linux/arch/arm/mach-omap2/prm2xxx_3xxx.c
omar ramirez cc1226e763 OMAP2+: hwmod: use status bit info for reset line
On OMAP2 and OMAP3 the reset ctrl shift doesn't match the
status bit, as it does on OMAP4, when handling the reset lines.

This patch adds a new member in the reset info structure, so now it
can be added as part of hwmod data, and checked accordingly for
OMAP2 or 3; otherwise, there could be cases when the shift masks
doesn't match both of the registers, and a successful reset might
throw an error message or vice versa.

Signed-off-by: Omar Ramirez Luna <omar.ramirez@ti.com>
[paul@pwsan.com: added a warning if st_shift used on OMAP4; renamed 'r'
 variable; improved some documentation]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2011-03-10 03:23:56 -07:00

159 lines
4.6 KiB
C

/*
* OMAP2/3 PRM module functions
*
* Copyright (C) 2010 Texas Instruments, Inc.
* Copyright (C) 2010 Nokia Corporation
* Benoît Cousson
* Paul Walmsley
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/io.h>
#include <plat/common.h>
#include <plat/cpu.h>
#include <plat/prcm.h>
#include "prm2xxx_3xxx.h"
#include "cm2xxx_3xxx.h"
#include "prm-regbits-24xx.h"
#include "prm-regbits-34xx.h"
u32 omap2_prm_read_mod_reg(s16 module, u16 idx)
{
return __raw_readl(prm_base + module + idx);
}
void omap2_prm_write_mod_reg(u32 val, s16 module, u16 idx)
{
__raw_writel(val, prm_base + module + idx);
}
/* Read-modify-write a register in a PRM module. Caller must lock */
u32 omap2_prm_rmw_mod_reg_bits(u32 mask, u32 bits, s16 module, s16 idx)
{
u32 v;
v = omap2_prm_read_mod_reg(module, idx);
v &= ~mask;
v |= bits;
omap2_prm_write_mod_reg(v, module, idx);
return v;
}
/* Read a PRM register, AND it, and shift the result down to bit 0 */
u32 omap2_prm_read_mod_bits_shift(s16 domain, s16 idx, u32 mask)
{
u32 v;
v = omap2_prm_read_mod_reg(domain, idx);
v &= mask;
v >>= __ffs(mask);
return v;
}
u32 omap2_prm_set_mod_reg_bits(u32 bits, s16 module, s16 idx)
{
return omap2_prm_rmw_mod_reg_bits(bits, bits, module, idx);
}
u32 omap2_prm_clear_mod_reg_bits(u32 bits, s16 module, s16 idx)
{
return omap2_prm_rmw_mod_reg_bits(bits, 0x0, module, idx);
}
/**
* omap2_prm_is_hardreset_asserted - read the HW reset line state of
* submodules contained in the hwmod module
* @prm_mod: PRM submodule base (e.g. CORE_MOD)
* @shift: register bit shift corresponding to the reset line to check
*
* Returns 1 if the (sub)module hardreset line is currently asserted,
* 0 if the (sub)module hardreset line is not currently asserted, or
* -EINVAL if called while running on a non-OMAP2/3 chip.
*/
int omap2_prm_is_hardreset_asserted(s16 prm_mod, u8 shift)
{
if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
return -EINVAL;
return omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL,
(1 << shift));
}
/**
* omap2_prm_assert_hardreset - assert the HW reset line of a submodule
* @prm_mod: PRM submodule base (e.g. CORE_MOD)
* @shift: register bit shift corresponding to the reset line to assert
*
* Some IPs like dsp or iva contain processors that require an HW
* reset line to be asserted / deasserted in order to fully enable the
* IP. These modules may have multiple hard-reset lines that reset
* different 'submodules' inside the IP block. This function will
* place the submodule into reset. Returns 0 upon success or -EINVAL
* upon an argument error.
*/
int omap2_prm_assert_hardreset(s16 prm_mod, u8 shift)
{
u32 mask;
if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
return -EINVAL;
mask = 1 << shift;
omap2_prm_rmw_mod_reg_bits(mask, mask, prm_mod, OMAP2_RM_RSTCTRL);
return 0;
}
/**
* omap2_prm_deassert_hardreset - deassert a submodule hardreset line and wait
* @prm_mod: PRM submodule base (e.g. CORE_MOD)
* @rst_shift: register bit shift corresponding to the reset line to deassert
* @st_shift: register bit shift for the status of the deasserted submodule
*
* Some IPs like dsp or iva contain processors that require an HW
* reset line to be asserted / deasserted in order to fully enable the
* IP. These modules may have multiple hard-reset lines that reset
* different 'submodules' inside the IP block. This function will
* take the submodule out of reset and wait until the PRCM indicates
* that the reset has completed before returning. Returns 0 upon success or
* -EINVAL upon an argument error, -EEXIST if the submodule was already out
* of reset, or -EBUSY if the submodule did not exit reset promptly.
*/
int omap2_prm_deassert_hardreset(s16 prm_mod, u8 rst_shift, u8 st_shift)
{
u32 rst, st;
int c;
if (!(cpu_is_omap24xx() || cpu_is_omap34xx()))
return -EINVAL;
rst = 1 << rst_shift;
st = 1 << st_shift;
/* Check the current status to avoid de-asserting the line twice */
if (omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL, rst) == 0)
return -EEXIST;
/* Clear the reset status by writing 1 to the status bit */
omap2_prm_rmw_mod_reg_bits(0xffffffff, st, prm_mod, OMAP2_RM_RSTST);
/* de-assert the reset control line */
omap2_prm_rmw_mod_reg_bits(rst, 0, prm_mod, OMAP2_RM_RSTCTRL);
/* wait the status to be set */
omap_test_timeout(omap2_prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTST,
st),
MAX_MODULE_HARDRESET_WAIT, c);
return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
}