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Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 246 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000436.674189849@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
74 lines
1.7 KiB
C
74 lines
1.7 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Helper module for board specific I2C bus registration
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*
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* Copyright (C) 2009 Nokia Corporation.
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*/
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#include "soc.h"
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#include "omap_hwmod.h"
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#include "omap_device.h"
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#include "prm.h"
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#include "common.h"
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#include "i2c.h"
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/* In register I2C_CON, Bit 15 is the I2C enable bit */
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#define I2C_EN BIT(15)
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#define OMAP2_I2C_CON_OFFSET 0x24
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#define OMAP4_I2C_CON_OFFSET 0xA4
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#define MAX_OMAP_I2C_HWMOD_NAME_LEN 16
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/**
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* omap_i2c_reset - reset the omap i2c module.
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* @oh: struct omap_hwmod *
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*
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* The i2c moudle in omap2, omap3 had a special sequence to reset. The
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* sequence is:
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* - Disable the I2C.
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* - Write to SOFTRESET bit.
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* - Enable the I2C.
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* - Poll on the RESETDONE bit.
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* The sequence is implemented in below function. This is called for 2420,
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* 2430 and omap3.
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*/
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int omap_i2c_reset(struct omap_hwmod *oh)
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{
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u32 v;
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u16 i2c_con;
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int c = 0;
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if (soc_is_omap24xx() || soc_is_omap34xx() || soc_is_am35xx())
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i2c_con = OMAP2_I2C_CON_OFFSET;
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else
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i2c_con = OMAP4_I2C_CON_OFFSET;
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/* Disable I2C */
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v = omap_hwmod_read(oh, i2c_con);
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v &= ~I2C_EN;
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omap_hwmod_write(v, oh, i2c_con);
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/* Write to the SOFTRESET bit */
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omap_hwmod_softreset(oh);
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/* Enable I2C */
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v = omap_hwmod_read(oh, i2c_con);
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v |= I2C_EN;
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omap_hwmod_write(v, oh, i2c_con);
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/* Poll on RESETDONE bit */
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omap_test_timeout((omap_hwmod_read(oh,
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oh->class->sysc->syss_offs)
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& SYSS_RESETDONE_MASK),
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MAX_MODULE_SOFTRESET_WAIT, c);
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if (c == MAX_MODULE_SOFTRESET_WAIT)
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pr_warn("%s: %s: softreset failed (waited %d usec)\n",
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__func__, oh->name, MAX_MODULE_SOFTRESET_WAIT);
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else
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pr_debug("%s: %s: softreset in %d usec\n", __func__,
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oh->name, c);
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return 0;
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}
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