Date:	Fri,  9 Oct 2015 13:35:21 +0100
From:	Mans Rullgard <mans@...sr.com>
To:	Michael Turquette <mturquette@...libre.com>,
	Stephen Boyd <sboyd@...eaurora.org>,
	linux-kernel@...r.kernel.org, linux-clk@...r.kernel.org
Subject: [PATCH] clk: add support for Sigma Designs SMP86xx/87xx clocks

This adds support for most of the clocks in the Sigma Designs
SMP86xx (tango3) and SMP87xx (tango4) chips.

Signed-off-by: Mans Rullgard <mans@...sr.com>
---
I'm sending this now to avoid the maintainers wasting more time reviewing
the woefully incomplete patch that was posted earlier this week.  Unlike
that patch, this driver accurately represents the various PLLs, muxes,
and dividers, allowing it to work correctly across all the chip variants.
That said, this patch still needs some work, which is why I have not posted
it sooner.  Obvious shortcomings off the top of my head:
- DT binding documentation is missing
- Most clocks are mostly read-only
- Some control register fields are ignored (lack of documentation)
---
 drivers/clk/Kconfig      |   7 +
 drivers/clk/Makefile     |   1 +
 drivers/clk/clk-tangox.c | 656 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 664 insertions(+)
 create mode 100644 drivers/clk/clk-tangox.c

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 42f7120..c876142 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -167,6 +167,13 @@ config COMMON_CLK_CDCE706
 	---help---
 	  This driver supports TI CDCE706 programmable 3-PLL clock synthesizer.
 
+config COMMON_CLK_TANGOX
+	bool "Clock driver for Sigma Designs SMP86xx/SMP87xx SOCs"
+	depends on OF
+	---help---
+	  This driver supports the Sigma Designs SMP86xx and SMP87xx clock
+	  tree.
+
 source "drivers/clk/bcm/Kconfig"
 source "drivers/clk/hisilicon/Kconfig"
 source "drivers/clk/qcom/Kconfig"
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index d08b3e5..0b2c3d6 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_COMMON_CLK_SI5351)		+= clk-si5351.o
 obj-$(CONFIG_COMMON_CLK_SI570)		+= clk-si570.o
 obj-$(CONFIG_COMMON_CLK_CDCE925)	+= clk-cdce925.o
 obj-$(CONFIG_ARCH_STM32)		+= clk-stm32f4.o
+obj-$(CONFIG_COMMON_CLK_TANGOX)		+= clk-tangox.o
 obj-$(CONFIG_CLK_TWL6040)		+= clk-twl6040.o
 obj-$(CONFIG_ARCH_U300)			+= clk-u300.o
 obj-$(CONFIG_ARCH_VT8500)		+= clk-vt8500.o
diff --git a/drivers/clk/clk-tangox.c b/drivers/clk/clk-tangox.c
new file mode 100644
index 0000000..3a18a93
--- /dev/null
+++ b/drivers/clk/clk-tangox.c
@@ -0,0 +1,656 @@
+/*
+ * Copyright (C) 2014 Mans Rullgard <mans@...sr.com>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+#include <asm/io.h>
+
+struct tangox_pll_clk {
+	struct clk_hw	hw;
+	void __iomem	*reg;
+	int		n_mask;
+	int		m_mask;
+	int		k_shift;
+	int		k_mask;
+	int		step;
+	spinlock_t	lock;
+	struct clk	*clk[3];
+	struct clk_onecell_data clk_data;
+	struct clk_mux	mux;
+};
