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- // SPDX-License-Identifier: GPL-2.0-only
- /*
- * Helper module for board specific I2C bus registration
- *
- * Copyright (C) 2009 Nokia Corporation.
- */
- #include "soc.h"
- #include "omap_hwmod.h"
- #include "omap_device.h"
- #include "prm.h"
- #include "common.h"
- #include "i2c.h"
- /* In register I2C_CON, Bit 15 is the I2C enable bit */
- #define I2C_EN BIT(15)
- #define OMAP2_I2C_CON_OFFSET 0x24
- #define OMAP4_I2C_CON_OFFSET 0xA4
- #define MAX_OMAP_I2C_HWMOD_NAME_LEN 16
- /**
- * omap_i2c_reset - reset the omap i2c module.
- * @oh: struct omap_hwmod *
- *
- * The i2c moudle in omap2, omap3 had a special sequence to reset. The
- * sequence is:
- * - Disable the I2C.
- * - Write to SOFTRESET bit.
- * - Enable the I2C.
- * - Poll on the RESETDONE bit.
- * The sequence is implemented in below function. This is called for 2420,
- * 2430 and omap3.
- */
- int omap_i2c_reset(struct omap_hwmod *oh)
- {
- u32 v;
- u16 i2c_con;
- int c = 0;
- if (soc_is_omap24xx() || soc_is_omap34xx() || soc_is_am35xx())
- i2c_con = OMAP2_I2C_CON_OFFSET;
- else
- i2c_con = OMAP4_I2C_CON_OFFSET;
- /* Disable I2C */
- v = omap_hwmod_read(oh, i2c_con);
- v &= ~I2C_EN;
- omap_hwmod_write(v, oh, i2c_con);
- /* Write to the SOFTRESET bit */
- omap_hwmod_softreset(oh);
- /* Enable I2C */
- v = omap_hwmod_read(oh, i2c_con);
- v |= I2C_EN;
- omap_hwmod_write(v, oh, i2c_con);
- /* 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;
- }
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