2 * OMAP36xx-specific clkops
4 * Copyright (C) 2010 Texas Instruments, Inc.
5 * Copyright (C) 2010 Nokia Corporation
11 * Parts of this code are based on code written by
12 * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu,
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License version 2 as
17 * published by the Free Software Foundation.
21 #include <linux/kernel.h>
22 #include <linux/clk.h>
26 #include "clock36xx.h"
30 * omap36xx_pwrdn_clk_enable_with_hsdiv_restore - enable clocks suffering
31 * from HSDivider PWRDN problem Implements Errata ID: i556.
32 * @clk: DPLL output struct clk
34 * 3630 only: dpll3_m3_ck, dpll4_m2_ck, dpll4_m3_ck, dpll4_m4_ck,
35 * dpll4_m5_ck & dpll4_m6_ck dividers gets loaded with reset
36 * valueafter their respective PWRDN bits are set. Any dummy write
37 * (Any other value different from the Read value) to the
38 * corresponding CM_CLKSEL register will refresh the dividers.
40 #ifdef CONFIG_COMMON_CLK
41 int omap36xx_pwrdn_clk_enable_with_hsdiv_restore(struct clk_hw *clk)
43 struct clk_hw_omap *parent;
44 struct clk_hw *parent_hw;
46 static int omap36xx_pwrdn_clk_enable_with_hsdiv_restore(struct clk *clk)
50 u32 dummy_v, orig_v, clksel_shift;
53 /* Clear PWRDN bit of HSDIVIDER */
54 ret = omap2_dflt_clk_enable(clk);
56 #ifdef CONFIG_COMMON_CLK
57 parent_hw = __clk_get_hw(__clk_get_parent(clk->clk));
58 parent = to_clk_hw_omap(parent_hw);
63 /* Restore the dividers */
65 clksel_shift = __ffs(parent->clksel_mask);
66 orig_v = __raw_readl(parent->clksel_reg);
69 /* Write any other value different from the Read value */
70 dummy_v ^= (1 << clksel_shift);
71 __raw_writel(dummy_v, parent->clksel_reg);
73 /* Write the original divider */
74 __raw_writel(orig_v, parent->clksel_reg);
80 #ifndef CONFIG_COMMON_CLK
81 const struct clkops clkops_omap36xx_pwrdn_with_hsdiv_wait_restore = {
82 .enable = omap36xx_pwrdn_clk_enable_with_hsdiv_restore,
83 .disable = omap2_dflt_clk_disable,
84 .find_companion = omap2_clk_dflt_find_companion,
85 .find_idlest = omap2_clk_dflt_find_idlest,