Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754731Ab3GYAqx (ORCPT ); Wed, 24 Jul 2013 20:46:53 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:34907 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754643Ab3GYAns (ORCPT ); Wed, 24 Jul 2013 20:43:48 -0400 From: Stephen Boyd To: Mike Turquette Cc: Saravana Kannan , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org Subject: [PATCH v1 07/14] clk: msm: Add support for branches/gate clocks Date: Wed, 24 Jul 2013 17:43:35 -0700 Message-Id: <1374713022-6049-8-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 1.8.3.4.840.g6a90778 In-Reply-To: <1374713022-6049-1-git-send-email-sboyd@codeaurora.org> References: <1374713022-6049-1-git-send-email-sboyd@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 9188 Lines: 315 Cc: devicetree@vger.kernel.org Signed-off-by: Stephen Boyd --- Documentation/devicetree/bindings/clock/msm.txt | 28 ++++ drivers/clk/msm/Makefile | 1 + drivers/clk/msm/clk-branch.c | 190 ++++++++++++++++++++++++ drivers/clk/msm/clk-branch.h | 48 ++++++ 4 files changed, 267 insertions(+) create mode 100644 drivers/clk/msm/clk-branch.c create mode 100644 drivers/clk/msm/clk-branch.h diff --git a/Documentation/devicetree/bindings/clock/msm.txt b/Documentation/devicetree/bindings/clock/msm.txt index f4595fa..6840398 100644 --- a/Documentation/devicetree/bindings/clock/msm.txt +++ b/Documentation/devicetree/bindings/clock/msm.txt @@ -69,3 +69,31 @@ Example: clocks = <&pxo>, <&pll2>, <&pll8>; }; +CXC Binding +----------- + +Required properties: +- compatible : shall be "qcom,cxc-clock". +- #clock-cells : from common clock binding; shall be set to 0. +- clocks : from common clock binding; shall be set to the source being gated + +Example: + gsbi5_uart_clk: gsbi5_uart_cxc { + #clock-cells = <0>; + compatible = "qcom,cxc-clock"; + clocks = <&gsbi5_uart_rcg>; + }; + +CXC With Hardware Gating Binding +-------------------------------- + +Required properties: +- compatible : shall be "qcom,cxc-hg-clock". +- #clock-cells : from common clock binding; shall be set to 0. +- clocks : from common clock binding; shall be set to the source being gated + + gsbi5_uart_ahb: gsbi5_uart_ahb { + #clock-cells = <0>; + compatible = "qcom,cxc-hg-clock"; + clocks = <&cfpb_clk>; + }; diff --git a/drivers/clk/msm/Makefile b/drivers/clk/msm/Makefile index fb78ac9..e1cee29 100644 --- a/drivers/clk/msm/Makefile +++ b/drivers/clk/msm/Makefile @@ -3,3 +3,4 @@ obj-$(CONFIG_COMMON_CLK_MSM) += clk-msm.o clk-msm-$(CONFIG_COMMON_CLK_MSM) += clk-pll.o clk-msm-$(CONFIG_COMMON_CLK_MSM) += clk-rcg.o clk-msm-$(CONFIG_COMMON_CLK_MSM) += clk-rcg2.o +clk-msm-$(CONFIG_COMMON_CLK_MSM) += clk-branch.o diff --git a/drivers/clk/msm/clk-branch.c b/drivers/clk/msm/clk-branch.c new file mode 100644 index 0000000..ff2e599 --- /dev/null +++ b/drivers/clk/msm/clk-branch.c @@ -0,0 +1,190 @@ +/* + * Copyright (c) 2013, The Linux Foundation. All rights reserved. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "clk-branch.h" + +/** + * struct clk_branch - gating clock with status bit and dynamic hardware gating + * + * @ctl_reg: clock control register + * @ctl_bit: ORed with @ctl_reg to enable the clock + * @hwcg_reg: dynamic hardware clock gating register + * @hwcg_bit: ORed with @hwcg_reg to enable dynamic hardware clock gating + * @halt_reg: halt register + * @halt_bit: ANDed with @halt_reg to test for clock halted + * @halt_check: type of halt checking to perform + * @hw: handle between common and hardware-specific interfaces + * @lock: register lock + * + * Clock which can gate its output. + */ +struct clk_branch { + void __iomem *ctl_reg; + void __iomem *hwcg_reg; + void __iomem *halt_reg; + + u8 ctl_bit; + u8 hwcg_bit; + u8 halt_bit; + u8 halt_check; + + struct clk_hw hw; + spinlock_t *lock; +}; + +#define to_clk_branch(_hw) container_of(_hw, struct clk_branch, hw) + +static bool clk_branch_is_halted(const struct clk_branch *br) +{ + bool invert = (br->halt_check == BRANCH_HALT_ENABLE); + u32 status_bit = readl_relaxed(br->halt_reg) & BIT(br->halt_bit); + return invert ? !status_bit : status_bit; +} + +static bool clk_branch_in_hwcg_mode(const struct clk_branch *br) +{ + if (!br->hwcg_reg) + return 0; + + return !!