[PATCHv2 1/5] clk: mvebu: support for 98DX3236 SoC

From: Chris Packham
Date: Wed Jan 04 2017 - 22:38:50 EST


The 98DX3236, 98DX3336, 98DX4521 and variants have a different TCLK from
the Armada XP (200MHz vs 250MHz). The CPU core clock is fixed at 800MHz.

The clock gating options are a subset of those on the Armada XP.

The core clock divider is different to the Armada XP also.

Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
---
Changes in v2:
- Update devicetree binding documentation for new compatible string

.../devicetree/bindings/clock/mvebu-cpu-clock.txt | 1 +
drivers/clk/mvebu/Makefile | 2 +-
drivers/clk/mvebu/armada-xp.c | 42 +++++
drivers/clk/mvebu/clk-cpu.c | 33 +++-
drivers/clk/mvebu/mv98dx3236-corediv.c | 207 +++++++++++++++++++++
5 files changed, 281 insertions(+), 4 deletions(-)
create mode 100644 drivers/clk/mvebu/mv98dx3236-corediv.c

diff --git a/Documentation/devicetree/bindings/clock/mvebu-cpu-clock.txt b/Documentation/devicetree/bindings/clock/mvebu-cpu-clock.txt
index 99c214660bdc..7f28506eaee7 100644
--- a/Documentation/devicetree/bindings/clock/mvebu-cpu-clock.txt
+++ b/Documentation/devicetree/bindings/clock/mvebu-cpu-clock.txt
@@ -3,6 +3,7 @@ Device Tree Clock bindings for cpu clock of Marvell EBU platforms
Required properties:
- compatible : shall be one of the following:
"marvell,armada-xp-cpu-clock" - cpu clocks for Armada XP
+ "marvell,mv98dx3236-cpu-clock" - cpu clocks for 98DX3236 SoC
- reg : Address and length of the clock complex register set, followed
by address and length of the PMU DFS registers
- #clock-cells : should be set to 1.
diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
index d9ae97fb43c4..6a3681e3d6db 100644
--- a/drivers/clk/mvebu/Makefile
+++ b/drivers/clk/mvebu/Makefile
@@ -9,7 +9,7 @@ obj-$(CONFIG_ARMADA_39X_CLK) += armada-39x.o
obj-$(CONFIG_ARMADA_37XX_CLK) += armada-37xx-xtal.o
obj-$(CONFIG_ARMADA_37XX_CLK) += armada-37xx-tbg.o
obj-$(CONFIG_ARMADA_37XX_CLK) += armada-37xx-periph.o
-obj-$(CONFIG_ARMADA_XP_CLK) += armada-xp.o
+obj-$(CONFIG_ARMADA_XP_CLK) += armada-xp.o mv98dx3236-corediv.o
obj-$(CONFIG_ARMADA_AP806_SYSCON) += ap806-system-controller.o
obj-$(CONFIG_ARMADA_CP110_SYSCON) += cp110-system-controller.o
obj-$(CONFIG_DOVE_CLK) += dove.o dove-divider.o
diff --git a/drivers/clk/mvebu/armada-xp.c b/drivers/clk/mvebu/armada-xp.c
index b3094315a3c0..0413bf8284e0 100644
--- a/drivers/clk/mvebu/armada-xp.c
+++ b/drivers/clk/mvebu/armada-xp.c
@@ -52,6 +52,12 @@ static u32 __init axp_get_tclk_freq(void __iomem *sar)
return 250000000;
}

+/* MV98DX3236 TCLK frequency is fixed to 200MHz */
+static u32 __init mv98dx3236_get_tclk_freq(void __iomem *sar)
+{
+ return 200000000;
+}
+
static const u32 axp_cpu_freqs[] __initconst = {
1000000000,
1066000000,
@@ -89,6 +95,12 @@ static u32 __init axp_get_cpu_freq(void __iomem *sar)
return cpu_freq;
}

