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authorLinus Torvalds <torvalds@linux-foundation.org>2014-01-24 06:45:38 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2014-01-24 06:45:38 +0400
commit9b6d351a75dae25430383b29a3764ae7921f6c47 (patch)
tree605b1ec9f90138553cb7efedf9dbb3df93bef3a8 /drivers/clk/shmobile/clk-mstp.c
parentdfd10e7ae60c6c1b24b5d601744b4fd1ecab2f31 (diff)
parent310c85476d5047f5ace4d1c527e1bbbc0c7ad672 (diff)
downloadlinux-9b6d351a75dae25430383b29a3764ae7921f6c47.tar.xz
Merge tag 'dt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC DT updates from Olof Johansson: "DT and DT-conversion-related changes for various ARM platforms. Most of these are to enable various devices on various boards, etc, and not necessarily worth enumerating. New boards and systems continue to come in as new devicetree files that don't require corresponding C changes any more, which is indicating that the system is starting to work fairly well. A few things worth pointing out: * ST Ericsson ux500 platforms have made the major push to move over to fully support the platform with DT * Renesas platforms continue their conversion over from legacy platform devices to DT-based for hardware description" * tag 'dt-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (327 commits) ARM: dts: SiRF: add pin group for USP0 with only RX or TX frame sync ARM: dts: SiRF: add lost usp1_uart_nostreamctrl pin group for atlas6 ARM: dts: sirf: add lost minigpsrtc device node ARM: dts: sirf: add clock, frequence-voltage table for CPU0 ARM: dts: sirf: add lost bus_width, clock and status for sdhci ARM: dts: sirf: add lost clocks for cphifbg ARM: dts: socfpga: add pl330 clock ARM: dts: socfpga: update L2 tag and data latency arm: sun7i: cubietruck: Enable the i2c controllers ARM: dts: add support for EXYNOS4412 based TINY4412 board ARM: dts: Add initial support for Arndale Octa board ARM: bcm2835: add USB controller to device tree ARM: dts: MSM8974: Add MMIO architected timer node ARM: dts: MSM8974: Add restart node ARM: dts: sun7i: external clock outputs ARM: dts: sun7i: Change 32768 Hz oscillator node name to clk@N style ARM: dts: sun7i: Add pin muxing options for clock outputs ARM: dts: sun7i: Add rtp controller node ARM: dts: sun5i: Add rtp controller node ARM: dts: sun4i: Add rtp controller node ...
Diffstat (limited to 'drivers/clk/shmobile/clk-mstp.c')
-rw-r--r--drivers/clk/shmobile/clk-mstp.c229
1 files changed, 229 insertions, 0 deletions
diff --git a/drivers/clk/shmobile/clk-mstp.c b/drivers/clk/shmobile/clk-mstp.c
new file mode 100644
index 000000000000..e576b60de20e
--- /dev/null
+++ b/drivers/clk/shmobile/clk-mstp.c
@@ -0,0 +1,229 @@
+/*
+ * R-Car MSTP clocks
+ *
+ * Copyright (C) 2013 Ideas On Board SPRL
+ *
+ * Contact: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/spinlock.h>
+
+/*
+ * MSTP clocks. We can't use standard gate clocks as we need to poll on the
+ * status register when enabling the clock.
+ */
+
+#define MSTP_MAX_CLOCKS 32
+
+/**
+ * struct mstp_clock_group - MSTP gating clocks group
+ *
+ * @data: clocks in this group
+ * @smstpcr: module stop control register
+ * @mstpsr: module stop status register (optional)
+ * @lock: protects writes to SMSTPCR
+ */
+struct mstp_clock_group {
+ struct clk_onecell_data data;
+ void __iomem *smstpcr;
+ void __iomem *mstpsr;
+ spinlock_t lock;
+};
+
+/**
+ * struct mstp_clock - MSTP gating clock
+ * @hw: handle between common and hardware-specific interfaces
+ * @bit_index: control bit index
+ * @group: MSTP clocks group
+ */
+struct mstp_clock {
+ struct clk_hw hw;
+ u32 bit_index;
+ struct mstp_clock_group *group;
+};
+
+#define to_mstp_clock(_hw) container_of(_hw, struct mstp_clock, hw)
+
+static int cpg_mstp_clock_endisable(struct clk_hw *hw, bool enable)
+{
+ struct mstp_clock *clock = to_mstp_clock(hw);
+ struct mstp_clock_group *group = clock->group;
+ u32 bitmask = BIT(clock->bit_index);
+ unsigned long flags;
