clk: mvebu: Add the xtal clock for Armada 3700 SoC

This clock is the parent of all the Armada 3700 clocks. It is a fixed
rate clock which depends on the gpio configuration read when resetting
the SoC.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

3 files changed, 95 insertions, 0 deletions

diff --git a/drivers/clk/mvebu/Kconfig b/drivers/clk/mvebu/Kconfig
index 3165da77d525..fddc8ac5faff 100644
--- a/drivers/clk/mvebu/Kconfig
+++ b/drivers/clk/mvebu/Kconfig
@@ -24,6 +24,9 @@ config ARMADA_39X_CLK
         bool
         select MVEBU_CLK_COMMON
 
+config ARMADA_37XX_CLK
+       bool
+
 config ARMADA_XP_CLK
         bool
         select MVEBU_CLK_COMMON
diff --git a/drivers/clk/mvebu/Makefile b/drivers/clk/mvebu/Makefile
index 7172ef65693d..4257a36d0219 100644
--- a/drivers/clk/mvebu/Makefile
+++ b/drivers/clk/mvebu/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_ARMADA_370_CLK)	+= armada-370.o
 obj-$(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_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-xtal.c b/drivers/clk/mvebu/armada-37xx-xtal.c
new file mode 100644
index 000000000000..612d65ede10a
--- /dev/null
+++ b/drivers/clk/mvebu/armada-37xx-xtal.c
@@ -0,0 +1,91 @@
+/*
+ * Marvell Armada 37xx SoC xtal 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/mfd/syscon.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define NB_GPIO1_LATCH  0xC
+#define XTAL_MODE           BIT(31)
+
+static int armada_3700_xtal_clock_probe(struct platform_device *pdev)
+{
+        struct device_node *np = pdev->dev.of_node;
+        const char *xtal_name = "xtal";
+        struct device_node *parent;
+        struct regmap *regmap;
+        struct clk_hw *xtal_hw;
+        unsigned int rate;
+        u32 reg;
+        int ret;
+
+        xtal_hw = devm_kzalloc(&pdev->dev, sizeof(*xtal_hw), GFP_KERNEL);
+        if (!xtal_hw)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, xtal_hw);
+
+        parent = np->parent;
+        if (!parent) {
+                dev_err(&pdev->dev, "no parent\n");
+                return -ENODEV;
+        }
+
+        regmap = syscon_node_to_regmap(parent);
+        if (IS_ERR(regmap)) {
+                dev_err(&pdev->dev, "cannot get regmap\n");
+                return PTR_ERR(regmap);
+        }
+
+        ret = regmap_read(regmap, NB_GPIO1_LATCH, &reg);
+        if (ret) {
+                dev_err(&pdev->dev, "cannot read from regmap\n");
+                return ret;
+        }
+
+        if (reg & XTAL_MODE)
+                rate = 40000000;
+        else
+                rate = 25000000;
+
+        of_property_read_string_index(np, "clock-output-names", 0, &xtal_name);
+        xtal_hw = clk_hw_register_fixed_rate(NULL, xtal_name, NULL, 0, rate);
+        if (IS_ERR(xtal_hw))
+                return PTR_ERR(xtal_hw);
+        ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, xtal_hw);
+
+        return ret;
+}
+
+static int armada_3700_xtal_clock_remove(struct platform_device *pdev)
+{
+        of_clk_del_provider(pdev->dev.of_node);
+
+        return 0;
+}
+
+static const struct of_device_id armada_3700_xtal_clock_of_match[] = {
+        { .compatible = "marvell,armada-3700-xtal-clock", },
+        { }
+};
+
+static struct platform_driver armada_3700_xtal_clock_driver = {
+        .probe = armada_3700_xtal_clock_probe,
+        .remove = armada_3700_xtal_clock_remove,
+        .driver         = {
+                .name   = "marvell-armada-3700-xtal-clock",
+                .of_match_table = armada_3700_xtal_clock_of_match,
+        },
+};
+
+builtin_platform_driver(armada_3700_xtal_clock_driver);