+/* MV98DX3236 CLK frequency is fixed to 800MHz */
+static u32 __init mv98dx3236_get_cpu_freq(void __iomem *sar)
+{
+ return 800000000;
+}
+
static const int axp_nbclk_ratios[32][2] __initconst = {
{0, 1}, {1, 2}, {2, 2}, {2, 2},
{1, 2}, {1, 2}, {1, 1}, {2, 3},
@@ -158,6 +170,14 @@ static const struct coreclk_soc_desc axp_coreclks = {
.num_ratios = ARRAY_SIZE(axp_coreclk_ratios),
};

+static const struct coreclk_soc_desc mv98dx3236_coreclks = {
+ .get_tclk_freq = mv98dx3236_get_tclk_freq,
+ .get_cpu_freq = mv98dx3236_get_cpu_freq,
+ .get_clk_ratio = NULL,
+ .ratios = NULL,
+ .num_ratios = 0,
+};
+
/*
* Clock Gating Control
*/
@@ -195,6 +215,15 @@ static const struct clk_gating_soc_desc axp_gating_desc[] __initconst = {
{ }
};

+static const struct clk_gating_soc_desc mv98dx3236_gating_desc[] __initconst = {
+ { "ge1", NULL, 3, 0 },
+ { "ge0", NULL, 4, 0 },
+ { "pex00", NULL, 5, 0 },
+ { "sdio", NULL, 17, 0 },
+ { "xor0", NULL, 22, 0 },
+ { }
+};
+
static void __init axp_clk_init(struct device_node *np)
{
struct device_node *cgnp =
@@ -206,3 +235,16 @@ static void __init axp_clk_init(struct device_node *np)
mvebu_clk_gating_setup(cgnp, axp_gating_desc);
}
CLK_OF_DECLARE(axp_clk, "marvell,armada-xp-core-clock", axp_clk_init);
+
+static void __init mv98dx3236_clk_init(struct device_node *np)
+{
+ struct device_node *cgnp =
+ of_find_compatible_node(NULL, NULL, "marvell,armada-xp-gating-clock");
+
+ mvebu_coreclk_setup(np, &mv98dx3236_coreclks);
+
+ if (cgnp)
+ mvebu_clk_gating_setup(cgnp, mv98dx3236_gating_desc);
+}
+CLK_OF_DECLARE(mv98dx3236_clk, "marvell,mv98dx3236-core-clock",
+ mv98dx3236_clk_init);
diff --git a/drivers/clk/mvebu/clk-cpu.c b/drivers/clk/mvebu/clk-cpu.c
index 5837eb8a212f..29f295e7a36b 100644
--- a/drivers/clk/mvebu/clk-cpu.c
+++ b/drivers/clk/mvebu/clk-cpu.c
@@ -165,7 +165,9 @@ static const struct clk_ops cpu_ops = {
.set_rate = clk_cpu_set_rate,
};

-static void __init of_cpu_clk_setup(struct device_node *node)
+/* Add parameter to allow this to support different clock operations. */
+static void __init _of_cpu_clk_setup(struct device_node *node,
+ const struct clk_ops *cpu_clk_ops)
{
struct cpu_clk *cpuclk;
void __iomem *clock_complex_base = of_iomap(node, 0);
@@ -218,7 +220,7 @@ static void __init of_cpu_clk_setup(struct device_node *node)
cpuclk[cpu].hw.init = &init;

init.name = cpuclk[cpu].clk_name;
- init.ops = &cpu_ops;
+ init.ops = cpu_clk_ops;
init.flags = 0;
init.parent_names = &cpuclk[cpu].parent_name;
init.num_parents = 1;
@@ -243,5 +245,30 @@ static void __init of_cpu_clk_setup(struct device_node *node)
iounmap(clock_complex_base);
}

