From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- arch/arm/mach-omap2/i2c.c | 74 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 74 insertions(+) create mode 100644 arch/arm/mach-omap2/i2c.c (limited to 'arch/arm/mach-omap2/i2c.c') diff --git a/arch/arm/mach-omap2/i2c.c b/arch/arm/mach-omap2/i2c.c new file mode 100644 index 000000000..3b4b9514f --- /dev/null +++ b/arch/arm/mach-omap2/i2c.c @@ -0,0 +1,74 @@ +// 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; +} -- cgit v1.2.3