| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <1430410206-4410-3-git-send-email-wens@csie.org>
Date: Fri, 1 May 2015 00:10:03 +0800
From: Chen-Yu Tsai <wens@...e.org>
To: Maxime Ripard <maxime.ripard@...e-electrons.com>,
Lee Jones <lee.jones@...aro.org>,
Mike Turquette <mturquette@...aro.org>,
Stephen Boyd <sboyd@...eaurora.org>
Cc: Chen-Yu Tsai <wens@...e.org>, linux-clk@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2 2/5] clk: sunxi: support the cpus (cpu special) clock on the Allwinner A80
The "cpus" clock is the clock for the embedded processor in the A80.
It is also part of the PRCM clock tree.
Signed-off-by: Chen-Yu Tsai <wens@...e.org>
---
Documentation/devicetree/bindings/clock/sunxi.txt | 1 +
drivers/clk/sunxi/Makefile | 2 +-
drivers/clk/sunxi/clk-sun9i-cpus.c | 243 ++++++++++++++++++++++
3 files changed, 245 insertions(+), 1 deletion(-)
create mode 100644 drivers/clk/sunxi/clk-sun9i-cpus.c
diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
index 2015b2beb957..c52735b0b924 100644
--- a/Documentation/devicetree/bindings/clock/sunxi.txt
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -27,6 +27,7 @@ Required properties:
"allwinner,sun5i-a10s-ahb-gates-clk" - for the AHB gates on A10s
"allwinner,sun7i-a20-ahb-gates-clk" - for the AHB gates on A20
"allwinner,sun6i-a31-ar100-clk" - for the AR100 on A31
+ "allwinner,sun9i-a80-cpus-clk" - for the CPUS on A80
"allwinner,sun6i-a31-ahb1-clk" - for the AHB1 clock on A31
"allwinner,sun6i-a31-ahb1-gates-clk" - for the AHB1 gates on A31
"allwinner,sun8i-a23-ahb1-gates-clk" - for the AHB1 gates on A23
diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
index 058f273d6154..f0f33131b048 100644
--- a/drivers/clk/sunxi/Makefile
+++ b/drivers/clk/sunxi/Makefile
@@ -13,4 +13,4 @@ obj-y += clk-usb.o
obj-$(CONFIG_MFD_SUN6I_PRCM) += \
clk-sun6i-ar100.o clk-sun6i-apb0.o clk-sun6i-apb0-gates.o \
- clk-sun8i-apb0.o
+ clk-sun8i-apb0.o clk-sun9i-cpus.o
diff --git a/drivers/clk/sunxi/clk-sun9i-cpus.c b/drivers/clk/sunxi/clk-sun9i-cpus.c
new file mode 100644
index 000000000000..1ec61ccf8cbf
--- /dev/null
+++ b/drivers/clk/sunxi/clk-sun9i-cpus.c
@@ -0,0 +1,243 @@
+/*
+ * Copyright (C) 2015 Chen-Yu Tsai
+ *
+ * Chen-Yu Tsai <wens@...e.org>
+ *
+ * Allwinner A80 CPUS clock driver
+ *
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+static DEFINE_SPINLOCK(sun9i_a80_cpus_lock);
+
+/**
+ * sun9i_a80_cpus_clk_setup() - Setup function for a80 cpus composite clk
+ */
+
+#define SUN9I_CPUS_MAX_PARENTS 4
+#define SUN9I_CPUS_MUX_PARENT_PLL4 3
+#define SUN9I_CPUS_MUX_SHIFT 16
+/* un-shifted mask is what mux_clk expects */
+#define SUN9I_CPUS_MUX_MASK 0x3
+#define SUN9I_CPUS_MUX_GET_PARENT(reg) ((reg >> SUN9I_CPUS_MUX_SHIFT) & \
+ SUN9I_CPUS_MUX_MASK)
+
+#define SUN9I_CPUS_DIV_SHIFT 4
+#define SUN9I_CPUS_DIV_MASK (0x3 << SUN9I_CPUS_DIV_SHIFT)
+#define SUN9I_CPUS_DIV_GET(reg) ((reg & SUN9I_CPUS_DIV_MASK) >> \
+ SUN9I_CPUS_DIV_SHIFT)
