[PATCH 5/8] ARM: zynq: add COMMON_CLK support

From: Josh Cartwright
Date: Wed Oct 31 2012 - 19:13:25 EST

Add support for COMMON_CLK, and provide simplified models for the
necessary clocks on the zynq-7000. Currently, the PLLs, the CPU clock
network, and the basic peripheral clock networks (for SDIO, SMC, SPI,
QSPI, UART) are modelled.

Signed-off-by: Josh Cartwright <josh.cartwright@xxxxxx>
---
.../devicetree/bindings/clock/zynq-7000.txt | 55 ++++
arch/arm/Kconfig | 1 +
arch/arm/boot/dts/zynq-7000.dtsi | 56 ++++
arch/arm/boot/dts/zynq-zc702.dts | 4 +
arch/arm/mach-zynq/common.c | 11 +
drivers/clk/Makefile | 1 +
drivers/clk/clk-zynq.c | 355 +++++++++++++++++++++
include/linux/clk/zynq.h | 24 ++
8 files changed, 507 insertions(+)
create mode 100644 Documentation/devicetree/bindings/clock/zynq-7000.txt
create mode 100644 drivers/clk/clk-zynq.c
create mode 100644 include/linux/clk/zynq.h

diff --git a/Documentation/devicetree/bindings/clock/zynq-7000.txt b/Documentation/devicetree/bindings/clock/zynq-7000.txt
new file mode 100644
index 0000000..2e21fc1
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/zynq-7000.txt
@@ -0,0 +1,55 @@
+Device Tree Clock bindings for the Zynq 7000 EPP
+
+The Zynq EPP has several different clk providers, each with there own bindings.
+The purpose of this document is to document their usage.
+
+See clock_bindings.txt for more information on the generic clock bindings.
+See Chapter 25 of Zynq TRM for more information about Zynq clocks.
+
+== PLLs ==
+
+Used to describe the ARM_PLL, DDR_PLL, and IO_PLL.
+
+Required properties:
+- #clock-cells : shall be 0 (only one clock is output from this node)
+- compatible : "xlnx,zynq-pll"
+- reg : pair of u32 values, which are the address offsets within the SLCR
+ of the relevant PLL_CTRL register and PLL_CFG register respectively
+- clocks : phandle for parent clock. should be the phandle for ps_clk
+
+Optional properties:
+- clock-output-names : name of the output clock
+
+Example:
+ armpll: armpll {
+ #clock-cells = <0>;
+ compatible = "xlnx,zynq-pll";
+ clocks = <&ps_clk>;
+ reg = <0x100 0x110>;
+ clock-output-names = "armpll";
+ };
+
+== Peripheral clocks ==
+
+Describes clock node for the SDIO, SMC, SPI, QSPI, and UART clocks.
+
+Required properties:
+- #clock-cells : shall be 1
+- compatible : "xlnx,zynq-periph-clock"
+- reg : a single u32 value, describing the offset within the SLCR where
+ the CLK_CTRL register is found for this peripheral
+- clocks : phandle for parent clocks. should hold phandles for
+ the IO_PLL, ARM_PLL, and DDR_PLL in order
+
+Optional properties:
+- clock-output-names : name of the output clock
+
+Example:
+ uart_clk: uart_clk {
+ #clock-cells = <1>;
+ compatible = "xlnx,zynq-periph-clock";
+ clocks = <&iopll &armpll &ddrpll>;
+ reg = <0x154>;
+ clock-output-names = "uart0_ref_clk",
+ "uart1_ref_clk";
+ };
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 21ed87b..ccfe0ab 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -959,6 +959,7 @@ config ARCH_ZYNQ
bool "Xilinx Zynq ARM Cortex A9 Platform"
select ARM_AMBA
select ARM_GIC
+ select COMMON_CLK
select CPU_V7
select GENERIC_CLOCKEVENTS
select ICST
diff --git a/arch/arm/boot/dts/zynq-7000.dtsi b/arch/arm/boot/dts/zynq-7000.dtsi
index 8b30e59..bb3085c 100644
--- a/arch/arm/boot/dts/zynq-7000.dtsi
+++ b/arch/arm/boot/dts/zynq-7000.dtsi
@@ -53,5 +53,61 @@
interrupts = <0 50 4>;
clock = <50000000>;
};
+
+ slcr: slcr@f8000000 {
+ compatible = "xlnx,zynq-slcr";
+ reg = <0xF8000000 0x1000>;
+
+ clocks {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ps_clk: ps_clk {
+ #clock-cells = <0>;
+ compatible = "fixed-clock";
+ /* clock-frequency set in board-specific file */
+ clock-output-names = "ps_clk";
+ };
+ armpll: armpll {
+ #clock-cells = <0>;
+ compatible = "xlnx,zynq-pll";
+ clocks = <&ps_clk>;
+ reg = <0x100 0x110>;
+ clock-output-names = "armpll";
+ };
+ ddrpll: ddrpll {
+ #clock-cells = <0>;
+ compatible = "xlnx,zynq-pll";
+ clocks = <&ps_clk>;
+ reg = <0x104 0x114>;
+ clock-output-names = "ddrpll";
+ };
+ iopll: iopll {
+ #clock-cells = <0>;
+ compatible = "xlnx,zynq-pll";
+ clocks = <&ps_clk>;
+ reg = <0x108 0x118>;
+ clock-output-names = "iopll";
+ };
+ uart_clk: uart_clk {
+ #clock-cells = <1>;
+ compatible = "xlnx,zynq-periph-clock";
+ clocks = <&iopll &armpll &ddrpll>;
+ reg = <0x154>;
+ clock-output-names = "uart0_ref_clk",
+ "uart1_ref_clk";
+ };
+ cpu_clk: cpu_clk {
+ #clock-cells = <1>;
+ compatible = "xlnx,zynq-cpu-clock";
+ clocks = <&iopll &armpll &ddrpll>;
+ reg = <0x120 0x1C4>;
+ clock-output-names = "cpu_6x4x",
+ "cpu_3x2x",
+ "cpu_2x",
+ "cpu_1x";
+ };
+ };
+ };
};
};
diff --git a/arch/arm/boot/dts/zynq-zc702.dts b/arch/arm/boot/dts/zynq-zc702.dts
index e25a307..86f44d5 100644
--- a/arch/arm/boot/dts/zynq-zc702.dts
+++ b/arch/arm/boot/dts/zynq-zc702.dts
@@ -28,3 +28,7 @@
};

