From cf21405fd51b416f071edb546631a6ecd2112263 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Tue, 21 Sep 2010 10:34:10 -0600 Subject: OMAP2/3: PRM: add module hard reset support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch adds hard-reset support for processor modules (e.g., DSP, IVA) on OMAP2/3 platforms. It's based on the OMAP4 hard-reset support that Benoît developed in the previous patch. This patch is a collaboration between Benoît Cousson and Paul Walmsley . Signed-off-by: Paul Walmsley Cc: Benoît Cousson --- arch/arm/mach-omap2/prm2xxx_3xxx.c | 110 +++++++++++++++++++++++++++++++++++++ 1 file changed, 110 insertions(+) create mode 100644 arch/arm/mach-omap2/prm2xxx_3xxx.c (limited to 'arch/arm/mach-omap2/prm2xxx_3xxx.c') diff --git a/arch/arm/mach-omap2/prm2xxx_3xxx.c b/arch/arm/mach-omap2/prm2xxx_3xxx.c new file mode 100644 index 0000000..421771e --- /dev/null +++ b/arch/arm/mach-omap2/prm2xxx_3xxx.c @@ -0,0 +1,110 @@ +/* + * 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 +#include +#include +#include + +#include +#include +#include + +#include "prm.h" +#include "prm-regbits-24xx.h" +#include "prm-regbits-34xx.h" + +/** + * 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 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; + 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) + * @shift: register bit shift corresponding to the reset line to deassert + * + * 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 shift) +{ + u32 mask; + int c; + + if (!(cpu_is_omap24xx() || cpu_is_omap34xx())) + return -EINVAL; + + mask = 1 << shift; + + /* Check the current status to avoid de-asserting the line twice */ + if (prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTCTRL, mask) == 0) + return -EEXIST; + + /* Clear the reset status by writing 1 to the status bit */ + prm_rmw_mod_reg_bits(0xffffffff, mask, prm_mod, OMAP2_RM_RSTST); + /* de-assert the reset control line */ + prm_rmw_mod_reg_bits(mask, 0, prm_mod, OMAP2_RM_RSTCTRL); + /* wait the status to be set */ + omap_test_timeout(prm_read_mod_bits_shift(prm_mod, OMAP2_RM_RSTST, + mask), + MAX_MODULE_HARDRESET_WAIT, c); + + return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0; +} + -- cgit v1.1