+#define SUN9I_CPUS_DIV_SET(reg, div) ((reg & ~SUN9I_CPUS_DIV_MASK) | \
+ (div << SUN9I_CPUS_DIV_SHIFT))
+#define SUN9I_CPUS_PLL4_DIV_SHIFT 8
+#define SUN9I_CPUS_PLL4_DIV_MASK (0x1f << SUN9I_CPUS_PLL4_DIV_SHIFT)
+#define SUN9I_CPUS_PLL4_DIV_GET(reg) ((reg & SUN9I_CPUS_PLL4_DIV_MASK) >> \
+ SUN9I_CPUS_PLL4_DIV_SHIFT)
+#define SUN9I_CPUS_PLL4_DIV_SET(reg, div) ((reg & ~SUN9I_CPUS_PLL4_DIV_MASK) | \
+ (div << SUN9I_CPUS_PLL4_DIV_SHIFT))
+
+struct sun9i_a80_cpus_clk {
+ struct clk_hw hw;
+ void __iomem *reg;
+};
+
+#define to_sun9i_a80_cpus_clk(_hw) container_of(_hw, struct sun9i_a80_cpus_clk, hw)
+
+static unsigned long sun9i_a80_cpus_clk_recalc_rate(struct clk_hw *hw,
+ unsigned long parent_rate)
+{
+ struct sun9i_a80_cpus_clk *cpus = to_sun9i_a80_cpus_clk(hw);
+ unsigned long rate;
+ u32 reg;
+
+ /* Fetch the register value */
+ reg = readl(cpus->reg);
+
+ /* apply pre-divider first if parent is pll4 */
+ if (SUN9I_CPUS_MUX_GET_PARENT(reg) == SUN9I_CPUS_MUX_PARENT_PLL4)
+ parent_rate /= SUN9I_CPUS_PLL4_DIV_GET(reg) + 1;
+
+ /* clk divider */
+ rate = parent_rate / (SUN9I_CPUS_DIV_GET(reg) + 1);
+
+ return rate;
+}
+
+static long sun9i_a80_cpus_clk_round(unsigned long rate, u8 *divp, u8 *pre_divp,
+ u8 parent, unsigned long parent_rate)
+{
+ u8 div, pre_div = 1;
+
+ /*
+ * clock can only divide, so we will never be able to achieve
+ * frequencies higher than the parent frequency
+ */
+ if (parent_rate && rate > parent_rate)
+ rate = parent_rate;
+
+ div = DIV_ROUND_UP(parent_rate, rate);
+
+ /* calculate pre-divider if parent is pll4 */
+ if (parent == SUN9I_CPUS_MUX_PARENT_PLL4 && div > 4) {
+ /* pre-divider is 1 ~ 32 */
+ if (div < 32) {
+ pre_div = div;
+ div = 1;
+ } else if (div < 64) {
+ pre_div = DIV_ROUND_UP(div, 2);
+ div = 2;
+ } else if (div < 96) {
+ pre_div = DIV_ROUND_UP(div, 3);
+ div = 3;
+ } else {
+ pre_div = DIV_ROUND_UP(div, 4);
+ div = 4;
+ }
+ }
+
+ /* we were asked to pass back divider values */
+ if (divp) {
+ *divp = div - 1;
+ *pre_divp = pre_div - 1;
+ }
+
+ return parent_rate / pre_div / div;
+}
+
+static long sun9i_a80_cpus_clk_determine_rate(struct clk_hw *hw,
+ unsigned long rate,
+ unsigned long min_rate,
+ unsigned long max_rate,
+ unsigned long *best_parent_rate,
+ struct clk_hw **best_parent_clk)
+{
+ struct clk *clk = hw->clk, *parent, *best_parent = NULL;
+ int i, num_parents;
+ unsigned long parent_rate, best = 0, child_rate, best_child_rate = 0;
+
+ /* find the parent that can help provide the fastest rate <= rate */
+ num_parents = __clk_get_num_parents(clk);
+ for (i = 0; i < num_parents; i++) {
+ parent = clk_get_parent_by_index(clk, i);
+ if (!parent)
+ continue;
+ if (__clk_get_flags(clk) & CLK_SET_RATE_PARENT)
+ parent_rate = __clk_round_rate(parent, rate);
+ else
+ parent_rate = __clk_get_rate(parent);
+
+ child_rate = sun9i_a80_cpus_clk_round(rate, NULL, NULL, i,
+ parent_rate);
+
+ if (child_rate <= rate && child_rate > best_child_rate) {