};
+
+&ps_clk {
+ clock-frequency = <33333330>;
+};
diff --git a/arch/arm/mach-zynq/common.c b/arch/arm/mach-zynq/common.c
index 447904b..f0cb3e4 100644
--- a/arch/arm/mach-zynq/common.c
+++ b/arch/arm/mach-zynq/common.c
@@ -19,6 +19,8 @@
#include <linux/cpumask.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
+#include <linux/clk/zynq.h>
+#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/of.h>
@@ -96,6 +98,15 @@ static struct map_desc io_desc[] __initdata = {

static void __init xilinx_zynq_timer_init(void)
{
+ struct device_node *np;
+ void __iomem *slcr;
+
+ np = of_find_compatible_node(NULL, NULL, "xlnx,zynq-slcr");
+ slcr = of_iomap(np, 0);
+ WARN_ON(!slcr);
+
+ xilinx_zynq_clocks_init(slcr);
+
xttcpss_timer_init();
}

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 71a25b9..d35a34c 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -19,6 +19,7 @@ endif
obj-$(CONFIG_MACH_LOONGSON1) += clk-ls1x.o
obj-$(CONFIG_ARCH_U8500) += ux500/
obj-$(CONFIG_ARCH_VT8500) += clk-vt8500.o
+obj-$(CONFIG_ARCH_ZYNQ) += clk-zynq.o

# Chip specific
obj-$(CONFIG_COMMON_CLK_WM831X) += clk-wm831x.o
diff --git a/drivers/clk/clk-zynq.c b/drivers/clk/clk-zynq.c
new file mode 100644
index 0000000..2afa84d
--- /dev/null
+++ b/drivers/clk/clk-zynq.c
@@ -0,0 +1,355 @@
+/*
+ * Copyright (c) 2012 National Instruments
+ *
+ * Josh Cartwright <josh.cartwright@xxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/clk-provider.h>
+
+static void __iomem *slcr_base;
+
+struct zynq_pll_clk {
+ struct clk_hw hw;
+ void __iomem *pll_ctrl;
+ void __iomem *pll_cfg;
+};
+
+#define to_zynq_pll_clk(hw) container_of(hw, struct zynq_pll_clk, hw)
+
+#define CTRL_PLL_FDIV(x) ((x)>>12)
+
+static unsigned long zynq_pll_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct zynq_pll_clk *pll = to_zynq_pll_clk(hw);
+ return parent_rate * CTRL_PLL_FDIV(ioread32(pll->pll_ctrl));
+}
+
+static const struct clk_ops zynq_pll_clk_ops = {
+ .recalc_rate = zynq_pll_recalc_rate,
+};
+
+static void __init zynq_pll_clk_setup(struct device_node *np)
+{
+ struct clk_init_data init;
+ struct zynq_pll_clk *pll;
+ const char *parent_name;
+ struct clk *clk;
+ u32 regs[2];
+ int ret;
+
+ ret = of_property_read_u32_array(np, "reg", regs, ARRAY_SIZE(regs));
+ WARN_ON(ret);
+
+ pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+ WARN_ON(!pll);
+
+ pll->pll_ctrl = slcr_base + regs[0];
+ pll->pll_cfg = slcr_base + regs[1];
+
+ of_property_read_string(np, "clock-output-names", &init.name);
+
+ init.ops = &zynq_pll_clk_ops;
+ parent_name = of_clk_get_parent_name(np, 0);
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ pll->hw.init = &init;
+
+ clk = clk_register(NULL, &pll->hw);
+ WARN_ON(IS_ERR(clk));
+
+ ret = of_clk_add_provider(np, of_clk_src_simple_get, clk);
+ WARN_ON(ret);
+}
+
+struct zynq_periph_clk {
+ struct clk_hw hw;
+ struct clk_onecell_data onecell_data;
+ struct clk *gates[2];
+ void __iomem *clk_ctrl;
+ spinlock_t clkact_lock;
+};
+
+#define to_zynq_periph_clk(hw) container_of(hw, struct zynq_periph_clk, hw)
+
+static const u8 periph_clk_parent_map[] = {
+ 0, 0, 1, 2
+};
+#define PERIPH_CLK_CTRL_SRC(x) (periph_clk_parent_map[((x)&3)>>4])
+#define PERIPH_CLK_CTRL_DIV(x) (((x)&0x3F00)>>8)
+
+static unsigned long zynq_periph_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct zynq_periph_clk *periph = to_zynq_periph_clk(hw);
+ return parent_rate / PERIPH_CLK_CTRL_DIV(ioread32(periph->clk_ctrl));
+}
+
+static u8 zynq_periph_get_parent(struct clk_hw *hw)
+{
+ struct zynq_periph_clk *periph = to_zynq_periph_clk(hw);
+ return PERIPH_CLK_CTRL_SRC(ioread32(periph->clk_ctrl));
+}
+
+static const struct clk_ops zynq_periph_clk_ops = {
+ .recalc_rate = zynq_periph_recalc_rate,
+ .get_parent = zynq_periph_get_parent,
+};
+
+static void __init zynq_periph_clk_setup(struct device_node *np)
+{
+ struct zynq_periph_clk *periph;
+ const char *parent_names[3];
+ struct clk_init_data init;
+ struct clk *clk;
+ int err;
+ u32 reg;
+ int i;
+
+ err = of_property_read_u32(np, "reg", &reg);
+ WARN_ON(err);
+
+ periph = kzalloc(sizeof(*periph), GFP_KERNEL);
+ WARN_ON(!periph);
+
+ periph->clk_ctrl = slcr_base + reg;
+ spin_lock_init(&periph->clkact_lock);
+
+ init.name = np->name;
+ init.ops = &zynq_periph_clk_ops;
+ for (i = 0; i < ARRAY_SIZE(parent_names); i++)
+ parent_names[i] = of_clk_get_parent_name(np, i);
+ init.parent_names = parent_names;
+ init.num_parents = ARRAY_SIZE(parent_names);
+
+ periph->hw.init = &init;
+
+ clk = clk_register(NULL, &periph->hw);
+ WARN_ON(IS_ERR(clk));
+
+ err = of_clk_add_provider(np, of_clk_src_simple_get, clk);
+ WARN_ON(err);
+
+ for (i = 0; i < 2; i++) {
+ const char *name;
+
+ err = of_property_read_string_index(np, "clock-output-names", i,
+ &name);
+ WARN_ON(err);
+
+ periph->gates[i] = clk_register_gate(NULL, name, np->name, 0,
+ periph->clk_ctrl, i, 0,
+ &periph->clkact_lock);
+ WARN_ON(IS_ERR(periph->gates[i]));
+ }
+
+ periph->onecell_data.clks = periph->gates;
+ periph->onecell_data.clk_num = i;
+
+ err = of_clk_add_provider(np, of_clk_src_onecell_get,
+ &periph->onecell_data);
+ WARN_ON(err);
+}
+
+/* CPU Clock domain is modelled as a mux with 4 children subclks, whose
+ * derivative rates depend on CLK_621_TRUE
+ */
+
+struct zynq_cpu_clk {
+ struct clk_hw hw;
+ struct clk_onecell_data onecell_data;
+ struct clk *subclks[4];
+ void __iomem *clk_ctrl;
+ spinlock_t clkact_lock;
+};
+
+#define to_zynq_cpu_clk(hw) container_of(hw, struct zynq_cpu_clk, hw)
+
+static const u8 zynq_cpu_clk_parent_map[] = {
+ 1, 1, 2, 0
+};
+#define CPU_CLK_SRCSEL(x) (zynq_cpu_clk_parent_map[(((x)&0x30)>>4)])
+#define CPU_CLK_CTRL_DIV(x) (((x)&0x3F00)>>8)
+
+static u8 zynq_cpu_clk_get_parent(struct clk_hw *hw)
+{
+ struct zynq_cpu_clk *cpuclk = to_zynq_cpu_clk(hw);
+ return CPU_CLK_SRCSEL(ioread32(cpuclk->clk_ctrl));
+}
+
+static unsigned long zynq_cpu_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct zynq_cpu_clk *cpuclk = to_zynq_cpu_clk(hw);
+ return parent_rate / CPU_CLK_CTRL_DIV(ioread32(cpuclk->clk_ctrl));
+}
+
+static const struct clk_ops zynq_cpu_clk_ops = {
+ .get_parent = zynq_cpu_clk_get_parent,
+ .recalc_rate = zynq_cpu_clk_recalc_rate,
+};
+
+struct zynq_cpu_subclk {
+ struct clk_hw hw;
+ void __iomem *clk_621;
+ enum {
+ CPU_SUBCLK_6X4X,
+ CPU_SUBCLK_3X2X,
+ CPU_SUBCLK_2X,
+ CPU_SUBCLK_1X,
+ } which;
+};
+
+#define CLK_621_TRUE(x) ((x)&1)
+
+#define to_zynq_cpu_subclk(hw) container_of(hw, struct zynq_cpu_subclk, hw);
+
+static unsigned long zynq_cpu_subclk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ unsigned long uninitialized_var(rate);
+ struct zynq_cpu_subclk *subclk;
+ bool is_621;
+
+ subclk = to_zynq_cpu_subclk(hw)
+ is_621 = CLK_621_TRUE(ioread32(subclk->clk_621));
+
+ switch (subclk->which) {
+ case CPU_SUBCLK_6X4X:
+ rate = parent_rate;
+ break;
+ case CPU_SUBCLK_3X2X:
+ rate = parent_rate / 2;
+ break;
+ case CPU_SUBCLK_2X:
+ rate = parent_rate / (is_621 ? 3 : 2);
+ break;
+ case CPU_SUBCLK_1X:
+ rate = parent_rate / (is_621 ? 6 : 4);
+ break;
+ };
+
+ return rate;
+}
+
+static const struct clk_ops zynq_cpu_subclk_ops = {
+ .recalc_rate = zynq_cpu_subclk_recalc_rate,
+};
+
+static struct clk *zynq_cpu_subclk_setup(struct device_node *np, u8 which,
+ void __iomem *clk_621)
+{
+ struct zynq_cpu_subclk *subclk;
+ struct clk_init_data init;
+ struct clk *clk;
+ int err;
+
+ err = of_property_read_string_index(np, "clock-output-names",
+ which, &init.name);
+ if (WARN_ON(err))
+ goto err_read_output_name;
+
+ subclk = kzalloc(sizeof(*subclk), GFP_KERNEL);
+ if (!subclk)
+ goto err_subclk_alloc;
+
+ subclk->clk_621 = clk_621;
+ subclk->which = which;
+
+ init.ops = &zynq_cpu_subclk_ops;
+ init.parent_names = &np->name;
+ init.num_parents = 1;
+
+ subclk->hw.init = &init;
+
+ clk = clk_register(NULL, &subclk->hw);
+ if (WARN_ON(IS_ERR(clk)))
+ goto err_clk_register;
+
+ return clk;
+
+err_clk_register:
+err_subclk_alloc:
+err_read_output_name:
+ return NULL;
+}
+
+static void __init zynq_cpu_clk_setup(struct device_node *np)
+{
+ struct zynq_cpu_clk *cpuclk;
+ const char *parent_names[3];
+ struct clk_init_data init;
+ void __iomem *clk_621;
+ struct clk *clk;
+ u32 reg[2];
+ int err;
+ int i;
+
+ err = of_property_read_u32_array(np, "reg", reg, ARRAY_SIZE(reg));
+ WARN_ON(err);
+
+ cpuclk = kzalloc(sizeof(*cpuclk), GFP_KERNEL);
+ WARN_ON(!cpuclk);
+
+ cpuclk->clk_ctrl = slcr_base + reg[0];
+ clk_621 = slcr_base + reg[1];
+ spin_lock_init(&cpuclk->clkact_lock);
+
+ init.name = np->name;
+ init.ops = &zynq_cpu_clk_ops;
+ for (i = 0; i < ARRAY_SIZE(parent_names); i++)
+ parent_names[i] = of_clk_get_parent_name(np, i);
+ init.parent_names = parent_names;
+ init.num_parents = ARRAY_SIZE(parent_names);
+
+ cpuclk->hw.init = &init;
+
+ clk = clk_register(NULL, &cpuclk->hw);
+ WARN_ON(IS_ERR(clk));
+
+ err = of_clk_add_provider(np, of_clk_src_simple_get, clk);
+ WARN_ON(err);
+
+ for (i = 0; i < 4; i++) {
+ cpuclk->subclks[i] = zynq_cpu_subclk_setup(np, i, clk_621);
+ WARN_ON(IS_ERR(cpuclk->subclks[i]));
+ }
+
+ cpuclk->onecell_data.clks = cpuclk->subclks;
+ cpuclk->onecell_data.clk_num = i;
+
+ err = of_clk_add_provider(np, of_clk_src_onecell_get,
+ &cpuclk->onecell_data);
+ WARN_ON(err);
+}
+
+static const __initconst struct of_device_id zynq_clk_match[] = {
+ { .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
+ { .compatible = "xlnx,zynq-pll", .data = zynq_pll_clk_setup, },
+ { .compatible = "xlnx,zynq-periph-clock",
+ .data = zynq_periph_clk_setup, },
+ { .compatible = "xlnx,zynq-cpu-clock", .data = zynq_cpu_clk_setup, },
+ {}
+};
+
+void __init xilinx_zynq_clocks_init(void __iomem *slcr)
+{
+ slcr_base = slcr;
+ of_clk_init(zynq_clk_match);
+}
diff --git a/include/linux/clk/zynq.h b/include/linux/clk/zynq.h
new file mode 100644
index 0000000..56be7cd
--- /dev/null
+++ b/include/linux/clk/zynq.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2012 National Instruments
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef __LINUX_CLK_ZYNQ_H_
+#define __LINUX_CLK_ZYNQ_H_
+
+void __init xilinx_zynq_clocks_init(void __iomem *slcr);
+
+#endif
--
1.8.0


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