a7e069fc5a
This patch implements a workaround for the DPLL HS divider limitation
in OMAP3630 as given by Errata ID: i556.
Errata:
When PWRDN bit is set, it resets the internal HSDIVIDER divide-by value (Mx).
The reset value gets loaded instead of the previous value.
The following HSDIVIDERs exhibit above behavior:
. DPLL4 : M6 / M5 / M4 / M3 / M2 (CM_CLKEN_PLL[31:26] register bits)
. DPLL3 : M3 (CM_CLKEN_PLL[12] register bit).
Work Around:
It is mandatory to apply the following sequence to ensure the write
value will
be loaded in DPLL HSDIVIDER FSM:
The global sequence when using PWRDN bit is the following:
. Disable Mx HSDIVIDER clock output related functional clock enable bits
(in CM_FCLKEN_xxx / CM_ICLKEN_xxx)
. Enable PWRDN bit of HSDIVIDER
. Disable PWRDN bit of HSDIVIDER
. Read current HSDIVIDER register value
. Write different value in HSDIVIDER register
. Write expected value in HSDIVIDER register
. Enable Mx HSDIVIDER clock output related functional clocks
(CM_FCLKEN_xxx / CM_ICLKEN_xxx)
Signed-off-by: Mike Turquette <mturquette@ti.com>
Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Vijaykumar GN <vijaykumar.gn@ti.com>
[paul@pwsan.com: updated patch to apply; made workaround function static;
marked as being 36xx-specific]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
33 lines
1,023 B
C
33 lines
1,023 B
C
/*
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* OMAP3 clock function prototypes and macros
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*
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* Copyright (C) 2007-2009 Texas Instruments, Inc.
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* Copyright (C) 2007-2009 Nokia Corporation
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*/
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#ifndef __ARCH_ARM_MACH_OMAP2_CLOCK_34XX_H
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#define __ARCH_ARM_MACH_OMAP2_CLOCK_34XX_H
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int omap3xxx_clk_init(void);
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int omap3_dpll4_set_rate(struct clk *clk, unsigned long rate);
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int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate);
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void omap3_clk_lock_dpll5(void);
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extern struct clk *sdrc_ick_p;
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extern struct clk *arm_fck_p;
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/* OMAP34xx-specific clkops */
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extern const struct clkops clkops_omap3430es2_ssi_wait;
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extern const struct clkops clkops_omap3430es2_hsotgusb_wait;
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extern const struct clkops clkops_omap3430es2_dss_usbhost_wait;
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extern const struct clkops omap3_clkops_noncore_dpll_ops;
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/* AM35xx-specific clkops */
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extern const struct clkops clkops_am35xx_ipss_module_wait;
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extern const struct clkops clkops_am35xx_ipss_wait;
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/* OMAP36xx-specific clkops */
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extern const struct clkops clkops_omap36xx_pwrdn_with_hsdiv_wait_restore;
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#endif
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