, u32 val);
 int at91_clk_mux_index_to_val(const u32 *table, u32 num_parents, u32 index);