+/* Use this function to call the generic setup with the correct
+ * clock operation
+ */
+static void __init of_cpu_clk_setup(struct device_node *node)
+{
+ _of_cpu_clk_setup(node, &cpu_ops);
+}
+
CLK_OF_DECLARE(armada_xp_cpu_clock, "marvell,armada-xp-cpu-clock",
- of_cpu_clk_setup);
+ of_cpu_clk_setup);
+
+/* Define the clock and operations for the mv98dx3236 - it cannot perform
+ * any operations.
+ */
+static const struct clk_ops mv98dx3236_cpu_ops = {
+ .recalc_rate = NULL,
+ .round_rate = NULL,
+ .set_rate = NULL,
+};
+
+static void __init of_mv98dx3236_cpu_clk_setup(struct device_node *node)
+{
+ _of_cpu_clk_setup(node, &mv98dx3236_cpu_ops);
+}
+
+CLK_OF_DECLARE(mv98dx3236_cpu_clock, "marvell,mv98dx3236-cpu-clock",
+ of_mv98dx3236_cpu_clk_setup);
diff --git a/drivers/clk/mvebu/mv98dx3236-corediv.c b/drivers/clk/mvebu/mv98dx3236-corediv.c
new file mode 100644
index 000000000000..3060764a8e5d
--- /dev/null
+++ b/drivers/clk/mvebu/mv98dx3236-corediv.c
@@ -0,0 +1,207 @@
+/*
+ * MV98DX3236 Core divider clock
+ *
+ * Copyright (C) 2015 Allied Telesis Labs
+ *
+ * Based on armada-xp-corediv.c
+ * Copyright (C) 2015 Marvell
+ *
+ * John Thompson <john.thompson@xxxxxxxxxxxxxxxxxxx>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+#include <linux/kernel.h>
+#include <linux/clk-provider.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include "common.h"
+
+#define CORE_CLK_DIV_RATIO_MASK 0xff
+
+#define CLK_DIV_RATIO_NAND_MASK 0x0f
+#define CLK_DIV_RATIO_NAND_OFFSET 6
+#define CLK_DIV_RATIO_NAND_FORCE_RELOAD_BIT 26
+
+#define RATIO_RELOAD_BIT BIT(10)
+#define RATIO_REG_OFFSET 0x08
+
+/*
+ * This structure represents one core divider clock for the clock
+ * framework, and is dynamically allocated for each core divider clock
+ * existing in the current SoC.
+ */
+struct clk_corediv {
+ struct clk_hw hw;
+ void __iomem *reg;
+ spinlock_t lock;
+};
+
+static struct clk_onecell_data clk_data;
+
+
+#define to_corediv_clk(p) container_of(p, struct clk_corediv, hw)
+
+static int mv98dx3236_corediv_is_enabled(struct clk_hw *hwclk)
+{
+ /* Core divider is always active */
+ return 1;
+}
+
+static int mv98dx3236_corediv_enable(struct clk_hw *hwclk)
+{
+ /* always succeeds */
+ return 0;
+}
+
+static void mv98dx3236_corediv_disable(struct clk_hw *hwclk)
+{
+ /* can't be disabled so is left alone */
+}
+
+static unsigned long mv98dx3236_corediv_recalc_rate(struct clk_hw *hwclk,
+ unsigned long parent_rate)
+{
+ struct clk_corediv *corediv = to_corediv_clk(hwclk);
+ u32 reg, div;
+
+ reg = readl(corediv->reg + RATIO_REG_OFFSET);
+ div = (reg >> CLK_DIV_RATIO_NAND_OFFSET) & CLK_DIV_RATIO_NAND_MASK;
+ return parent_rate / div;
+}
+
+static long mv98dx3236_corediv_round_rate(struct clk_hw *hwclk,
+ unsigned long rate, unsigned long *parent_rate)
+{
+ /* Valid ratio are 1:4, 1:5, 1:6 and 1:8 */
+ u32 div;
+
+ div = *parent_rate / rate;
+ if (div < 4)
+ div = 4;
+ else if (div > 6)
+ div = 8;
+
+ return *parent_rate / div;
+}
+
+static int mv98dx3236_corediv_set_rate(struct clk_hw *hwclk, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct clk_corediv *corediv = to_corediv_clk(hwclk);