(readl_relaxed(br->hwcg_reg) & BIT(br->hwcg_bit)); +} + +static int clk_branch_wait(const struct clk_branch *br, bool enabling) +{ + bool voted = br->halt_check & BRANCH_VOTED; + const char *name = __clk_get_name(br->hw.clk); + + /* Skip checking halt bit if the clock is in hardware gated mode */ + if (clk_branch_in_hwcg_mode(br)) + return 0; + + if (br->halt_check == BRANCH_HALT_DELAY || (!enabling && voted)) { + udelay(10); + } else if (br->halt_check == BRANCH_HALT_ENABLE || + br->halt_check == BRANCH_HALT || + (enabling && voted)) { + int count = 200; + + while (count-- > 0) { + if (clk_branch_is_halted(br) == !enabling) + return 0; + udelay(1); + } + WARN("%s status stuck at 'o%s'", name, enabling ? "ff" : "n"); + return -EBUSY; + } + return 0; +} + +static int clk_branch_toggle(const struct clk_hw *hw, bool en) +{ + struct clk_branch *br = to_clk_branch(hw); + unsigned long flags; + u32 val; + + spin_lock_irqsave(br->lock, flags); + + val = readl_relaxed(br->ctl_reg); + if (en) + val |= BIT(br->ctl_bit); + else + val &= ~BIT(br->ctl_bit); + writel(val, br->ctl_reg); + + spin_unlock_irqrestore(br->lock, flags); + + return clk_branch_wait(br, en); +} + +static int clk_branch_enable(struct clk_hw *hw) +{ + return clk_branch_toggle(hw, true); +} + +static void clk_branch_disable(struct clk_hw *hw) +{ + clk_branch_toggle(hw, false); +} + +static int clk_branch_is_enabled(struct clk_hw *hw) +{ + struct clk_branch *br = to_clk_branch(hw); + u32 val; + + val = readl_relaxed(br->ctl_reg); + val &= BIT(br->ctl_bit); + + return val ? 1 : 0; +} + +static const struct clk_ops clk_branch_ops = { + .enable = clk_branch_enable, + .is_enabled = clk_branch_is_enabled, + .disable = clk_branch_disable, +}; + +struct clk *branch_clk_register(struct device *dev, struct branch_desc *desc, + spinlock_t *lock, struct clk_init_data *init) +{ + struct clk_branch *b; + + b = devm_kzalloc(dev, sizeof(*b), GFP_KERNEL); + if (!b) + return ERR_PTR(-ENOMEM); + + b->ctl_reg = desc->base + desc->ctl_reg; + b->halt_reg = desc->base + desc->halt_reg; + b->ctl_bit = desc->ctl_bit; + b->halt_bit = desc->halt_bit; + b->halt_check = desc->halt_check; + b->lock = lock; + + init->ops = &clk_branch_ops; + init->flags |= CLK_SET_RATE_PARENT; + b->hw.init = init; + + return devm_clk_register(dev, &b->hw); +} + +struct clk *branch_hg_clk_register(struct device *dev, struct branch_desc *desc, + spinlock_t *lock, struct clk_init_data *init) +{ + struct clk_branch *b; + + b = devm_kzalloc(dev, sizeof(*b), GFP_KERNEL); + if (!b) + return ERR_PTR(-ENOMEM); + + b->ctl_reg = desc->base + desc->ctl_reg; + b->halt_reg = desc->base + desc->halt_reg; + b->hwcg_reg = desc->base + desc->hwcg_reg; + b->ctl_bit = desc->ctl_bit; + b->halt_bit = desc->halt_bit; + b->halt_check = desc->halt_check; + b->lock = lock; + + init->ops = &clk_branch_ops; + init->flags |= CLK_SET_RATE_PARENT; + b->hw.init = init; + + return devm_clk_register(dev, &b->hw); +} diff --git a/drivers/clk/msm/clk-branch.h b/drivers/clk/msm/clk-branch.h new file mode 100644 index 0000000..bcb7345 --- /dev/null +++ b/drivers/clk/msm/clk-branch.h @@ -0,0 +1,48 @@ +/* + * Copyright (c) 2013, The Linux Foundation. All rights reserved. + * + * This software is licensed under the terms of the GNU General Public + * License version 2, as published by the Free Software Foundation, and + * may be copied, distributed, and modified under those terms. + * + * 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. + */ + +#ifndef __MSM_CLK_BRANCH_H__ +#define __MSM_CLK_BRANCH_H__ + +#include + +struct device; +struct clk; +struct clk_init_data; + +struct branch_desc { + void __iomem *base; + u32 ctl_reg; + u32 hwcg_reg; + u32 halt_reg; + + u8 ctl_bit; + u8 hwcg_bit; + u8 halt_bit; + u8 halt_check; +#define BRANCH_VOTED BIT(7) /* Delay on disable */ +#define BRANCH_HALT 0 /* pol: 1 = halt */ +#define BRANCH_HALT_VOTED (BRANCH_HALT | BRANCH_VOTED) +#define BRANCH_HALT_ENABLE 1 /* pol: 0 = halt */ +#define BRANCH_HALT_ENABLE_VOTED (BRANCH_HALT_ENABLE | BRANCH_VOTED) +#define BRANCH_HALT_DELAY 2 /* No bit to check; just delay */ +}; + +extern struct clk *branch_clk_register(struct device *dev, + struct branch_desc *desc, spinlock_t *lock, + struct clk_init_data *init); +extern struct clk *branch_hg_clk_register(struct device *dev, + struct branch_desc *desc, spinlock_t *lock, + struct clk_init_data *init); + +#endif -- The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/