+ unsigned int i;
+ u32 value;
+
+ spin_lock_irqsave(&group->lock, flags);
+
+ value = clk_readl(group->smstpcr);
+ if (enable)
+ value &= ~bitmask;
+ else
+ value |= bitmask;
+ clk_writel(value, group->smstpcr);
+
+ spin_unlock_irqrestore(&group->lock, flags);
+
+ if (!enable || !group->mstpsr)
+ return 0;
+
+ for (i = 1000; i > 0; --i) {
+ if (!(clk_readl(group->mstpsr) & bitmask))
+ break;
+ cpu_relax();
+ }
+
+ if (!i) {
+ pr_err("%s: failed to enable %p[%d]\n", __func__,
+ group->smstpcr, clock->bit_index);
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static int cpg_mstp_clock_enable(struct clk_hw *hw)
+{
+ return cpg_mstp_clock_endisable(hw, true);
+}
+
+static void cpg_mstp_clock_disable(struct clk_hw *hw)
+{
+ cpg_mstp_clock_endisable(hw, false);
+}
+
+static int cpg_mstp_clock_is_enabled(struct clk_hw *hw)
+{
+ struct mstp_clock *clock = to_mstp_clock(hw);
+ struct mstp_clock_group *group = clock->group;
+ u32 value;
+
+ if (group->mstpsr)
+ value = clk_readl(group->mstpsr);
+ else
+ value = clk_readl(group->smstpcr);
+
+ return !!(value & BIT(clock->bit_index));
+}
+
+static const struct clk_ops cpg_mstp_clock_ops = {
+ .enable = cpg_mstp_clock_enable,
+ .disable = cpg_mstp_clock_disable,
+ .is_enabled = cpg_mstp_clock_is_enabled,
+};
+
+static struct clk * __init
+cpg_mstp_clock_register(const char *name, const char *parent_name,
+ unsigned int index, struct mstp_clock_group *group)
+{
+ struct clk_init_data init;
+ struct mstp_clock *clock;
+ struct clk *clk;
+
+ clock = kzalloc(sizeof(*clock), GFP_KERNEL);
+ if (!clock) {
+ pr_err("%s: failed to allocate MSTP clock.\n", __func__);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ init.name = name;
+ init.ops = &cpg_mstp_clock_ops;
+ init.flags = CLK_IS_BASIC;
+ init.parent_names = &parent_name;
+ init.num_parents = 1;
+
+ clock->bit_index = index;
+ clock->group = group;
+ clock->hw.init = &init;
+
+ clk = clk_register(NULL, &clock->hw);
+
+ if (IS_ERR(clk))
+ kfree(clock);
+
+ return clk;
+}
+
+static void __init cpg_mstp_clocks_init(struct device_node *np)
+{
+ struct mstp_clock_group *group;
+ struct clk **clks;
+ unsigned int i;
+
+ group = kzalloc(sizeof(*group), GFP_KERNEL);
+ clks = kzalloc(MSTP_MAX_CLOCKS * sizeof(*clks), GFP_KERNEL);
+ if (group == NULL || clks == NULL) {
+ kfree(group);
+ kfree(clks);
+ pr_err("%s: failed to allocate group\n", __func__);
+ return;
+ }
+
+ spin_lock_init(&group->lock);
+ group->data.clks = clks;
+
+ group->smstpcr = of_iomap(np, 0);
+ group->mstpsr = of_iomap(np, 1);
+
+ if (group->smstpcr == NULL) {
+ pr_err("%s: failed to remap SMSTPCR\n", __func__);
+ kfree(group);
+ kfree(clks);
+ return;
+ }
+
+ for (i = 0; i < MSTP_MAX_CLOCKS; ++i) {
+ const char *parent_name;
+ const char *name;
+ u32 clkidx;
+ int ret;
+
+ /* Skip clocks with no name. */
+ ret = of_property_read_string_index(np, "clock-output-names",
+ i, &name);
+ if (ret < 0 || strlen(name) == 0)
+ continue;
+
+ parent_name = of_clk_get_parent_name(np, i);
+ ret = of_property_read_u32_index(np, "renesas,clock-indices", i,
+ &clkidx);
+ if (parent_name == NULL || ret < 0)
+ break;
+
+ if (clkidx >= MSTP_MAX_CLOCKS) {
+ pr_err("%s: invalid clock %s %s index %u)\n",
+ __func__, np->name, name, clkidx);
+ continue;
+ }
+
+ clks[clkidx] = cpg_mstp_clock_register(name, parent_name, i,
+ group);
+ if (!IS_ERR(clks[clkidx])) {
+ group->data.clk_num = max(group->data.clk_num, clkidx);
+ /*
+ * Register a clkdev to let board code retrieve the
+ * clock by name and register aliases for non-DT
+ * devices.
+ *
+ * FIXME: Remove this when all devices that require a
+ * clock will be instantiated from DT.
+ */
+ clk_register_clkdev(clks[clkidx], name, NULL);
+ } else {
+ pr_err("%s: failed to register %s %s clock (%ld)\n",
+ __func__, np->name, name, PTR_ERR(clks[clkidx]));
+ }
+ }
+
+ of_clk_add_provider(np, of_clk_src_onecell_get, &group->data);
+}
+CLK_OF_DECLARE(cpg_mstp_clks, "renesas,cpg-mstp-clocks", cpg_mstp_clocks_init);