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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/arm/mach-omap2/hdq1w.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/mach-omap2/hdq1w.c')
-rw-r--r-- | arch/arm/mach-omap2/hdq1w.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/hdq1w.c b/arch/arm/mach-omap2/hdq1w.c new file mode 100644 index 000000000..c0127f2c5 --- /dev/null +++ b/arch/arm/mach-omap2/hdq1w.c @@ -0,0 +1,64 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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> + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/platform_device.h> + +#include "soc.h" +#include "omap_hwmod.h" +#include "omap_device.h" +#include "hdq1w.h" + +#include "prm.h" +#include "common.h" + +/** + * 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_warn("%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; +} |