[v2,1/4] clk: mvebu: Add Core Divider clock

Message ID	1380224130-11868-2-git-send-email-ezequiel.garcia@free-electrons.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> To: <linux-arm-kernel@lists.infradead.org> Subject: [PATCH v2 1/4] clk: mvebu: Add Core Divider clock Date: Thu, 26 Sep 2013 16:35:27 -0300 Message-Id: <1380224130-11868-2-git-send-email-ezequiel.garcia@free-electrons.com> In-Reply-To: <1380224130-11868-1-git-send-email-ezequiel.garcia@free-electrons.com> References: <1380224130-11868-1-git-send-email-ezequiel.garcia@free-electrons.com> Cc: Lior Amsalem <alior@marvell.com>, Andrew Lunn <andrew@lunn.ch>, Mike Turquette <mturquette@linaro.org>, Jason Cooper <jason@lakedaemon.net>, Tawfik Bayouk <tawfik@marvell.com>, Ezequiel Garcia <ezequiel.garcia@free-electrons.com>, Gregory Clement <gregory.clement@free-electrons.com>, Thomas Petazzoni <thomas.petazzoni@free-electrons.com>, Emilio Lopez <elopez93@gmail.com> Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/drivers/clk/mvebu/Kconfig b/drivers/clk/mvebu/Kconfig index 0b0f3e7..c339b82 100644 --- a/drivers/clk/mvebu/Kconfig +++ b/drivers/clk/mvebu/Kconfig @@ -4,15 +4,20 @@ config MVEBU_CLK_COMMON config MVEBU_CLK_CPU bool +config MVEBU_CLK_COREDIV + bool + config ARMADA_370_CLK bool select MVEBU_CLK_COMMON select MVEBU_CLK_CPU + select MVEBU_CLK_COREDIV config ARMADA_XP_CLK bool select MVEBU_CLK_COMMON select MVEBU_CLK_CPU + select MVEBU_CLK_COREDIV config DOVE_CLK bool diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile index 1c7e70c..21bbfb4 100644 --- a/drivers/clk/mvebu/Makefile +++ b/drivers/clk/mvebu/Makefile @@ -1,5 +1,6 @@ obj-$(CONFIG_MVEBU_CLK_COMMON) += common.o obj-$(CONFIG_MVEBU_CLK_CPU) += clk-cpu.o +obj-$(CONFIG_MVEBU_CLK_COREDIV) += clk-corediv.o obj-$(CONFIG_ARMADA_370_CLK) += armada-370.o obj-$(CONFIG_ARMADA_XP_CLK) += armada-xp.o diff --git a/drivers/clk/mvebu/clk-corediv.c b/drivers/clk/mvebu/clk-corediv.c new file mode 100644 index 0000000..7162615 --- /dev/null +++ b/drivers/clk/mvebu/clk-corediv.c @@ -0,0 +1,223 @@ +/* + * MVEBU Core divider clock + * + * Copyright (C) 2013 Marvell + * + * Ezequiel Garcia <ezequiel.garcia@free-electrons.com> + * + * 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 <linux/kernel.h> +#include <linux/clk-provider.h> +#include <linux/of_address.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include "common.h" + +#define CORE_CLK_DIV_RATIO_MASK 0xff +#define CORE_CLK_DIV_RATIO_RELOAD BIT(8) +#define CORE_CLK_DIV_ENABLE_OFFSET 24 +#define CORE_CLK_DIV_RATIO_OFFSET 0x8 + +struct clk_corediv_desc { + unsigned int mask; + unsigned int offset; + unsigned int fieldbit; +}; + +struct clk_corediv { + struct clk_hw hw; + void __iomem *reg; + struct clk_corediv_desc desc; + spinlock_t lock; +}; + +static struct clk_onecell_data clk_data; + +static const struct clk_corediv_desc mvebu_corediv_desc[] __initconst = { + { .mask = 0x3f, .offset = 8, .fieldbit = 1 }, /* NAND clock */ +}; + +#define to_corediv_clk(p) container_of(p, struct clk_corediv, hw) + +static int clk_corediv_is_enabled(struct clk_hw *hwclk) +{ + struct clk_corediv *corediv = to_corediv_clk(hwclk); + struct clk_corediv_desc *desc = &corediv->desc; + u32 enable_mask = BIT(desc->fieldbit) << CORE_CLK_DIV_ENABLE_OFFSET; + + return !!(readl(corediv->reg) & enable_mask); +} + +static int clk_corediv_enable(struct clk_hw *hwclk) +{ + struct clk_corediv *corediv = to_corediv_clk(hwclk); + struct clk_corediv_desc *desc = &corediv->desc; + unsigned long flags = 0; + u32 reg; + + spin_lock_irqsave(&corediv->lock, flags); + + reg = readl(corediv->reg); + reg |= (BIT(desc->fieldbit) << CORE_CLK_DIV_ENABLE_OFFSET); + writel(reg, corediv->reg); + + spin_unlock_irqrestore(&corediv->lock, flags); + + return 0; +} + +static void clk_corediv_disable(struct clk_hw *hwclk) +{ + struct clk_corediv *corediv = to_corediv_clk(hwclk); + struct clk_corediv_desc *desc = &corediv->desc; + unsigned long flags = 0; + u32 reg; + + spin_lock_irqsave(&corediv->lock, flags); + + reg = readl(corediv->reg); + reg &= ~(BIT(desc->fieldbit) << CORE_CLK_DIV_ENABLE_OFFSET); + writel(reg, corediv->reg); + + spin_unlock_irqrestore(&corediv->lock, flags); +} + +static unsigned long clk_corediv_recalc_rate(struct clk_hw *hwclk, + unsigned long parent_rate) +{ + struct clk_corediv *corediv = to_corediv_clk(hwclk); + struct clk_corediv_desc *desc = &corediv->desc; + u32 reg, div; + + reg = readl(corediv->reg + CORE_CLK_DIV_RATIO_OFFSET); + div = (reg >> desc->offset) & desc->mask; + return parent_rate / div; +} + +static long clk_corediv_round_rate(struct clk_hw *hwclk, unsigned long rate, + unsigned long *parent_rate) +{ + /* Valid ratio are 1:4, 1:5, 1:6 and 1:8 */ + u32 div; + + div = *parent_rate / rate; + if (div < 4) + div = 4; + else if (div > 6) + div = 8; + + return *parent_rate / div; +} + +static int clk_corediv_set_rate(struct clk_hw *hwclk, unsigned long rate, + unsigned long parent_rate) +{ + struct clk_corediv *corediv = to_corediv_clk(hwclk); + struct clk_corediv_desc *desc = &corediv->desc; + unsigned long flags = 0; + u32 reg, div; + + div = parent_rate / rate; + + spin_lock_irqsave(&corediv->lock, flags); + + /* Write new divider to the divider ratio register */ + reg = readl(corediv->reg + CORE_CLK_DIV_RATIO_OFFSET); + reg &= ~(desc->mask << desc->offset); + reg |= (div & desc->mask) << desc->offset; + writel(reg, corediv->reg + CORE_CLK_DIV_RATIO_OFFSET); + + /* Set reload-force for this clock */ + reg = readl(corediv->reg) | BIT(desc->fieldbit); + writel(reg, corediv->reg); + + /* Now trigger the clock update */ + reg = readl(corediv->reg) | CORE_CLK_DIV_RATIO_RELOAD; + writel(reg, corediv->reg); + + /* + * Wait for clocks to settle down, and then clear all the + * ratios request and the reload request. + */ + udelay(1000); + reg &= ~(CORE_CLK_DIV_RATIO_MASK | CORE_CLK_DIV_RATIO_RELOAD); + writel(reg, corediv->reg); + udelay(1000); + + spin_unlock_irqrestore(&corediv->lock, flags); + + return 0; +} + +static const struct clk_ops corediv_ops = { + .enable = clk_corediv_enable, + .disable = clk_corediv_disable, + .is_enabled = clk_corediv_is_enabled, + .recalc_rate = clk_corediv_recalc_rate, + .round_rate = clk_corediv_round_rate, + .set_rate = clk_corediv_set_rate, +}; + +static void __init mvebu_corediv_clk_init(struct device_node *node) +{ + struct clk_init_data init; + struct clk_corediv *corediv; + struct clk **clks; + void __iomem *base; + const char *parent_name; + const char *clk_name; + int i; + + base = of_iomap(node, 0); + if (WARN_ON(!base)) + return; + + parent_name = of_clk_get_parent_name(node, 0); + + clk_data.clk_num = ARRAY_SIZE(mvebu_corediv_desc); + + /* clks holds the clock array */ + clks = kcalloc(clk_data.clk_num, sizeof(struct clk *), + GFP_KERNEL); + if (WARN_ON(!clks)) + goto err_unmap; + /* corediv holds the clock specific array */ + corediv = kcalloc(clk_data.clk_num, sizeof(struct clk_corediv), + GFP_KERNEL); + if (WARN_ON(!corediv)) + goto err_free_clks; + + spin_lock_init(&corediv->lock); + + for (i = 0; i < clk_data.clk_num; i++) { + of_property_read_string_index(node, "clock-output-names", + i, &clk_name); + init.num_parents = 1; + init.parent_names = &parent_name; + init.name = clk_name; + init.ops = &corediv_ops; + init.flags = 0; + + corediv[i].desc = mvebu_corediv_desc[i]; + corediv[i].reg = base; + corediv[i].hw.init = &init; + + clks[i] = clk_register(NULL, &corediv[i].hw); + WARN_ON(IS_ERR(clks[i])); + } + + clk_data.clks = clks; + of_clk_add_provider(node, of_clk_src_onecell_get, &clk_data); + return; + +err_free_clks: + kfree(clks); +err_unmap: + iounmap(base); +} +CLK_OF_DECLARE(mvebu_corediv_clk, "marvell,armada-370-corediv-clock", + mvebu_corediv_clk_init);

[v2,1/4] clk: mvebu: Add Core Divider clock

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