diff options
Diffstat (limited to 'arch/arm/mach-omap2/prm33xx.c')
| -rw-r--r-- | arch/arm/mach-omap2/prm33xx.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/prm33xx.c b/arch/arm/mach-omap2/prm33xx.c new file mode 100644 index 000000000000..e7dbb6cf1255 --- /dev/null +++ b/arch/arm/mach-omap2/prm33xx.c @@ -0,0 +1,135 @@ +/* + * AM33XX PRM functions + * + * Copyright (C) 2011-2012 Texas Instruments Incorporated - http://www.ti.com/ + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/kernel.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/err.h> +#include <linux/io.h> + +#include <plat/common.h> + +#include "common.h" +#include "prm33xx.h" +#include "prm-regbits-33xx.h" + +/* Read a register in a PRM instance */ +u32 am33xx_prm_read_reg(s16 inst, u16 idx) +{ + return __raw_readl(prm_base + inst + idx); +} + +/* Write into a register in a PRM instance */ +void am33xx_prm_write_reg(u32 val, s16 inst, u16 idx) +{ + __raw_writel(val, prm_base + inst + idx); +} + +/* Read-modify-write a register in PRM. Caller must lock */ +u32 am33xx_prm_rmw_reg_bits(u32 mask, u32 bits, s16 inst, s16 idx) +{ + u32 v; + + v = am33xx_prm_read_reg(inst, idx); + v &= ~mask; + v |= bits; + am33xx_prm_write_reg(v, inst, idx); + + return v; +} + +/** + * am33xx_prm_is_hardreset_asserted - read the HW reset line state of + * submodules contained in the hwmod module + * @shift: register bit shift corresponding to the reset line to check + * @inst: CM instance register offset (*_INST macro) + * @rstctrl_offs: RM_RSTCTRL register address offset for this module + * + * 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 am33xx_prm_is_hardreset_asserted(u8 shift, s16 inst, u16 rstctrl_offs) +{ + u32 v; + + v = am33xx_prm_read_reg(inst, rstctrl_offs); + v &= 1 << shift; + v >>= shift; + + return v; +} + +/** + * am33xx_prm_assert_hardreset - assert the HW reset line of a submodule + * @shift: register bit shift corresponding to the reset line to assert + * @inst: CM instance register offset (*_INST macro) + * @rstctrl_reg: RM_RSTCTRL register address for this module + * + * 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 am33xx_prm_assert_hardreset(u8 shift, s16 inst, u16 rstctrl_offs) +{ + u32 mask = 1 << shift; + + am33xx_prm_rmw_reg_bits(mask, mask, inst, rstctrl_offs); + + return 0; +} + +/** + * am33xx_prm_deassert_hardreset - deassert a submodule hardreset line and + * wait + * @shift: register bit shift corresponding to the reset line to deassert + * @inst: CM instance register offset (*_INST macro) + * @rstctrl_reg: RM_RSTCTRL register address for this module + * @rstst_reg: RM_RSTST register address for this module + * + * 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 am33xx_prm_deassert_hardreset(u8 shift, s16 inst, + u16 rstctrl_offs, u16 rstst_offs) +{ + int c; + u32 mask = 1 << shift; + + /* Check the current status to avoid de-asserting the line twice */ + if (am33xx_prm_is_hardreset_asserted(shift, inst, rstctrl_offs) == 0) + return -EEXIST; + + /* Clear the reset status by writing 1 to the status bit */ + am33xx_prm_rmw_reg_bits(0xffffffff, mask, inst, rstst_offs); + /* de-assert the reset control line */ + am33xx_prm_rmw_reg_bits(mask, 0, inst, rstctrl_offs); + /* wait the status to be set */ + + omap_test_timeout(am33xx_prm_is_hardreset_asserted(shift, inst, + rstst_offs), + MAX_MODULE_HARDRESET_WAIT, c); + + return (c == MAX_MODULE_HARDRESET_WAIT) ? -EBUSY : 0; +} |