2 * OMAP2/3 PRM module functions
4 * Copyright (C) 2010 Texas Instruments, Inc.
5 * Copyright (C) 2010 Nokia Corporation
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/errno.h>
17 #include <linux/err.h>
19 #include <plat/common.h>
21 #include <plat/prcm.h>
24 #include "prm-regbits-24xx.h"
25 #include "prm-regbits-34xx.h"
28 * omap2_prm_is_hardreset_asserted - read the HW reset line state of
29 * submodules contained in the hwmod module
30 * @prm_mod: PRM submodule base (e.g. CORE_MOD)
31 * @shift: register bit shift corresponding to the reset line to check
33 * Returns 1 if the (sub)module hardreset line is currently asserted,
34 * 0 if the (sub)module hardreset line is not currently asserted, or
35 * -EINVAL if called while running on a non-OMAP2/3 chip.
37 int omap2_prm_is_hardreset_asserted(s16 prm_mod
, u8 shift
)
39 if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
42 return prm_read_mod_bits_shift(prm_mod
, OMAP2_RM_RSTCTRL
,
47 * omap2_prm_assert_hardreset - assert the HW reset line of a submodule
48 * @prm_mod: PRM submodule base (e.g. CORE_MOD)
49 * @shift: register bit shift corresponding to the reset line to assert
51 * Some IPs like dsp or iva contain processors that require an HW
52 * reset line to be asserted / deasserted in order to fully enable the
53 * IP. These modules may have multiple hard-reset lines that reset
54 * different 'submodules' inside the IP block. This function will
55 * place the submodule into reset. Returns 0 upon success or -EINVAL
56 * upon an argument error.
58 int omap2_prm_assert_hardreset(s16 prm_mod
, u8 shift
)
62 if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
66 prm_rmw_mod_reg_bits(mask
, mask
, prm_mod
, OMAP2_RM_RSTCTRL
);
72 * omap2_prm_deassert_hardreset - deassert a submodule hardreset line and wait
73 * @prm_mod: PRM submodule base (e.g. CORE_MOD)
74 * @shift: register bit shift corresponding to the reset line to deassert
76 * Some IPs like dsp or iva contain processors that require an HW
77 * reset line to be asserted / deasserted in order to fully enable the
78 * IP. These modules may have multiple hard-reset lines that reset
79 * different 'submodules' inside the IP block. This function will
80 * take the submodule out of reset and wait until the PRCM indicates
81 * that the reset has completed before returning. Returns 0 upon success or
82 * -EINVAL upon an argument error, -EEXIST if the submodule was already out
83 * of reset, or -EBUSY if the submodule did not exit reset promptly.
85 int omap2_prm_deassert_hardreset(s16 prm_mod
, u8 shift
)
90 if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
95 /* Check the current status to avoid de-asserting the line twice */
96 if (prm_read_mod_bits_shift(prm_mod
, OMAP2_RM_RSTCTRL
, mask
) == 0)
99 /* Clear the reset status by writing 1 to the status bit */
100 prm_rmw_mod_reg_bits(0xffffffff, mask
, prm_mod
, OMAP2_RM_RSTST
);
101 /* de-assert the reset control line */
102 prm_rmw_mod_reg_bits(mask
, 0, prm_mod
, OMAP2_RM_RSTCTRL
);
103 /* wait the status to be set */
104 omap_test_timeout(prm_read_mod_bits_shift(prm_mod
, OMAP2_RM_RSTST
,
106 MAX_MODULE_HARDRESET_WAIT
, c
);
108 return (c
== MAX_MODULE_HARDRESET_WAIT
) ? -EBUSY
: 0;