mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-26 00:41:17 +00:00
225 lines
6.4 KiB
Diff
225 lines
6.4 KiB
Diff
From bd8dd593f7d2211f2273e05741d157b0c8d020ae Mon Sep 17 00:00:00 2001
|
|
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
|
|
Date: Tue, 13 Sep 2016 09:06:04 +0200
|
|
Subject: [PATCH] clk: bcm: Add driver for BCM53573 ILP clock
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
This clock is present on BCM53573 devices (including BCM47189) that use
|
|
Cortex-A7. ILP is a part of PMU (Power Management Unit) multi-function
|
|
device so we use syscon (and regmap) for it.
|
|
|
|
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
|
|
Acked-by: Rob Herring <robh@kernel.org>
|
|
[sboyd@codeaurora.org: Remove 0 from clk_init_data to silence sparse]
|
|
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
|
|
---
|
|
.../bindings/clock/brcm,bcm53573-ilp.txt | 36 +++++
|
|
drivers/clk/bcm/Makefile | 1 +
|
|
drivers/clk/bcm/clk-bcm53573-ilp.c | 148 +++++++++++++++++++++
|
|
3 files changed, 185 insertions(+)
|
|
create mode 100644 Documentation/devicetree/bindings/clock/brcm,bcm53573-ilp.txt
|
|
create mode 100644 drivers/clk/bcm/clk-bcm53573-ilp.c
|
|
|
|
--- /dev/null
|
|
+++ b/Documentation/devicetree/bindings/clock/brcm,bcm53573-ilp.txt
|
|
@@ -0,0 +1,36 @@
|
|
+Broadcom BCM53573 ILP clock
|
|
+===========================
|
|
+
|
|
+This binding uses the common clock binding:
|
|
+ Documentation/devicetree/bindings/clock/clock-bindings.txt
|
|
+
|
|
+This binding is used for ILP clock (sometimes referred as "slow clock")
|
|
+on Broadcom BCM53573 devices using Cortex-A7 CPU.
|
|
+
|
|
+ILP's rate has to be calculated on runtime and it depends on ALP clock
|
|
+which has to be referenced.
|
|
+
|
|
+This clock is part of PMU (Power Management Unit), a Broadcom's device
|
|
+handing power-related aspects. Its node must be sub-node of the PMU
|
|
+device.
|
|
+
|
|
+Required properties:
|
|
+- compatible: "brcm,bcm53573-ilp"
|
|
+- clocks: has to reference an ALP clock
|
|
+- #clock-cells: should be <0>
|
|
+- clock-output-names: from common clock bindings, should contain clock
|
|
+ name
|
|
+
|
|
+Example:
|
|
+
|
|
+pmu@18012000 {
|
|
+ compatible = "simple-mfd", "syscon";
|
|
+ reg = <0x18012000 0x00001000>;
|
|
+
|
|
+ ilp {
|
|
+ compatible = "brcm,bcm53573-ilp";
|
|
+ clocks = <&alp>;
|
|
+ #clock-cells = <0>;
|
|
+ clock-output-names = "ilp";
|
|
+ };
|
|
+};
|
|
--- a/drivers/clk/bcm/Makefile
|
|
+++ b/drivers/clk/bcm/Makefile
|
|
@@ -4,6 +4,7 @@ obj-$(CONFIG_CLK_BCM_KONA) += clk-bcm281
|
|
obj-$(CONFIG_CLK_BCM_KONA) += clk-bcm21664.o
|
|
obj-$(CONFIG_COMMON_CLK_IPROC) += clk-iproc-armpll.o clk-iproc-pll.o clk-iproc-asiu.o
|
|
obj-$(CONFIG_ARCH_BCM2835) += clk-bcm2835.o
|
|
+obj-$(CONFIG_ARCH_BCM_53573) += clk-bcm53573-ilp.o
|
|
obj-$(CONFIG_COMMON_CLK_IPROC) += clk-ns2.o
|
|
obj-$(CONFIG_ARCH_BCM_CYGNUS) += clk-cygnus.o
|
|
obj-$(CONFIG_ARCH_BCM_NSP) += clk-nsp.o
|
|
--- /dev/null
|
|
+++ b/drivers/clk/bcm/clk-bcm53573-ilp.c
|
|
@@ -0,0 +1,148 @@
|
|
+/*
|
|
+ * Copyright (C) 2016 Rafał Miłecki <rafal@milecki.pl>
|
|
+ *
|
|
+ * This program is free software; you can redistribute it and/or modify
|
|
+ * it under the terms of the GNU General Public License version 2 as
|
|
+ * published by the Free Software Foundation.
