clk: at91: Add clock driver

The patch is referred to at91 clock driver of Linux, to make
the clock node descriptions in DT aligned with the Linux's.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 76 insertions, 0 deletions

diff --git a/drivers/clk/at91/clk-system.c b/drivers/clk/at91/clk-system.c
new file mode 100644
index 0000000000..fa80bade7a
--- /dev/null
+++ b/drivers/clk/at91/clk-system.c
@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2016 Atmel Corporation
+ *               Wenyou.Yang <wenyou.yang@atmel.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <clk-uclass.h>
+#include <dm/device.h>
+#include <linux/io.h>
+#include <mach/at91_pmc.h>
+#include "pmc.h"
+
+#define SYSTEM_MAX_ID		31
+
+static inline int is_pck(int id)
+{
+	return (id >= 8) && (id <= 15);
+}
+
+static int at91_system_clk_enable(struct clk *clk)
+{
+	struct pmc_platdata *plat = dev_get_platdata(clk->dev);
+	struct at91_pmc *pmc = plat->reg_base;
+	u32 mask;
+
+	if (clk->id > SYSTEM_MAX_ID)
+		return -EINVAL;
+
+	mask = BIT(clk->id);
+
+	writel(mask, &pmc->scer);
+
+	/**
+	 * For the programmable clocks the Ready status in the PMC
+	 * status register should be checked after enabling.
+	 * For other clocks this is unnecessary.
+	 */
+	if (!is_pck(clk->id))
+		return 0;
+
+	while (!(readl(&pmc->sr) & mask))
+		;
+
+	return 0;
+}
+
+static struct clk_ops at91_system_clk_ops = {
+	.enable = at91_system_clk_enable,
+};
+
+static int at91_system_clk_bind(struct udevice *dev)
+{
+	return at91_pmc_clk_node_bind(dev);
+}
+
+static int at91_system_clk_probe(struct udevice *dev)
+{
+	return at91_pmc_core_probe(dev);
+}
+
+static const struct udevice_id at91_system_clk_match[] = {
+	{ .compatible = "atmel,at91rm9200-clk-system" },
+	{}
+};
+
+U_BOOT_DRIVER(at91_system_clk) = {
+	.name = "at91-system-clk",
+	.id = UCLASS_CLK,
+	.of_match = at91_system_clk_match,
+	.bind = at91_system_clk_bind,
+	.probe = at91_system_clk_probe,
+	.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
+	.ops = &at91_system_clk_ops,
+};