aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/mach-omap2/clkt2xxx_apll.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-omap2/clkt2xxx_apll.c')
-rw-r--r--arch/arm/mach-omap2/clkt2xxx_apll.c122
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/clkt2xxx_apll.c b/arch/arm/mach-omap2/clkt2xxx_apll.c
new file mode 100644
index 00000000000..43d7246ce33
--- /dev/null
+++ b/arch/arm/mach-omap2/clkt2xxx_apll.c
@@ -0,0 +1,122 @@
+/*
+ * OMAP2xxx APLL clock control functions
+ *
+ * Copyright (C) 2005-2008 Texas Instruments, Inc.
+ * Copyright (C) 2004-2010 Nokia Corporation
+ *
+ * Contacts:
+ * Richard Woodruff <r-woodruff2@ti.com>
+ * Paul Walmsley
+ *
+ * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
+ * Gordon McNutt and RidgeRun, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <plat/clock.h>
+#include <plat/prcm.h>
+
+#include "clock.h"
+#include "clock2xxx.h"
+#include "cm.h"
+#include "cm-regbits-24xx.h"
+
+/* CM_CLKEN_PLL.EN_{54,96}M_PLL options (24XX) */
+#define EN_APLL_STOPPED 0
+#define EN_APLL_LOCKED 3
+
+/* CM_CLKSEL1_PLL.APLLS_CLKIN options (24XX) */
+#define APLLS_CLKIN_19_2MHZ 0
+#define APLLS_CLKIN_13MHZ 2
+#define APLLS_CLKIN_12MHZ 3
+
+void __iomem *cm_idlest_pll;
+
+/* Private functions */
+
+/* Enable an APLL if off */
+static int omap2_clk_apll_enable(struct clk *clk, u32 status_mask)
+{
+ u32 cval, apll_mask;
+
+ apll_mask = EN_APLL_LOCKED << clk->enable_bit;
+
+ cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
+
+ if ((cval & apll_mask) == apll_mask)
+ return 0; /* apll already enabled */
+
+ cval &= ~apll_mask;
+ cval |= apll_mask;
+ cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
+
+ omap2_cm_wait_idlest(cm_idlest_pll, status_mask,
+ OMAP24XX_CM_IDLEST_VAL, clk->name);
+
+ /*
+ * REVISIT: Should we return an error code if omap2_wait_clock_ready()
+ * fails?
+ */
+ return 0;
+}
+
+static int omap2_clk_apll96_enable(struct clk *clk)
+{
+ return omap2_clk_apll_enable(clk, OMAP24XX_ST_96M_APLL);
+}
+
+static int omap2_clk_apll54_enable(struct clk *clk)
+{
+ return omap2_clk_apll_enable(clk, OMAP24XX_ST_54M_APLL);
+}
+
+/* Stop APLL */
+static void omap2_clk_apll_disable(struct clk *clk)
+{
+ u32 cval;
+
+ cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
+ cval &= ~(EN_APLL_LOCKED << clk->enable_bit);
+ cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
+}
+
+/* Public data */
+
+const struct clkops clkops_apll96 = {
+ .enable = omap2_clk_apll96_enable,
+ .disable = omap2_clk_apll_disable,
+};
+
+const struct clkops clkops_apll54 = {
+ .enable = omap2_clk_apll54_enable,
+ .disable = omap2_clk_apll_disable,
+};
+
+/* Public functions */
+
+u32 omap2xxx_get_apll_clkin(void)
+{
+ u32 aplls, srate = 0;
+
+ aplls = cm_read_mod_reg(PLL_MOD, CM_CLKSEL1);
+ aplls &= OMAP24XX_APLLS_CLKIN_MASK;
+ aplls >>= OMAP24XX_APLLS_CLKIN_SHIFT;
+
+ if (aplls == APLLS_CLKIN_19_2MHZ)
+ srate = 19200000;
+ else if (aplls == APLLS_CLKIN_13MHZ)
+ srate = 13000000;
+ else if (aplls == APLLS_CLKIN_12MHZ)
+ srate = 12000000;
+
+ return srate;
+}
+