+
+#define to_pll_clk(_hw) container_of(_hw, struct tangox_pll_clk, hw)
+
+static unsigned long tangox_pll_recalc(struct clk_hw *hw, unsigned long prate)
+{
+	struct tangox_pll_clk *pc = to_pll_clk(hw);
+	unsigned int pll;
+	int m, n, k;
+
+	pll = readl(pc->reg);
+
+	n = pll & pc->n_mask;
+	m = (pll >> 16) & pc->m_mask;
+	k = (pll >> pc->k_shift) & pc->k_mask;
+
+	n += pc->step;
+	m += pc->step;
+
+	return prate / m * n / (1 << k);
+}
+
+static struct clk_ops tangox_pll_ops = {
+	.recalc_rate	= tangox_pll_recalc,
+};
+
+static void __init tangox_clk_pll_setup(struct device_node *node)
+{
+	struct tangox_pll_clk *pc;
+	struct clk_mux *m;
+	const char *names[3];
+	const char **pnames = NULL;
+	int noutputs;
+	int nparents;
+	int table_len;
+	u32 n_bits;
+	u32 m_bits;
+	u32 k_bits[2];
+	u32 mn_bias;
+	int i;
+
+	noutputs = of_property_read_string_array(node, "clock-output-names",
+						 names, 3);
+
+	if (noutputs != 1 && noutputs != 3)
+		return;
+
+	nparents = of_clk_get_parent_count(node);
+	if (nparents <= 0)
+		return;
+
+	table_len = of_property_count_u32_elems(node, "sigma,mux-table");
+	if (table_len > 0 && table_len != nparents)
+		return;
+
+	pc = kzalloc(sizeof(*pc), GFP_KERNEL);
+	if (!pc)
+		return;
+
+	of_property_read_u32(node, "sigma,pll-n-bits", &n_bits);
+	of_property_read_u32(node, "sigma,pll-m-bits", &m_bits);
+	of_property_read_u32_array(node, "sigma,pll-k-bits", k_bits, 2);
+	of_property_read_u32(node, "sigma,pll-mn-bias", &mn_bias);
+
+	pc->reg = of_iomap(node, 0);
+	pc->n_mask = (1 << n_bits) - 1;
+	pc->m_mask = (1 << m_bits) - 1;
+	pc->k_shift = k_bits[1];
+	pc->k_mask = (1 << k_bits[0]) - 1;
+	pc->step = mn_bias;
+	spin_lock_init(&pc->lock);
+	pc->clk_data.clk_num = noutputs;
+	pc->clk_data.clks = pc->clk;
+
+	m = &pc->mux;
+	m->reg = pc->reg;
+	m->mask = 7;
+	m->shift = 24;
+	m->lock = &pc->lock;
+
+	pnames = kzalloc(nparents * sizeof(*pnames), GFP_KERNEL);
+	if (!pnames)
+		goto err;
+
+	for (i = 0; i < nparents; i++)
+		pnames[i] = of_clk_get_parent_name(node, i);
+
+	if (table_len > 0) {
+		m->table = kzalloc(table_len * sizeof(*m->table), GFP_KERNEL);
+		if (!m->table)
+			goto err;
+
+		of_property_read_u32_array(node, "sigma,mux-table",
+					   m->table, table_len);
+	}
+
+	pc->clk[0] = clk_register_composite(NULL, names[0], pnames, nparents,
+					    &pc->mux.hw, &clk_mux_ops,
+					    &pc->hw, &tangox_pll_ops,
+					    NULL, NULL, 0);
+	if (IS_ERR(pc->clk[0]))
+		goto err;
+
+	if (noutputs > 1) {
+		pc->clk[1] = clk_register_divider(NULL, names[1], names[0], 0,
+						  pc->reg + 4, 0, 4,
+						  CLK_DIVIDER_ONE_BASED,
+						  &pc->lock);
+
+		pc->clk[2] = clk_register_divider(NULL, names[2], names[0], 0,
+						  pc->reg + 4, 8, 4,
+						  CLK_DIVIDER_ONE_BASED,
+						  &pc->lock);
+	}
+
+	of_clk_add_provider(node, of_clk_src_onecell_get, &pc->clk_data);
