From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/arch/arm/mach-omap2/i2c.c | 191 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 191 insertions(+) create mode 100644 kernel/arch/arm/mach-omap2/i2c.c (limited to 'kernel/arch/arm/mach-omap2/i2c.c') diff --git a/kernel/arch/arm/mach-omap2/i2c.c b/kernel/arch/arm/mach-omap2/i2c.c new file mode 100644 index 000000000..b9d8e47ff --- /dev/null +++ b/kernel/arch/arm/mach-omap2/i2c.c @@ -0,0 +1,191 @@ +/* + * Helper module for board specific I2C bus registration + * + * Copyright (C) 2009 Nokia Corporation. + * + * 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 "soc.h" +#include "omap_hwmod.h" +#include "omap_device.h" +#include "omap-pm.h" + +#include "prm.h" +#include "common.h" +#include "mux.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 + +static void __init omap2_i2c_mux_pins(int bus_id) +{ + char mux_name[sizeof("i2c2_scl.i2c2_scl")]; + + /* First I2C bus is not muxable */ + if (bus_id == 1) + return; + + sprintf(mux_name, "i2c%i_scl.i2c%i_scl", bus_id, bus_id); + omap_mux_init_signal(mux_name, OMAP_PIN_INPUT); + sprintf(mux_name, "i2c%i_sda.i2c%i_sda", bus_id, bus_id); + omap_mux_init_signal(mux_name, OMAP_PIN_INPUT); +} + +/** + * 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 (oh->class->rev == OMAP_I2C_IP_VERSION_2) { + i2c_con = OMAP4_I2C_CON_OFFSET; + } else if (oh->class->rev == OMAP_I2C_IP_VERSION_1) { + i2c_con = OMAP2_I2C_CON_OFFSET; + } else { + WARN(1, "Cannot reset I2C block %s: unsupported revision\n", + oh->name); + return -EINVAL; + } + + /* 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; +} + +static int __init omap_i2c_nr_ports(void) +{ + int ports = 0; + + if (cpu_is_omap24xx()) + ports = 2; + else if (cpu_is_omap34xx()) + ports = 3; + else if (cpu_is_omap44xx()) + ports = 4; + return ports; +} + +/* + * XXX This function is a temporary compatibility wrapper - only + * needed until the I2C driver can be converted to call + * omap_pm_set_max_dev_wakeup_lat() and handle a return code. + */ +static void omap_pm_set_max_mpu_wakeup_lat_compat(struct device *dev, long t) +{ + omap_pm_set_max_mpu_wakeup_lat(dev, t); +} + +static const char name[] = "omap_i2c"; + +int __init omap_i2c_add_bus(struct omap_i2c_bus_platform_data *i2c_pdata, + int bus_id) +{ + int l; + struct omap_hwmod *oh; + struct platform_device *pdev; + char oh_name[MAX_OMAP_I2C_HWMOD_NAME_LEN]; + struct omap_i2c_bus_platform_data *pdata; + struct omap_i2c_dev_attr *dev_attr; + + if (bus_id > omap_i2c_nr_ports()) + return -EINVAL; + + omap2_i2c_mux_pins(bus_id); + + l = snprintf(oh_name, MAX_OMAP_I2C_HWMOD_NAME_LEN, "i2c%d", bus_id); + WARN(l >= MAX_OMAP_I2C_HWMOD_NAME_LEN, + "String buffer overflow in I2C%d device setup\n", bus_id); + oh = omap_hwmod_lookup(oh_name); + if (!oh) { + pr_err("Could not look up %s\n", oh_name); + return -EEXIST; + } + + pdata = i2c_pdata; + /* + * pass the hwmod class's CPU-specific knowledge of I2C IP revision in + * use, and functionality implementation flags, up to the OMAP I2C + * driver via platform data + */ + pdata->rev = oh->class->rev; + + dev_attr = (struct omap_i2c_dev_attr *)oh->dev_attr; + pdata->flags = dev_attr->flags; + + /* + * When waiting for completion of a i2c transfer, we need to + * set a wake up latency constraint for the MPU. This is to + * ensure quick enough wakeup from idle, when transfer + * completes. + * Only omap3 has support for constraints + */ + if (cpu_is_omap34xx()) + pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat; + pdev = omap_device_build(name, bus_id, oh, pdata, + sizeof(struct omap_i2c_bus_platform_data)); + WARN(IS_ERR(pdev), "Could not build omap_device for %s\n", name); + + return PTR_ERR_OR_ZERO(pdev); +} + +static int __init omap_i2c_cmdline(void) +{ + return omap_register_i2c_bus_cmdline(); +} +omap_subsys_initcall(omap_i2c_cmdline); -- cgit 1.2.3-korg