diff options
Diffstat (limited to 'target/linux/bcm53xx/patches-4.4/830-clk-bcm-Add-driver-for-BCM53573-ILP-clock.patch')
| -rw-r--r-- | target/linux/bcm53xx/patches-4.4/830-clk-bcm-Add-driver-for-BCM53573-ILP-clock.patch | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/target/linux/bcm53xx/patches-4.4/830-clk-bcm-Add-driver-for-BCM53573-ILP-clock.patch b/target/linux/bcm53xx/patches-4.4/830-clk-bcm-Add-driver-for-BCM53573-ILP-clock.patch new file mode 100644 index 0000000000..322a1660d0 --- /dev/null +++ b/target/linux/bcm53xx/patches-4.4/830-clk-bcm-Add-driver-for-BCM53573-ILP-clock.patch @@ -0,0 +1,258 @@ +From 1909c8bf322e0bbb068d57c370c5b64906a8c5a7 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl> +Date: Fri, 29 Jul 2016 14:48:19 +0200 +Subject: [PATCH V6] 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) and so it should +be defined as one of its subnodes (subdevices). For more details see +Documentation entry. + +Unfortunately there isn't a set of registers related to ILP clock only. +We use registers 0x66c, 0x674 and 0x6dc and between them there are e.g. +"retention*" and "control_ext" regs. This is why this driver maps all +0x1000 B of space. + +Signed-off-by: Rafał Miłecki <rafal@milecki.pl> +--- +V2: Rebase on top of clk-next + Use ALP as parent clock + Improve comments + Switch from ioremap_nocache to ioremap + Check of_clk_add_provide result for error +V3: Drop #include <linux/moduleh> + Make ILP DT entry part of PMU + Describe ILP as subdevice of PMU in Documentation +V4: Use BCM53573 name as suggested by Jon and Ray. It seems "Northstar" + (even if used in some resources) should be used in relation to + Cortex-A9 devices only. +V5: Rename remaining "ns" references to "bcm53573", sorry, I sent V4 too + early. +V6: Drop #include <linux/clk.h> + Use "int" as type where it matches usage + Add cpu_relax() in the loop + Add disable callback + Use _hw_ functions for registering struct clk_hw (new API) + + Thanks a lot Stephen! +--- + .../bindings/clock/brcm,bcm53573-ilp.txt | 40 ++++++ + drivers/clk/bcm/Makefile | 1 + + drivers/clk/bcm/clk-bcm53573-ilp.c | 157 +++++++++++++++++++++ + 3 files changed, 198 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 +1,40 @@ ++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. ++ ++This clock is part of PMU (Power Management Unit), a Broadcom's device ++handing power-related aspects. Please note PMU contains more subdevices, ++ILP is only one of them. ++ ++ILP's rate has to be calculated on runtime and it depends on ALP clock ++which has to be referenced. ++ ++Required properties: ++- compatible: "brcm,bcm53573-ilp" ++- reg: iomem address range of PMU (Power Management Unit) ++- reg-names: "pmu", the only needed & supported reg right now ++- clocks: has to reference an ALP clock ++- #clock-cells: should be <0> ++ ++Example: ++ ++pmu@18012000 { ++ compatible = "simple-bus"; ++ ranges = <0x00000000 0x18012000 0x00001000>; ++ #address-cells = <1>; ++ #size-cells = <1>; ++ ++ ilp: ilp@0 { ++ compatible = "brcm,bcm53573-ilp"; ++ reg = <0 0x1000>; ++ reg-names = "pmu"; ++ clocks = <&alp>; ++ #clock-cells = <0>; ++ clock-output-names = "ilp"; ++ }; ++}; +--- a/drivers/clk/bcm/Makefile ++++ b/drivers/clk/bcm/Makefile +@@ -8,3 +8,4 @@ obj-$(CONFIG_COMMON_CLK_IPROC) += clk-ns + obj-$(CONFIG_ARCH_BCM_CYGNUS) += clk-cygnus.o + obj-$(CONFIG_ARCH_BCM_NSP) += clk-nsp.o + obj-$(CONFIG_ARCH_BCM_5301X) += clk-nsp.o ++obj-$(CONFIG_ARCH_BCM_53573) += clk-bcm53573-ilp.o +--- /dev/null ++++ b/drivers/clk/bcm/clk-bcm53573-ilp.c +@@ -0,0 +1,157 @@ ++/* ++ * 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/of.h> ++#include <linux/of_address.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; ++ void __iomem *pmu; ++}; ++ ++static int bcm53573_ilp_enable(struct clk_hw *hw) ++{ ++ struct bcm53573_ilp *ilp = container_of(hw, struct bcm53573_ilp, hw); ++ ++ writel(0x10199, ilp->pmu + PMU_SLOW_CLK_PERIOD); ++ writel(0x10000, ilp->pmu + 0x674); ++ ++ return 0; ++} ++ ++static void bcm53573_ilp_disable(struct clk_hw *hw) ++{ ++ struct bcm53573_ilp *ilp = container_of(hw, struct bcm53573_ilp, hw); ++ ++ writel(0, ilp->pmu + PMU_SLOW_CLK_PERIOD); ++ writel(0, ilp->pmu + 0x674); ++} ++ ++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); ++ void __iomem *pmu = ilp->pmu; ++ u32 last_val, cur_val; ++ int sum = 0, num = 0, loop_num = 0; ++ int avg; ++ ++ /* Enable measurement */ ++ writel(XTAL_CTL_EN, pmu + PMU_XTAL_FREQ_RATIO); ++ ++ /* Read initial value */ ++ last_val = readl(pmu + PMU_XTAL_FREQ_RATIO) & 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) { ++ cur_val = readl(pmu + PMU_XTAL_FREQ_RATIO) & 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 */ ++ writel(0x0, pmu + PMU_XTAL_FREQ_RATIO); ++ ++ 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 resource res; ++ struct clk_init_data init = { 0 }; ++ const char *parent_name; ++ int index; ++ 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; ++ } ++ ++ /* TODO: This looks generic, try making it OF helper. */ ++ index = of_property_match_string(np, "reg-names", "pmu"); ++ if (index < 0) { ++ err = index; ++ goto err_free_ilp; ++ } ++ err = of_address_to_resource(np, index, &res); ++ if (err) ++ goto err_free_ilp; ++ ilp->pmu = ioremap(res.start, resource_size(&res)); ++ if (IS_ERR(ilp->pmu)) { ++ err = PTR_ERR(ilp->pmu); ++ 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_unmap_pmu; ++ ++ 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_unmap_pmu: ++ iounmap(ilp->pmu); ++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); |