+
+	kfree(pnames);
+	return;
+
+err:
+	kfree(pnames);
+	kfree(pc->mux.table);
+	kfree(pc);
+}
+CLK_OF_DECLARE(tangox_pll, "sigma,smp8640-pll-clk", tangox_clk_pll_setup);
+
+struct tangox_premux_clk {
+	struct clk *clks[2];
+	struct clk_onecell_data clk_data;
+	spinlock_t lock;
+};
+
+static void __init tangox_clk_premux_setup(struct device_node *node)
+{
+	struct tangox_premux_clk *mc;
+	const char *names[2];
+	const char **pnames = NULL;
+	void __iomem *reg;
+	u32 *sys_table = NULL;
+	u32 *cd_table = NULL;
+	int nparents;
+	int nsys;
+	int ncd;
+	int i;
+
+	nparents = of_clk_get_parent_count(node);
+	if (nparents <= 0)
+		return;
+
+	nsys = of_property_count_u32_elems(node, "sigma,sys-table");
+	ncd = of_property_count_u32_elems(node, "sigma,cd-table");
+
+	if (nsys + ncd != nparents)
+		return;
+
+	mc = kzalloc(sizeof(*mc), GFP_KERNEL);
+	if (!mc)
+		return;
+
+	pnames = kzalloc(nparents * sizeof(*pnames), GFP_KERNEL);
+	if (!pnames)
+		goto err;
+
+	for (i = 0; i < nparents; i++)
+		pnames[i] = of_clk_get_parent_name(node, i);
+
+	if (of_property_read_string_array(node, "clock-output-names",
+					  names, 2) < 2)
+		goto err;
+
+	sys_table = kzalloc(nsys * sizeof(*sys_table), GFP_KERNEL);
+	if (!sys_table)
+		goto err;
+
+	of_property_read_u32_array(node, "sigma,sys-table", sys_table, nsys);
+
+	cd_table = kzalloc(ncd * sizeof(*cd_table), GFP_KERNEL);
+	if (!cd_table)
+		goto err;
+
+	of_property_read_u32_array(node, "sigma,cd-table", cd_table, ncd);
+
+	mc->clk_data.clks = mc->clks;
+	mc->clk_data.clk_num = 2;
+	spin_lock_init(&mc->lock);
+
+	reg = of_iomap(node, 0);
+	if (!reg)
+		goto err;
+
+	mc->clks[0] = clk_register_mux_table(NULL, names[0], pnames, nsys,
+					     0, reg, 0, 3, 0, sys_table,
+					     &mc->lock);
+
+	mc->clks[1] = clk_register_mux_table(NULL, names[1], pnames + nsys, ncd,
+					     0, reg, 8, 7, 0, cd_table,
+					     &mc->lock);
+
+	of_clk_add_provider(node, of_clk_src_onecell_get, &mc->clk_data);
+
+	kfree(pnames);
+	return;
+
+err:
+	kfree(sys_table);
+	kfree(cd_table);
+	kfree(pnames);
+	kfree(mc);
+}
+CLK_OF_DECLARE(tangox_premux, "sigma,smp8640-premux-clk",
+	       tangox_clk_premux_setup);
+
+static void __init tangox_clk_sysmux_setup(struct device_node *node)
+{
+	struct clk_onecell_data *clk_data;
+	struct clk_divider *div = NULL;
+	struct clk_mux *mux = NULL;
+	struct clk_div_table *divtab;
+	const char *parents[2];
+	const char *name;
+	void __iomem *reg;
+	int nclks;
+	int ndivs;
+	struct clk *c;
+	int i, j;
+
+	reg = of_iomap(node, 0);
+
+	nclks = of_property_count_strings(node, "clock-output-names");
+	ndivs = of_property_count_u32_elems(node, "sigma,divisors") / nclks;
+
+	parents[0] = of_clk_get_parent_name(node, 0);
+	parents[1] = of_clk_get_parent_name(node, 1);
+
+	clk_data = kzalloc(sizeof(*clk_data) + nclks * sizeof(*clk_data->clks),
+			   GFP_KERNEL);
+	if (!clk_data)
+		return;
+
+	clk_data->clks = (struct clk **)(clk_data + 1);
+	clk_data->clk_num = nclks;
+
+	for (i = 0; i < nclks; i++) {
+		divtab = kzalloc((ndivs + 1) * sizeof(*divtab), GFP_KERNEL);
+		if (!divtab)
+			return;
+
+		for (j = 0; j < ndivs; j++) {
+			divtab[j].val = j;
+			of_property_read_u32_index(node, "sigma,divisors",
+						   i * ndivs + j,
+						   &divtab[j].div);
+		}
+
+		mux = kzalloc(sizeof(*mux), GFP_KERNEL);
+		div = kzalloc(sizeof(*div), GFP_KERNEL);
+
+		if (!mux || !div)
+			return;
+
+		mux->reg = reg;
+		mux->mask = 1;
+		mux->shift = 0;
+
+		div->reg = reg;
+		div->shift = 8;
+		div->width = 4;
+		div->flags = CLK_DIVIDER_READ_ONLY;
+		div->table = divtab;
+
+		of_property_read_string_index(node, "clock-output-names", i,
+					      &name);
+
+		c = clk_register_composite(NULL, name, parents, 2,
+					   &mux->hw, &clk_mux_ro_ops,
+					   &div->hw, &clk_divider_ops,
+					   NULL, NULL, 0);
+
+		if (IS_ERR(c)) {
+			pr_err("%s: error creating clock %s\n",
+			       node->name, name);
+			return;
+		}
+
+		clk_register_clkdev(c, name, NULL);
+		clk_data->clks[i] = c;
+	}
+
+	of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
+}
+CLK_OF_DECLARE(tangox_sysmux, "sigma,smp8640-sysmux-clk",
+	       tangox_clk_sysmux_setup);
+
+struct tangox_cleandiv_clk {
+	struct clk_hw hw;
+	void __iomem *reg;
+	struct clk *clk[3];
+	struct clk_onecell_data clk_data;
+};
+
+#define to_tangox_cleandiv_clk(_hw) \
+	container_of(_hw, struct tangox_cleandiv_clk, hw)
+
+static int tangox_clk_cleandiv_enable(struct clk_hw *hw)
+{
+	struct tangox_cleandiv_clk *cd = to_tangox_cleandiv_clk(hw);
+	u32 ctrl;
+
+	ctrl = readl(cd->reg + 4);
+	writel(ctrl & ~1, cd->reg + 4);
+
+	return 0;
+}
+
+static void tangox_clk_cleandiv_disable(struct clk_hw *hw)
+{
+	struct tangox_cleandiv_clk *cd = to_tangox_cleandiv_clk(hw);
+	u32 ctrl;
+
+	ctrl = readl(cd->reg + 4);
+	writel(ctrl | 1, cd->reg + 4);
+}
+
+static int tangox_clk_cleandiv_is_enabled(struct clk_hw *hw)
+{
+	struct tangox_cleandiv_clk *cd = to_tangox_cleandiv_clk(hw);
+	u32 ctrl;
+
+	ctrl = readl(cd->reg + 4);
+
+	return !(ctrl & 1);
+}
+
+static unsigned long tangox_clk_cleandiv_recalc(struct clk_hw *hw,
+					  unsigned long prate)
+{
+	struct tangox_cleandiv_clk *cd = to_tangox_cleandiv_clk(hw);
+	u64 rate;
+	u32 div;
+
+	div = readl(cd->reg);
+
+	rate = (u64)prate << 27;
+	do_div(rate, (2 << 27) + div);
+
+	return rate;
+}
+
+static const struct clk_ops tangox_cleandiv_clk_ops = {
+	.enable		= tangox_clk_cleandiv_enable,
+	.disable	= tangox_clk_cleandiv_disable,
+	.is_enabled	= tangox_clk_cleandiv_is_enabled,
+	.recalc_rate	= tangox_clk_cleandiv_recalc,
+};
+
+static void __init tangox_clk_cleandiv_setup(struct device_node *node)
+{
+	struct tangox_cleandiv_clk *cd;
+	struct clk_init_data id;
+	const char *names[3];
+	const char *pname;
+
+	if (of_property_read_string_array(node, "clock-output-names",
+					  names, 3) < 3)
+		return;
+
+	pname = of_clk_get_parent_name(node, 0);
+
+	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
+	if (!cd)
+		return;
+
+	id.name = names[0];
+	id.ops = &tangox_cleandiv_clk_ops;
+	id.parent_names = &pname;
+	id.num_parents = 1;
+	id.flags = 0;
+
+	cd->hw.init = &id;
+	cd->reg = of_iomap(node, 0);
+	cd->clk_data.clks = cd->clk;
+	cd->clk_data.clk_num = 3;
+
+	cd->clk[0] = clk_register(NULL, &cd->hw);
+	cd->clk[1] = clk_register_fixed_factor(NULL, names[1], names[0],
+					       0, 1, 2);
+	cd->clk[2] = clk_register_fixed_factor(NULL, names[2], names[0],
+					       0, 1, 4);
+
+	of_clk_add_provider(node, of_clk_src_onecell_get, &cd->clk_data);
+}
+CLK_OF_DECLARE(tangox_cd, "sigma,smp8640-cleandiv-clk",
+	       tangox_clk_cleandiv_setup);
+
+struct tangox_mux_clk {
+	struct clk_hw hw;
+	void __iomem *reg;
+	u32 shift;
+	u32 mask;
+	u32 *table;
+};
+
+#define to_tangox_mux_clk(_hw) container_of(_hw, struct tangox_mux_clk, hw)
+
+static u8 tangox_clk_mux_get_parent(struct clk_hw *hw)
+{
+	struct tangox_mux_clk *m = to_tangox_mux_clk(hw);
+	int nparents;
+	u32 v;
+	int i;
+
+	v = readl(m->reg) >> m->shift & m->mask;
+
+	if (m->table) {
+		nparents = clk_hw_get_num_parents(hw);
+
+		for (i = 0; i < nparents; i++)
+			if (m->table[i] == v)
+				return i;
+
+		return -EINVAL;
+	}
+
+	return v - 1;
+}
+
+static int tangox_clk_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct tangox_mux_clk *m = to_tangox_mux_clk(hw);
+
+	if (m->table)
+		index = m->table[index];
+	else
+		index++;
+
+	if (!index)
+		return -EINVAL;
+
+	writel(index << m->shift, m->reg);
+
+	return 0;
+}
+
+static const struct clk_ops tangox_mux_clk_ops = {
+	.get_parent	= tangox_clk_mux_get_parent,
+	.set_parent	= tangox_clk_mux_set_parent,
+};
+
+static void __init tangox_clk_mux_setup(struct device_node *node)
+{
+	struct tangox_mux_clk *m;
+	struct clk_init_data id;
+	struct clk *clk;
+	const char **pnames = NULL;
+	int nparents;
+	int table_len;
+	u32 bits[2];
+	int i;
+
+	nparents = of_clk_get_parent_count(node);
+	if (nparents <= 0)
+		return;
+
+	table_len = of_property_count_u32_elems(node, "sigma,mux-table");
+	if (table_len > 0 && table_len != nparents)
+		return;
+
+	m = kzalloc(sizeof(*m), GFP_KERNEL);
+	if (!m)
+		return;
+
+	pnames = kzalloc(nparents * sizeof(*pnames), GFP_KERNEL);
+	if (!pnames)
+		goto err;
+
+	for (i = 0; i < nparents; i++)
+		pnames[i] = of_clk_get_parent_name(node, i);
+
+	if (table_len > 0) {
+		m->table = kzalloc(table_len * sizeof(*m->table), GFP_KERNEL);
+		if (!m->table)
+			goto err;
+
+		of_property_read_u32_array(node, "sigma,mux-table",
+					   m->table, table_len);
+	}
+
+	if (of_property_read_u32_array(node, "sigma,bits", bits, 2))
