1 /*
2 * OMAP2xxx osc_clk-specific clock code
3 *
4 * Copyright (C) 2005-2008 Texas Instruments, Inc.
5 * Copyright (C) 2004-2010 Nokia Corporation
6 *
7 * Contacts:
8 * Richard Woodruff <r-woodruff2@ti.com>
9 * Paul Walmsley
10 *
11 * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
12 * Gordon McNutt and RidgeRun, Inc.
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License version 2 as
16 * published by the Free Software Foundation.
17 */
18 #undef DEBUG
19
20 #include <linux/module.h>
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/clk.h>
24 #include <linux/io.h>
25
26 #include <plat/clock.h>
27
28 #include "clock.h"
29 #include "clock2xxx.h"
30 #include "prm2xxx_3xxx.h"
31 #include "prm-regbits-24xx.h"
32
33 /*
34 * XXX This does not actually enable the osc_ck, since the osc_ck must
35 * be running for this function to be called. Instead, this function
36 * is used to disable an autoidle mode on the osc_ck. The existing
37 * clk_enable/clk_disable()-based usecounting for osc_ck should be
38 * replaced with autoidle-based usecounting.
39 */
omap2_enable_osc_ck(struct clk * clk)40 static int omap2_enable_osc_ck(struct clk *clk)
41 {
42 u32 pcc;
43
44 pcc = __raw_readl(prcm_clksrc_ctrl);
45
46 __raw_writel(pcc & ~OMAP_AUTOEXTCLKMODE_MASK, prcm_clksrc_ctrl);
47
48 return 0;
49 }
50
51 /*
52 * XXX This does not actually disable the osc_ck, since doing so would
53 * immediately halt the system. Instead, this function is used to
54 * enable an autoidle mode on the osc_ck. The existing
55 * clk_enable/clk_disable()-based usecounting for osc_ck should be
56 * replaced with autoidle-based usecounting.
57 */
omap2_disable_osc_ck(struct clk * clk)58 static void omap2_disable_osc_ck(struct clk *clk)
59 {
60 u32 pcc;
61
62 pcc = __raw_readl(prcm_clksrc_ctrl);
63
64 __raw_writel(pcc | OMAP_AUTOEXTCLKMODE_MASK, prcm_clksrc_ctrl);
65 }
66
67 const struct clkops clkops_oscck = {
68 .enable = omap2_enable_osc_ck,
69 .disable = omap2_disable_osc_ck,
70 };
71
omap2_osc_clk_recalc(struct clk * clk)72 unsigned long omap2_osc_clk_recalc(struct clk *clk)
73 {
74 return omap2xxx_get_apll_clkin() * omap2xxx_get_sysclkdiv();
75 }
76
77