[PATCH 08/10] clk: mvebu Add the time base generator clocks for Armada 3700

Gregory CLEMENT
2016-06-10T13:25:11Z

These clocks are children of the xtal clock and each one can be selected
as a source for the peripheral clocks.

According to the datasheet it should be possible to modify their rate,
but currently it is not supported.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
---
drivers/clk/mvebu/Makefile | 1 +
drivers/clk/mvebu/armada-37xx-tbg.c | 172 ++++++++++++++++++++++++++++++++++++
2 files changed, 173 insertions(+)
create mode 100644 drivers/clk/mvebu/armada-37xx-tbg.c

diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
index 4257a36d0219..72e3512a9d4a 100644
--- a/drivers/clk/mvebu/Makefile
+++ b/drivers/clk/mvebu/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_ARMADA_375_CLK) += armada-375.o
obj-$(CONFIG_ARMADA_38X_CLK) += armada-38x.o
obj-$(CONFIG_ARMADA_39X_CLK) += armada-39x.o
obj-$(CONFIG_ARMADA_37XX_CLK) += armada-37xx-xtal.o
+obj-$(CONFIG_ARMADA_37XX_CLK) += armada-37xx-tbg.o
obj-$(CONFIG_ARMADA_XP_CLK) += armada-xp.o
obj-$(CONFIG_ARMADA_AP806_SYSCON) += ap806-system-controller.o
obj-$(CONFIG_ARMADA_CP110_SYSCON) += cp110-system-controller.o
diff --git a/drivers/clk/mvebu/armada-37xx-tbg.c b/drivers/clk/mvebu/armada-37xx-tbg.c
new file mode 100644
index 000000000000..e9a331b85a78
--- /dev/null
+++ b/drivers/clk/mvebu/armada-37xx-tbg.c
@@ -0,0 +1,172 @@
+/*
+ * Marvell Armada 37xx SoC Time Base Generator clocks
+ *
+ * Copyright (C) 2016 Marvell
+ *
+ * Gregory CLEMENT <gregory.clement@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/clk-provider.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#define NUM_TBG 4
+
+#define TBG_CTRL0 0x4
+#define TBG_CTRL1 0x8
+#define TBG_CTRL7 0x20
+#define TBG_CTRL8 0x30
+
+#define TBG_DIV_MASK 0x1FF
+
+#define TBG_A_REFDIV 0
+#define TBG_B_REFDIV 16
+
+#define TBG_A_FBDIV 2
+#define TBG_B_FBDIV 18
+
+#define TBG_A_VCODIV_SE 0
+#define TBG_B_VCODIV_SE 16
+
+#define TBG_A_VCODIV_DIFF 1
+#define TBG_B_VCODIV_DIFF 17
+
+struct tbg_def {
+ char *name;
+ u32 refdiv_offset;
+ u32 fbdiv_offset;
+ u32 vcodiv_reg;
+ u32 vcodiv_offset;
+};
+
+struct tbg_def tbg[NUM_TBG] = {
+ {"TBG-A-P", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL8, TBG_A_VCODIV_DIFF},
+ {"TBG-B-P", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL8, TBG_B_VCODIV_DIFF},
+ {"TBG-A-S", TBG_A_REFDIV, TBG_A_FBDIV, TBG_CTRL1, TBG_A_VCODIV_SE},
+ {"TBG-B-S", TBG_B_REFDIV, TBG_B_FBDIV, TBG_CTRL1, TBG_B_VCODIV_SE},
+};
+
+static struct clk_onecell_data clk_tbg_data;
+
+unsigned int tbg_get_mult(void __iomem *reg, struct tbg_def *ptbg)
+{
+ u32 val;
+
+ val = readl(reg + TBG_CTRL0);
+
+ return ((val >> ptbg->fbdiv_offset) & TBG_DIV_MASK) << 2;
+}
+
+unsigned int tbg_get_div(void __iomem *reg, struct tbg_def *ptbg)
+{
+ u32 val;
+ unsigned int div;
+
+ val = readl(reg + TBG_CTRL7);
+
+ div = (val >> ptbg->refdiv_offset) & TBG_DIV_MASK;
+ if (div == 0)
+ div = 1;
+ val = readl(reg + ptbg->vcodiv_reg);
+
+ div *= 1 << ((val >> ptbg->vcodiv_offset) & TBG_DIV_MASK);
+
+ return div;
+}
+
+
+static int armada_3700_tbg_clock_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct device *dev = &pdev->dev;
+ const char *parent_name;
+ struct resource *res;
+ struct clk *parent;
+ void __iomem *reg;
+ int i, ret;
+
+ parent = of_clk_get(np, 0);
+ if (IS_ERR(parent)) {
+ dev_err(dev, "Could get the clock parent\n");
+ return -EINVAL;
+ }
+ parent_name = __clk_get_name(parent);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ reg = devm_ioremap_resource(dev, res);
+ if (IS_ERR(reg)) {
+ dev_err(dev, "Could not map the tbg clock registers\n");
+ ret = PTR_ERR(reg);
+ goto put_clk;
+ }
+
+ clk_tbg_data.clk_num = NUM_TBG;
+ clk_tbg_data.clks = devm_kcalloc(dev, clk_tbg_data.clk_num,
+ sizeof(struct clk *), GFP_KERNEL);
+ if (!clk_tbg_data.clks) {
+ ret = -ENOMEM;
+ goto put_clk;
+ }
+
+ for (i = 0; i < NUM_TBG; i++) {
+ const char *name;
+ unsigned int mult, div;
+
+ name = tbg[i].name;
+ mult = tbg_get_mult(reg, &tbg[i]);
+ div = tbg_get_div(reg, &tbg[i]);
+ clk_tbg_data.clks[i] = clk_register_fixed_factor(NULL, name,
+ parent_name, 0, mult, div);
+ if (IS_ERR(clk_tbg_data.clks[i]))
+ dev_err(dev, "Can't register TBG clock %s\n", name);
+ }
+
+ of_clk_add_provider(np, of_clk_src_onecell_get, &clk_tbg_data);
+
+ return 0;
+
+put_clk:
+ clk_put(parent);
+ return ret;
+}
+
+static int armada_3700_tbg_clock_remove(struct platform_device *pdev)
+{
+ int i;
+
+ of_clk_del_provider(pdev->dev.of_node);
+ for (i = 0; i < clk_tbg_data.clk_num; i++)
+ clk_unregister_fixed_factor(clk_tbg_data.clks[i]);
+
+ return 0;
+}
+
+static const struct of_device_id armada_3700_tbg_clock_of_match[] = {
+ { .compatible = "marvell,armada-3700-tbg-clock", },
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, armada_3700_tbg_clock_of_match);
+
+static struct platform_driver armada_3700_tbg_clock_driver = {
+ .probe = armada_3700_tbg_clock_probe,
+ .remove = armada_3700_tbg_clock_remove,
+ .driver = {
+ .name = "marvell-armada-3700-tbg-clock",
+ .of_match_table = armada_3700_tbg_clock_of_match,
+ },
+};
+
+module_platform_driver(armada_3700_tbg_clock_driver);
+
+MODULE_AUTHOR("Gregory CLEMENT <gregory.clement@free-electrons.com>");
+MODULE_DESCRIPTION("Marvell Armada 37xx SoC Time Base Generator driver");
+MODULE_LICENSE("GPL v2");
--
2.5.0