From c7bb4fc16ead2883a9e4eece2781fa78a0837735 Mon Sep 17 00:00:00 2001 From: Jonas Jensen Date: Tue, 28 Jan 2014 12:09:11 +0100 Subject: [PATCH] clk: add MOXA ART SoCs clock driver MOXA ART SoCs allow to determine PLL output and APB frequencies by reading registers holding multiplier and divisor information. Add a clock driver for this SoC. Signed-off-by: Jonas Jensen Signed-off-by: Mike Turquette --- .../bindings/clock/moxa,moxart-clock.txt | 48 +++++++++++ drivers/clk/Makefile | 1 + drivers/clk/clk-moxart.c | 97 ++++++++++++++++++++++ 3 files changed, 146 insertions(+) create mode 100644 Documentation/devicetree/bindings/clock/moxa,moxart-clock.txt create mode 100644 drivers/clk/clk-moxart.c diff --git a/Documentation/devicetree/bindings/clock/moxa,moxart-clock.txt b/Documentation/devicetree/bindings/clock/moxa,moxart-clock.txt new file mode 100644 index 0000000..fedea84 --- /dev/null +++ b/Documentation/devicetree/bindings/clock/moxa,moxart-clock.txt @@ -0,0 +1,48 @@ +Device Tree Clock bindings for arch-moxart + +This binding uses the common clock binding[1]. + +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt + +MOXA ART SoCs allow to determine PLL output and APB frequencies +by reading registers holding multiplier and divisor information. + + +PLL: + +Required properties: +- compatible : Must be "moxa,moxart-pll-clock" +- #clock-cells : Should be 0 +- reg : Should contain registers location and length +- clocks : Should contain phandle + clock-specifier for the parent clock + +Optional properties: +- clock-output-names : Should contain clock name + + +APB: + +Required properties: +- compatible : Must be "moxa,moxart-apb-clock" +- #clock-cells : Should be 0 +- reg : Should contain registers location and length +- clocks : Should contain phandle + clock-specifier for the parent clock + +Optional properties: +- clock-output-names : Should contain clock name + + +For example: + + clk_pll: clk_pll@98100000 { + compatible = "moxa,moxart-pll-clock"; + #clock-cells = <0>; + reg = <0x98100000 0x34>; + }; + + clk_apb: clk_apb@98100000 { + compatible = "moxa,moxart-apb-clock"; + #clock-cells = <0>; + reg = <0x98100000 0x34>; + clocks = <&clk_pll>; + }; diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile index a367a98..48a7ef3 100644 --- a/drivers/clk/Makefile +++ b/drivers/clk/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_ARCH_EFM32) += clk-efm32gg.o obj-$(CONFIG_ARCH_HIGHBANK) += clk-highbank.o obj-$(CONFIG_MACH_LOONGSON1) += clk-ls1x.o obj-$(CONFIG_COMMON_CLK_MAX77686) += clk-max77686.o +obj-$(CONFIG_ARCH_MOXART) += clk-moxart.o obj-$(CONFIG_ARCH_NOMADIK) += clk-nomadik.o obj-$(CONFIG_ARCH_NSPIRE) += clk-nspire.o obj-$(CONFIG_CLK_PPC_CORENET) += clk-ppc-corenet.o diff --git a/drivers/clk/clk-moxart.c b/drivers/clk/clk-moxart.c new file mode 100644 index 0000000..30a3b69 --- /dev/null +++ b/drivers/clk/clk-moxart.c @@ -0,0 +1,97 @@ +/* + * MOXA ART SoCs clock driver. + * + * Copyright (C) 2013 Jonas Jensen + * + * Jonas Jensen + * + * 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 +#include +#include +#include + +void __init moxart_of_pll_clk_init(struct device_node *node) +{ + static void __iomem *base; + struct clk *clk, *ref_clk; + unsigned int mul; + const char *name = node->name; + const char *parent_name; + + of_property_read_string(node, "clock-output-names", &name); + parent_name = of_clk_get_parent_name(node, 0); + + base = of_iomap(node, 0); + if (!base) { + pr_err("%s: of_iomap failed\n", node->full_name); + return; + } + + mul = readl(base + 0x30) >> 3 & 0x3f; + iounmap(base); + + ref_clk = of_clk_get(node, 0); + if (IS_ERR(ref_clk)) { + pr_err("%s: of_clk_get failed\n", node->full_name); + return; + } + + clk = clk_register_fixed_factor(NULL, name, parent_name, 0, mul, 1); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock\n", node->full_name); + return; + } + + clk_register_clkdev(clk, NULL, name); + of_clk_add_provider(node, of_clk_src_simple_get, clk); +} +CLK_OF_DECLARE(moxart_pll_clock, "moxa,moxart-pll-clock", + moxart_of_pll_clk_init); + +void __init moxart_of_apb_clk_init(struct device_node *node) +{ + static void __iomem *base; + struct clk *clk, *pll_clk; + unsigned int div, val; + unsigned int div_idx[] = { 2, 3, 4, 6, 8}; + const char *name = node->name; + const char *parent_name; + + of_property_read_string(node, "clock-output-names", &name); + parent_name = of_clk_get_parent_name(node, 0); + + base = of_iomap(node, 0); + if (!base) { + pr_err("%s: of_iomap failed\n", node->full_name); + return; + } + + val = readl(base + 0xc) >> 4 & 0x7; + iounmap(base); + + if (val > 4) + val = 0; + div = div_idx[val] * 2; + + pll_clk = of_clk_get(node, 0); + if (IS_ERR(pll_clk)) { + pr_err("%s: of_clk_get failed\n", node->full_name); + return; + } + + clk = clk_register_fixed_factor(NULL, name, parent_name, 0, 1, div); + if (IS_ERR(clk)) { + pr_err("%s: failed to register clock\n", node->full_name); + return; + } + + clk_register_clkdev(clk, NULL, name); + of_clk_add_provider(node, of_clk_src_simple_get, clk); +} +CLK_OF_DECLARE(moxart_apb_clock, "moxa,moxart-apb-clock", + moxart_of_apb_clk_init); -- 2.7.4