+ best_parent = parent;
+ best = parent_rate;
+ best_child_rate = child_rate;
+ }
+ }
+
+ if (best_parent)
+ *best_parent_clk = __clk_get_hw(best_parent);
+ *best_parent_rate = best;
+
+ return best_child_rate;
+}
+
+static int sun9i_a80_cpus_clk_set_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long parent_rate)
+{
+ struct sun9i_a80_cpus_clk *cpus = to_sun9i_a80_cpus_clk(hw);
+ unsigned long flags;
+ u8 div, pre_div, parent;
+ u32 reg;
+
+ spin_lock_irqsave(&sun9i_a80_cpus_lock, flags);
+
+ reg = readl(cpus->reg);
+
+ /* need to know which parent is used to apply pre-divider */
+ parent = SUN9I_CPUS_MUX_GET_PARENT(reg);
+ sun9i_a80_cpus_clk_round(rate, &div, &pre_div, parent, parent_rate);
+
+ reg = SUN9I_CPUS_DIV_SET(reg, div);
+ reg = SUN9I_CPUS_PLL4_DIV_SET(reg, pre_div);
+ writel(reg, cpus->reg);
+
+ spin_unlock_irqrestore(&sun9i_a80_cpus_lock, flags);
+
+ return 0;
+}
+
+static const struct clk_ops sun9i_a80_cpus_clk_ops = {
+ .determine_rate = sun9i_a80_cpus_clk_determine_rate,
+ .recalc_rate = sun9i_a80_cpus_clk_recalc_rate,
+ .set_rate = sun9i_a80_cpus_clk_set_rate,
+};
+
+static int sun9i_a80_cpus_clk_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ const char *clk_name = np->name;
+ const char *parents[SUN9I_CPUS_MAX_PARENTS];
+ struct resource *r;
+ struct sun9i_a80_cpus_clk *cpus;
+ struct clk_mux *mux;
+ struct clk *clk;
+ int i = 0;
+
+ cpus = devm_kzalloc(&pdev->dev, sizeof(*cpus), GFP_KERNEL);
+ if (!cpus)
+ return -ENOMEM;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ cpus->reg = devm_ioremap_resource(&pdev->dev, r);
+ if (IS_ERR(cpus->reg))
+ return PTR_ERR(cpus->reg);
+
+ /* we have a mux, we will have >1 parents */
+ while (i < SUN9I_CPUS_MAX_PARENTS &&
+ (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
+ i++;
+
+ of_property_read_string(np, "clock-output-names", &clk_name);
+
+ mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ /* set up clock properties */
+ mux->reg = cpus->reg;
+ mux->shift = SUN9I_CPUS_MUX_SHIFT;
+ mux->mask = SUN9I_CPUS_MUX_MASK;
+ mux->lock = &sun9i_a80_cpus_lock;
+
+ clk = clk_register_composite(NULL, clk_name, parents, i,
+ &mux->hw, &clk_mux_ops,
+ &cpus->hw, &sun9i_a80_cpus_clk_ops,
+ NULL, NULL, 0);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ return of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static const struct of_device_id sun9i_a80_cpus_clk_dt_ids[] = {
+ { .compatible = "allwinner,sun9i-a80-cpus-clk" },
+ { /* sentinel */ }
+};
+
+static struct platform_driver sun9i_a80_cpus_clk_driver = {
+ .driver = {
+ .name = "sun9i-a80-cpus-clk",
+ .of_match_table = sun9i_a80_cpus_clk_dt_ids,
+ },
+ .probe = sun9i_a80_cpus_clk_probe,
+};
+module_platform_driver(sun9i_a80_cpus_clk_driver);
+
+MODULE_AUTHOR("Chen-Yu Tsai <wens@...e.org>");
+MODULE_DESCRIPTION("Allwinner A80 CPUS Clock Driver");
+MODULE_LICENSE("GPL v2");
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists