1 files changed, 114 insertions, 0 deletions
diff --git a/drivers/clk/imx/clk.c b/drivers/clk/imx/clk.c
new file mode 100644
index 000000000..9074e6974
--- /dev/null
+++ b/drivers/clk/imx/clk.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include "clk.h"
+
+DEFINE_SPINLOCK(imx_ccm_lock);
+
+void __init imx_check_clocks(struct clk *clks[], unsigned int count)
+{
+	unsigned i;
+
+	for (i = 0; i < count; i++)
+		if (IS_ERR(clks[i]))
+			pr_err("i.MX clk %u: register failed with %ld\n",
+			       i, PTR_ERR(clks[i]));
+}
+
+static struct clk * __init imx_obtain_fixed_clock_from_dt(const char *name)
+{
+	struct of_phandle_args phandle;
+	struct clk *clk = ERR_PTR(-ENODEV);
+	char *path;
+
+	path = kasprintf(GFP_KERNEL, "/clocks/%s", name);
+	if (!path)
+		return ERR_PTR(-ENOMEM);
+
+	phandle.np = of_find_node_by_path(path);
+	kfree(path);
+
+	if (phandle.np) {
+		clk = of_clk_get_from_provider(&phandle);
+		of_node_put(phandle.np);
+	}
+	return clk;
+}
+
+struct clk * __init imx_obtain_fixed_clock(
+			const char *name, unsigned long rate)
+{
+	struct clk *clk;
+
+	clk = imx_obtain_fixed_clock_from_dt(name);
+	if (IS_ERR(clk))
+		clk = imx_clk_fixed(name, rate);
+	return clk;
+}
+
+/*
+ * This fixups the register CCM_CSCMR1 write value.
+ * The write/read/divider values of the aclk_podf field
+ * of that register have the relationship described by
+ * the following table:
+ *
+ * write value       read value        divider
+ * 3b'000            3b'110            7
+ * 3b'001            3b'111            8
+ * 3b'010            3b'100            5
+ * 3b'011            3b'101            6
+ * 3b'100            3b'010            3
+ * 3b'101            3b'011            4
+ * 3b'110            3b'000            1
+ * 3b'111            3b'001            2(default)
+ *
+ * That's why we do the xor operation below.
+ */
+#define CSCMR1_FIXUP	0x00600000
+
+void imx_cscmr1_fixup(u32 *val)
+{
+	*val ^= CSCMR1_FIXUP;
+	return;
+}
+
+static int imx_keep_uart_clocks __initdata;
+static struct clk ** const *imx_uart_clocks __initdata;
+
+static int __init imx_keep_uart_clocks_param(char *str)
+{
+	imx_keep_uart_clocks = 1;
+
+	return 0;
+}
+__setup_param("earlycon", imx_keep_uart_earlycon,
+	      imx_keep_uart_clocks_param, 0);
+__setup_param("earlyprintk", imx_keep_uart_earlyprintk,
+	      imx_keep_uart_clocks_param, 0);
+
+void __init imx_register_uart_clocks(struct clk ** const clks[])
+{
+	if (imx_keep_uart_clocks) {
+		int i;
+
+		imx_uart_clocks = clks;
+		for (i = 0; imx_uart_clocks[i]; i++)
+			clk_prepare_enable(*imx_uart_clocks[i]);
+	}
+}
+
+static int __init imx_clk_disable_uart(void)
+{
+	if (imx_keep_uart_clocks && imx_uart_clocks) {
+		int i;
+
+		for (i = 0; imx_uart_clocks[i]; i++)
+			clk_disable_unprepare(*imx_uart_clocks[i]);
+	}
+
+	return 0;
+}
+late_initcall_sync(imx_clk_disable_uart);