+		goto err;
+
+	if (of_property_read_string(node, "clock-output-names", &id.name))
+		id.name = node->name;
+	id.ops = &tangox_mux_clk_ops;
+	id.parent_names = pnames;
+	id.num_parents = nparents;
+	id.flags = 0;
+
+	m->hw.init = &id;
+	m->reg = of_iomap(node, 0);
+	m->shift = bits[0];
+	m->mask = (1 << bits[1]) - 1;
+
+	clk = clk_register(NULL, &m->hw);
+	if (IS_ERR(clk))
+		goto err;
+
+	of_clk_add_provider(node, of_clk_src_simple_get, clk);
+
+	kfree(pnames);
+	return;
+
+err:
+	kfree(pnames);
+	kfree(m->table);
+	kfree(m);
+}
+CLK_OF_DECLARE(tangox_mux, "sigma,smp8640-mux-clk", tangox_clk_mux_setup);
+
+struct tangox_div_clk {
+	struct clk_hw hw;
+	void __iomem *reg;
+};
+
+#define to_tangox_div_clk(_hw) container_of(_hw, struct tangox_div_clk, hw)
+
+static u8 tangox_clk_div_get_parent(struct clk_hw *hw)
+{
+	struct tangox_div_clk *dc = to_tangox_div_clk(hw);
+	u32 ctrl;
+
+	ctrl = readl(dc->reg);
+
+	return ctrl >> 23 & 1;
+}
+
+static int tangox_clk_div_set_parent(struct clk_hw *hw, u8 parent)
+{
+	struct tangox_div_clk *dc = to_tangox_div_clk(hw);
+	u32 ctrl;
+
+	ctrl = readl(dc->reg);
+	ctrl &= ~(1 << 23);
+	ctrl |= parent << 23;
+	writel(ctrl, dc->reg);
+
+	return 0;
+}
+
+static unsigned long tangox_clk_div_recalc(struct clk_hw *hw,
+					   unsigned long prate)
+{
+	struct tangox_div_clk *dc = to_tangox_div_clk(hw);
+	u32 div, scale;
+	u32 i, f;
+	u32 ctrl;
+	u64 rate;
+
+	ctrl = readl(dc->reg);
+
+	if (ctrl & (1 << 23))
+		return prate;
+
+	f = ctrl & 0xf;
+	i = ctrl >> 8 & 0xff;
+
+	if (i == 0)
+		return 0;
+
+	if (i == 1)
+		scale = 32 - f;
+	else
+		scale = 16;
+
+	div = i * scale + f;
+	rate = (u64)prate * scale;
+	do_div(rate, div);
+
+	return rate;
+}
+
+static const struct clk_ops tangox_div_clk_ops = {
+	.get_parent	= tangox_clk_div_get_parent,
+	.set_parent	= tangox_clk_div_set_parent,
+	.recalc_rate	= tangox_clk_div_recalc,
+};
+
+static void __init tangox_clk_div_setup(struct device_node *node)
+{
+	struct tangox_div_clk *dc;
+	struct clk_init_data id;
+	struct clk *clk;
+	const char *pnames[2];
+	int i;
+
+	if (of_clk_get_parent_count(node) != 2)
+		return;
+
+	dc = kzalloc(sizeof(*dc), GFP_KERNEL);
+	if (!dc)
+		return;
+
+	for (i = 0; i < 2; i++)
+		pnames[i] = of_clk_get_parent_name(node, i);
+
+	if (of_property_read_string(node, "clock-output-names", &id.name))
+		id.name = node->name;
+	id.ops = &tangox_div_clk_ops;
+	id.parent_names = pnames;
+	id.num_parents = 2;
+	id.flags = 0;
+
+	dc->hw.init = &id;
+	dc->reg = of_iomap(node, 0);
+
+	clk = clk_register(NULL, &dc->hw);
+	if (IS_ERR(clk))
+		goto err;
+
+	of_clk_add_provider(node, of_clk_src_simple_get, clk);
+	return;
+
+err:
+	kfree(dc);
+}
+CLK_OF_DECLARE(tangox_div, "sigma,smp8750-div-clk", tangox_clk_div_setup);
-- 
2.5.3

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