|
|
+ */
|
|
+
|
|
+#include <linux/clk-provider.h>
|
|
+#include <linux/err.h>
|
|
+#include <linux/io.h>
|
|
+#include <linux/mfd/syscon.h>
|
|
+#include <linux/of.h>
|
|
+#include <linux/of_address.h>
|
|
+#include <linux/regmap.h>
|
|
+#include <linux/slab.h>
|
|
+
|
|
+#define PMU_XTAL_FREQ_RATIO 0x66c
|
|
+#define XTAL_ALP_PER_4ILP 0x00001fff
|
|
+#define XTAL_CTL_EN 0x80000000
|
|
+#define PMU_SLOW_CLK_PERIOD 0x6dc
|
|
+
|
|
+struct bcm53573_ilp {
|
|
+ struct clk_hw hw;
|
|
+ struct regmap *regmap;
|
|
+};
|
|
+
|
|
+static int bcm53573_ilp_enable(struct clk_hw *hw)
|
|
+{
|
|
+ struct bcm53573_ilp *ilp = container_of(hw, struct bcm53573_ilp, hw);
|
|
+
|
|
+ regmap_write(ilp->regmap, PMU_SLOW_CLK_PERIOD, 0x10199);
|
|
+ regmap_write(ilp->regmap, 0x674, 0x10000);
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static void bcm53573_ilp_disable(struct clk_hw *hw)
|
|
+{
|
|
+ struct bcm53573_ilp *ilp = container_of(hw, struct bcm53573_ilp, hw);
|
|
+
|
|
+ regmap_write(ilp->regmap, PMU_SLOW_CLK_PERIOD, 0);
|
|
+ regmap_write(ilp->regmap, 0x674, 0);
|
|
+}
|
|
+
|
|
+static unsigned long bcm53573_ilp_recalc_rate(struct clk_hw *hw,
|
|
+ unsigned long parent_rate)
|
|
+{
|
|
+ struct bcm53573_ilp *ilp = container_of(hw, struct bcm53573_ilp, hw);
|
|
+ struct regmap *regmap = ilp->regmap;
|
|
+ u32 last_val, cur_val;
|
|
+ int sum = 0, num = 0, loop_num = 0;
|
|
+ int avg;
|
|
+
|
|
+ /* Enable measurement */
|
|
+ regmap_write(regmap, PMU_XTAL_FREQ_RATIO, XTAL_CTL_EN);
|
|
+
|
|
+ /* Read initial value */
|
|
+ regmap_read(regmap, PMU_XTAL_FREQ_RATIO, &last_val);
|
|
+ last_val &= XTAL_ALP_PER_4ILP;
|
|
+
|
|
+ /*
|
|
+ * At minimum we should loop for a bit to let hardware do the
|
|
+ * measurement. This isn't very accurate however, so for a better
|
|
+ * precision lets try getting 20 different values for and use average.
|
|
+ */
|
|
+ while (num < 20) {
|
|
+ regmap_read(regmap, PMU_XTAL_FREQ_RATIO, &cur_val);
|
|
+ cur_val &= XTAL_ALP_PER_4ILP;
|
|
+
|
|
+ if (cur_val != last_val) {
|
|
+ /* Got different value, use it */
|
|
+ sum += cur_val;
|
|
+ num++;
|
|
+ loop_num = 0;
|
|
+ last_val = cur_val;
|
|
+ } else if (++loop_num > 5000) {
|
|
+ /* Same value over and over, give up */
|
|
+ sum += cur_val;
|
|
+ num++;
|
|
+ break;
|
|
+ }
|
|
+
|
|
+ cpu_relax();
|
|
+ }
|
|
+
|
|
+ /* Disable measurement to save power */
|
|
+ regmap_write(regmap, PMU_XTAL_FREQ_RATIO, 0x0);
|
|
+
|
|
+ avg = sum / num;
|
|
+
|
|
+ return parent_rate * 4 / avg;
|
|
+}
|
|
+
|
|
+static const struct clk_ops bcm53573_ilp_clk_ops = {
|
|
+ .enable = bcm53573_ilp_enable,
|
|
+ .disable = bcm53573_ilp_disable,
|
|
+ .recalc_rate = bcm53573_ilp_recalc_rate,
|
|
+};
|
|
+
|
|
+static void bcm53573_ilp_init(struct device_node *np)
|
|
+{
|
|
+ struct bcm53573_ilp *ilp;
|
|
+ struct clk_init_data init = { };
|
|
+ const char *parent_name;
|
|
+ int err;
|
|
+
|
|
+ ilp = kzalloc(sizeof(*ilp), GFP_KERNEL);
|
|
+ if (!ilp)
|
|
+ return;
|
|
+
|
|
+ parent_name = of_clk_get_parent_name(np, 0);
|
|
+ if (!parent_name) {
|
|
+ err = -ENOENT;
|
|
+ goto err_free_ilp;
|
|
+ }
|
|
+
|
|
+ ilp->regmap = syscon_node_to_regmap(of_get_parent(np));
|
|
+ if (IS_ERR(ilp->regmap)) {
|
|
+ err = PTR_ERR(ilp->regmap);
|
|
+ goto err_free_ilp;
|
|
+ }
|
|
+
|
|
+ init.name = np->name;
|
|
+ init.ops = &bcm53573_ilp_clk_ops;
|
|
+ init.parent_names = &parent_name;
|
|
+ init.num_parents = 1;
|
|
+
|
|
+ ilp->hw.init = &init;
|
|
+ err = clk_hw_register(NULL, &ilp->hw);
|
|
+ if (err)
|
|
+ goto err_free_ilp;
|
|
+
|
|
+ err = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &ilp->hw);
|
|
+ if (err)
|
|
+ goto err_clk_hw_unregister;
|
|
+
|
|
+ return;
|
|
+
|
|
+err_clk_hw_unregister:
|
|
+ clk_hw_unregister(&ilp->hw);
|
|
+err_free_ilp:
|
|
+ kfree(ilp);
|
|
+ pr_err("Failed to init ILP clock: %d\n", err);
|
|
+}
|
|
+
|
|
+/* We need it very early for arch code, before device model gets ready */
|
|
+CLK_OF_DECLARE(bcm53573_ilp_clk, "brcm,bcm53573-ilp", bcm53573_ilp_init);
|