+ unsigned long flags = 0;
+ u32 reg, div;
+
+ div = parent_rate / rate;
+
+ spin_lock_irqsave(&corediv->lock, flags);
+
+ /* Write new divider to the divider ratio register */
+ reg = readl(corediv->reg + RATIO_REG_OFFSET);
+ reg &= ~(CLK_DIV_RATIO_NAND_MASK << CLK_DIV_RATIO_NAND_OFFSET);
+ reg |= (div & CLK_DIV_RATIO_NAND_MASK) << CLK_DIV_RATIO_NAND_OFFSET;
+ writel(reg, corediv->reg + RATIO_REG_OFFSET);
+
+ /* Set reload-force for this clock */
+ reg = readl(corediv->reg) | BIT(CLK_DIV_RATIO_NAND_FORCE_RELOAD_BIT);
+ writel(reg, corediv->reg);
+
+ /* Now trigger the clock update */
+ reg = readl(corediv->reg + RATIO_REG_OFFSET) | RATIO_RELOAD_BIT;
+ writel(reg, corediv->reg + RATIO_REG_OFFSET);
+
+ /*
+ * Wait for clocks to settle down, and then clear all the
+ * ratios request and the reload request.
+ */
+ udelay(1000);
+ reg &= ~(CORE_CLK_DIV_RATIO_MASK | RATIO_RELOAD_BIT);
+ writel(reg, corediv->reg + RATIO_REG_OFFSET);
+ udelay(1000);
+
+ spin_unlock_irqrestore(&corediv->lock, flags);
+
+ return 0;
+}
+
+static const struct clk_ops ops = {
+ .enable = mv98dx3236_corediv_enable,
+ .disable = mv98dx3236_corediv_disable,
+ .is_enabled = mv98dx3236_corediv_is_enabled,
+ .recalc_rate = mv98dx3236_corediv_recalc_rate,
+ .round_rate = mv98dx3236_corediv_round_rate,
+ .set_rate = mv98dx3236_corediv_set_rate,
+};
+
+static void __init mv98dx3236_corediv_clk_init(struct device_node *node)
+{
+ struct clk_init_data init;
+ struct clk_corediv *corediv;
+ struct clk **clks;
+ void __iomem *base;
+ const __be32 *off;
+ const char *parent_name;
+ const char *clk_name;
+ int len;
+ struct device_node *dfx_node;
+
+ dfx_node = of_parse_phandle(node, "base", 0);
+ if (WARN_ON(!dfx_node))
+ return;
+
+ off = of_get_property(node, "reg", &len);
+ if (WARN_ON(!off))
+ return;
+
+ base = of_iomap(dfx_node, 0);
+ if (WARN_ON(!base))
+ return;
+
+ of_node_put(dfx_node);
+
+ parent_name = of_clk_get_parent_name(node, 0);
+
+ clk_data.clk_num = 1;
+
+ /* clks holds the clock array */
+ clks = kcalloc(clk_data.clk_num, sizeof(struct clk *),
+ GFP_KERNEL);
+ if (WARN_ON(!clks))
+ goto err_unmap;
+ /* corediv holds the clock specific array */
+ corediv = kcalloc(clk_data.clk_num, sizeof(struct clk_corediv),
+ GFP_KERNEL);
+ if (WARN_ON(!corediv))
+ goto err_free_clks;
+
+ spin_lock_init(&corediv->lock);
+
+ of_property_read_string_index(node, "clock-output-names",
+ 0, &clk_name);
+
+ init.num_parents = 1;
+ init.parent_names = &parent_name;
+ init.name = clk_name;
+ init.ops = &ops;
+ init.flags = 0;
+
+ corediv[0].reg = (void *)((int)base + be32_to_cpu(*off));
+ corediv[0].hw.init = &init;
+
+ clks[0] = clk_register(NULL, &corediv[0].hw);
+ WARN_ON(IS_ERR(clks[0]));
+
+ clk_data.clks = clks;
+ of_clk_add_provider(node, of_clk_src_onecell_get, &clk_data);
+ return;
+
+err_free_clks:
+ kfree(clks);
+err_unmap:
+ iounmap(base);
+}
+
+CLK_OF_DECLARE(mv98dx3236_corediv_clk, "marvell,mv98dx3236-corediv-clock",
+ mv98dx3236_corediv_clk_init);
--
2.11.0.24.ge6920cf