linux/arch/arm/mach-omap2/prm44xx.c

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/*
* OMAP4 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/delay.h>
#include <linux/errno.h>
#include <linux/err.h>
OMAP4: PRCM: add OMAP4-specific accessor/mutator functions In some ways, the OMAP4 PRCM register layout is quite different than the OMAP2/3 PRCM register layout. For example, on OMAP2/3, from a register layout point of view, all CM instances were located in the CM subsystem, and all PRM instances were located in the PRM subsystem. OMAP4 changes this. Now, for example, some CM instances, such as WKUP_CM and EMU_CM, are located in the system PRM subsystem. And a "local PRCM" exists for the MPU - this PRCM combines registers that would normally appear in both CM and PRM instances, but uses its own register layout which matches neither the OMAP2/3 PRCM layout nor the OMAP4 PRCM layout. To try to deal with this, introduce some new functions, omap4_cminst* and omap4_prminst*. The former is to be used when writing to a CM instance register (no matter what subsystem or hardware module it exists in), and the latter, similarly, with PRM instance registers. To determine which "PRCM partition" to write to, the functions take a PRCM instance ID argument. Subsequent patches add these partition IDs to the OMAP4 powerdomain and clockdomain definitions. As far as I can see, there's really no good way to handle these types of register access inconsistencies. This patch seemed like the least bad approach. Moving forward, the long-term goal is to remove all direct PRCM register access from the PM code. PRCM register access should go through layers such as the powerdomain and clockdomain code that can hide the details of how to interact with the specific hardware variant. While here, rename cm4xxx.c to cm44xx.c to match the naming convention of the other OMAP4 PRCM files. Thanks to Santosh Shilimkar <santosh.shilimkar@ti.com>, Rajendra Nayak <rnayak@ti.com>, and Benoît Cousson <b-cousson@ti.com> for some comments. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Benoît Cousson <b-cousson@ti.com> Cc: Rajendra Nayak <rnayak@ti.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-12-22 05:05:14 +01:00
#include <linux/io.h>
#include <plat/common.h>
#include <plat/cpu.h>
#include <plat/prcm.h>
#include "prm44xx.h"
#include "prm-regbits-44xx.h"
/*
* Address offset (in bytes) between the reset control and the reset
* status registers: 4 bytes on OMAP4
*/
#define OMAP4_RST_CTRL_ST_OFFSET 4
OMAP4: PRCM: add OMAP4-specific accessor/mutator functions In some ways, the OMAP4 PRCM register layout is quite different than the OMAP2/3 PRCM register layout. For example, on OMAP2/3, from a register layout point of view, all CM instances were located in the CM subsystem, and all PRM instances were located in the PRM subsystem. OMAP4 changes this. Now, for example, some CM instances, such as WKUP_CM and EMU_CM, are located in the system PRM subsystem. And a "local PRCM" exists for the MPU - this PRCM combines registers that would normally appear in both CM and PRM instances, but uses its own register layout which matches neither the OMAP2/3 PRCM layout nor the OMAP4 PRCM layout. To try to deal with this, introduce some new functions, omap4_cminst* and omap4_prminst*. The former is to be used when writing to a CM instance register (no matter what subsystem or hardware module it exists in), and the latter, similarly, with PRM instance registers. To determine which "PRCM partition" to write to, the functions take a PRCM instance ID argument. Subsequent patches add these partition IDs to the OMAP4 powerdomain and clockdomain definitions. As far as I can see, there's really no good way to handle these types of register access inconsistencies. This patch seemed like the least bad approach. Moving forward, the long-term goal is to remove all direct PRCM register access from the PM code. PRCM register access should go through layers such as the powerdomain and clockdomain code that can hide the details of how to interact with the specific hardware variant. While here, rename cm4xxx.c to cm44xx.c to match the naming convention of the other OMAP4 PRCM files. Thanks to Santosh Shilimkar <santosh.shilimkar@ti.com>, Rajendra Nayak <rnayak@ti.com>, and Benoît Cousson <b-cousson@ti.com> for some comments. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Benoît Cousson <b-cousson@ti.com> Cc: Rajendra Nayak <rnayak@ti.com> Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
