From 0be1621a749907ada0101e4139a1f57168c5410b Mon Sep 17 00:00:00 2001 From: =?utf8?q?Beno=C3=AEt=20Cousson?= Date: Tue, 21 Sep 2010 10:34:10 -0600 Subject: [PATCH] OMAP4: PRM: add module hard reset support MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Most processor modules (e.g., DSP, IVA, IPU) on OMAPs can be reset under the control of the PRM. This patch adds an API for this purpose for OMAP4 devices: int omap4_prm_is_hardreset_asserted(void __iomem *rstctrl_reg, u8 shift); int omap4_prm_assert_hardreset(void __iomem *rstctrl_reg, u8 shift); int omap4_prm_deassert_hardreset(void __iomem *rstctrl_reg, u8 shift); This API is intended to be used only by the hwmod code - a subsequent patch will add that support to hwmod. This patch is a collaboration between Benoît Cousson and Paul Walmsley . Signed-off-by: Paul Walmsley Signed-off-by: Benoît Cousson Tested-by: Kevin Hilman --- arch/arm/mach-omap2/Makefile | 2 +- arch/arm/mach-omap2/prm.h | 13 ++++- arch/arm/mach-omap2/prm44xx.c | 116 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+), 2 deletions(-) create mode 100644 arch/arm/mach-omap2/prm44xx.c diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile index 88d3a1e..c0da784 100644 --- a/arch/arm/mach-omap2/Makefile +++ b/arch/arm/mach-omap2/Makefile @@ -15,7 +15,7 @@ clock-common = clock.o clock_common_data.o \ obj-$(CONFIG_ARCH_OMAP2) += $(omap-2-3-common) $(prcm-common) $(hwmod-common) obj-$(CONFIG_ARCH_OMAP3) += $(omap-2-3-common) $(prcm-common) $(hwmod-common) -obj-$(CONFIG_ARCH_OMAP4) += $(prcm-common) $(hwmod-common) +obj-$(CONFIG_ARCH_OMAP4) += $(prcm-common) prm44xx.o $(hwmod-common) obj-$(CONFIG_OMAP_MCBSP) += mcbsp.o diff --git a/arch/arm/mach-omap2/prm.h b/arch/arm/mach-omap2/prm.h index 588873b..bc7e6e6 100644 --- a/arch/arm/mach-omap2/prm.h +++ b/arch/arm/mach-omap2/prm.h @@ -5,7 +5,7 @@ * OMAP2/3 Power/Reset Management (PRM) register definitions * * Copyright (C) 2007-2009 Texas Instruments, Inc. - * Copyright (C) 2009 Nokia Corporation + * Copyright (C) 2010 Nokia Corporation * * Written by Paul Walmsley * @@ -246,6 +246,10 @@ static inline u32 prm_clear_mod_reg_bits(u32 bits, s16 module, s16 idx) return prm_rmw_mod_reg_bits(bits, 0x0, module, idx); } +int omap4_prm_is_hardreset_asserted(void __iomem *rstctrl_reg, u8 shift); +int omap4_prm_assert_hardreset(void __iomem *rstctrl_reg, u8 shift); +int omap4_prm_deassert_hardreset(void __iomem *rstctrl_reg, u8 shift); + #endif /* @@ -398,4 +402,11 @@ static inline u32 prm_clear_mod_reg_bits(u32 bits, s16 module, s16 idx) #define OMAP_POWERSTATE_MASK (0x3 << 0) +/* + * MAX_MODULE_HARDRESET_WAIT: Maximum microseconds to wait for an OMAP + * submodule to exit hardreset + */ +#define MAX_MODULE_HARDRESET_WAIT 10000 + + #endif diff --git a/arch/arm/mach-omap2/prm44xx.c b/arch/arm/mach-omap2/prm44xx.c new file mode 100644 index 0000000..a1ff918 --- /dev/null +++ b/arch/arm/mach-omap2/prm44xx.c @@ -0,0 +1,116 @@ +/* + * 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 +#include +#include +#include + +#include +#include +#include + +#include "prm.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_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; +} + -- 2.7.4