diff options
| -rw-r--r-- | arch/arm/mach-omap2/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/mach-omap2/hdq1w.c | 72 | ||||
| -rw-r--r-- | arch/arm/plat-omap/include/plat/hdq1w.h | 36 |
3 files changed, 109 insertions, 1 deletions
diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile index 4eee0f139cbd..385c083d24b2 100644 --- a/arch/arm/mach-omap2/Makefile +++ b/arch/arm/mach-omap2/Makefile @@ -4,7 +4,7 @@ # Common support obj-y := id.o io.o control.o mux.o devices.o serial.o gpmc.o timer.o pm.o \ - common.o gpio.o dma.o wd_timer.o display.o i2c.o + common.o gpio.o dma.o wd_timer.o display.o i2c.o hdq1w.o omap-2-3-common = irq.o sdrc.o hwmod-common = omap_hwmod.o \ diff --git a/arch/arm/mach-omap2/hdq1w.c b/arch/arm/mach-omap2/hdq1w.c new file mode 100644 index 000000000000..297ebe03f09c --- /dev/null +++ b/arch/arm/mach-omap2/hdq1w.c @@ -0,0 +1,72 @@ +/* + * IP block integration code for the HDQ1W/1-wire IP block + * + * Copyright (C) 2012 Texas Instruments, Inc. + * Paul Walmsley + * + * Based on the I2C reset code in arch/arm/mach-omap2/i2c.c by + * Avinash.H.M <avinashhm@ti.com> + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#include <plat/omap_hwmod.h> +#include <plat/hdq1w.h> + +#include "common.h" + +/* Maximum microseconds to wait for OMAP module to softreset */ +#define MAX_MODULE_SOFTRESET_WAIT 10000 + +/** + * omap_hdq1w_reset - reset the OMAP HDQ1W module + * @oh: struct omap_hwmod * + * + * OCP soft reset the HDQ1W IP block. Section 20.6.1.4 "HDQ1W/1-Wire + * Software Reset" of the OMAP34xx Technical Reference Manual Revision + * ZR (SWPU223R) does not include the rather important fact that, for + * the reset to succeed, the HDQ1W module's internal clock gate must be + * programmed to allow the clock to propagate to the rest of the + * module. In this sense, it's rather similar to the I2C custom reset + * function. Returns 0. + */ +int omap_hdq1w_reset(struct omap_hwmod *oh) +{ + u32 v; + int c = 0; + + /* Write to the SOFTRESET bit */ + omap_hwmod_softreset(oh); + + /* Enable the module's internal clocks */ + v = omap_hwmod_read(oh, HDQ_CTRL_STATUS_OFFSET); + v |= 1 << HDQ_CTRL_STATUS_CLOCKENABLE_SHIFT; + omap_hwmod_write(v, oh, HDQ_CTRL_STATUS_OFFSET); + + /* Poll on RESETDONE bit */ + omap_test_timeout((omap_hwmod_read(oh, + oh->class->sysc->syss_offs) + & SYSS_RESETDONE_MASK), + MAX_MODULE_SOFTRESET_WAIT, c); + + if (c == MAX_MODULE_SOFTRESET_WAIT) + pr_warning("%s: %s: softreset failed (waited %d usec)\n", + __func__, oh->name, MAX_MODULE_SOFTRESET_WAIT); + else + pr_debug("%s: %s: softreset in %d usec\n", __func__, + oh->name, c); + + return 0; +} diff --git a/arch/arm/plat-omap/include/plat/hdq1w.h b/arch/arm/plat-omap/include/plat/hdq1w.h new file mode 100644 index 000000000000..0c1efc846d8d --- /dev/null +++ b/arch/arm/plat-omap/include/plat/hdq1w.h @@ -0,0 +1,36 @@ +/* + * Shared macros and function prototypes for the HDQ1W/1-wire IP block + * + * Copyright (C) 2012 Texas Instruments, Inc. + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ +#ifndef ARCH_ARM_MACH_OMAP2_HDQ1W_H +#define ARCH_ARM_MACH_OMAP2_HDQ1W_H + +#include <plat/omap_hwmod.h> + +/* + * XXX A future cleanup patch should modify + * drivers/w1/masters/omap_hdq.c to use these macros + */ +#define HDQ_CTRL_STATUS_OFFSET 0x0c +#define HDQ_CTRL_STATUS_CLOCKENABLE_SHIFT 5 + + +extern int omap_hdq1w_reset(struct omap_hwmod *oh); + +#endif |