2010-12-22 05:05:14 +01:00
/* PRM low-level functions */
/* Read a register in a CM/PRM instance in the PRM module */
u32 omap4_prm_read_inst_reg(s16 inst, u16 reg)
{
return __raw_readl(OMAP44XX_PRM_REGADDR(inst, reg));
}
/* Write into a register in a CM/PRM instance in the PRM module */
void omap4_prm_write_inst_reg(u32 val, s16 inst, u16 reg)
{
__raw_writel(val, OMAP44XX_PRM_REGADDR(inst, reg));
}
/* Read-modify-write a register in a PRM module. Caller must lock */
u32 omap4_prm_rmw_inst_reg_bits(u32 mask, u32 bits, s16 inst, s16 reg)
{
u32 v;
v = omap4_prm_read_inst_reg(inst, reg);
v &= ~mask;
v |= bits;
omap4_prm_write_inst_reg(v, inst, reg);
return v;
}
/* Read a PRM register, AND it, and shift the result down to bit 0 */
/* XXX deprecated */
u32 omap4_prm_read_bits_shift(void __iomem *reg, u32 mask)
{
u32 v;
v = __raw_readl(reg);
v &= mask;
v >>= __ffs(mask);
return v;
}
/* Read-modify-write a register in a PRM module. Caller must lock */
/* XXX deprecated */
u32 omap4_prm_rmw_reg_bits(u32 mask, u32 bits, void __iomem *reg)
{
u32 v;
v = __raw_readl(reg);
v &= ~mask;
v |= bits;
__raw_writel(v, reg);
return v;
}
u32 omap4_prm_set_inst_reg_bits(u32 bits, s16 inst, s16 reg)
{
return omap4_prm_rmw_inst_reg_bits(bits, bits, inst, reg);
}
u32 omap4_prm_clear_inst_reg_bits(u32 bits, s16 inst, s16 reg)
{
return omap4_prm_rmw_inst_reg_bits(bits, 0x0, inst, reg);
}
/**
* omap4_prm_is_hardreset_asserted - read the HW reset line state of
* submodules contained in the hwmod module
* @rstctrl_reg: RM_RSTCTRL register address for this module
* @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 upon parameter error.
*/
int omap4_prm_is_hardreset_asserted(void __iomem *rstctrl_reg, u8 shift)
{
if (!cpu_is_omap44xx() || !rstctrl_reg)
return -EINVAL;
return omap4_prm_read_bits_shift(rstctrl_reg, (1 << shift));
}
/**
* omap4_prm_assert_hardreset - assert the HW reset line of a submodule
* @rstctrl_reg: RM_RSTCTRL register address for this module
* @shift: register bit shift corresponding to the reset line to assert
*
* Some IPs like dsp, ipu 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 omap4_prm_assert_hardreset(void __iomem *rstctrl_reg, u8 shift)
{
u32 mask;
if (!cpu_is_omap44xx() || !rstctrl_reg)
return -EINVAL;
mask = 1 << shift;
omap4_prm_rmw_reg_bits(mask, mask, rstctrl_reg);
return 0;
}
/**
* omap4_prm_deassert_hardreset - deassert a submodule hardreset line and wait
* @rstctrl_reg: RM_RSTCTRL register address for this module
* @shift: register bit shift corresponding to the reset line to deassert
*
* Some IPs like dsp, ipu 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 omap4_prm_deassert_hardreset(void __iomem *rstctrl_reg, u8 shift)
{
u32 mask;
void __iomem *rstst_reg;
int c;
if (!cpu_is_omap44xx() || !rstctrl_reg)
return -EINVAL;
rstst_reg = rstctrl_reg + OMAP4_RST_CTRL_ST_OFFSET;
mask = 1 << shift;
/* Check the current status to avoid de-asserting the line twice */
if (omap4_prm_read_bits_shift(rstctrl_reg, mask) == 0)
return -EEXIST;
/* Clear the reset status by writing 1 to the status bit */
omap4_prm_rmw_reg_bits(0xffffffff, mask, rstst_reg);
/* de-assert the reset control line */
omap4_prm_rmw_reg_bits(mask, 0, rstctrl_reg);
/* wait the status to be set */
omap_test_timeout(omap4_prm_read_bits_shift(rstst_reg, mask),
MAX_MODULE_HARDRESET_WAIT, c);
return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0;
}
void omap4_prm_global_warm_sw_reset(void)
{
u32 v;
v = omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
OMAP4_RM_RSTCTRL);
v |= OMAP4430_RST_GLOBAL_WARM_SW_MASK;
omap4_prm_write_inst_reg(v, OMAP4430_PRM_DEVICE_INST,
OMAP4_RM_RSTCTRL);
/* OCP barrier */
v = omap4_prm_read_inst_reg(OMAP4430_PRM_DEVICE_INST,
OMAP4_RM_RSTCTRL);
}