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Diffstat (limited to 'arch/arm/mach-mx37/iomux.c')
| -rw-r--r-- | arch/arm/mach-mx37/iomux.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/arch/arm/mach-mx37/iomux.c b/arch/arm/mach-mx37/iomux.c new file mode 100644 index 000000000000..03b23047670c --- /dev/null +++ b/arch/arm/mach-mx37/iomux.c @@ -0,0 +1,205 @@ +/* + * Copyright 2007-2009 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +/*! + * @defgroup GPIO_MX37 Board GPIO and Muxing Setup + * @ingroup MSL_MX37 + */ +/*! + * @file mach-mx37/iomux.c + * + * @brief I/O Muxing control functions + * + * @ingroup GPIO_MX37 + */ + +#include <linux/io.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <mach/hardware.h> +#include <mach/gpio.h> +#include "iomux.h" + +/*! + * IOMUX register (base) addresses + */ +enum iomux_reg_addr { + IOMUXGPR0 = IO_ADDRESS(IOMUXC_BASE_ADDR), /*!< General purpose 0 */ + IOMUXGPR1 = IO_ADDRESS(IOMUXC_BASE_ADDR) + 0x004, /*!< General purpose 1 */ + IOMUXSW_MUX_CTL = IO_ADDRESS(IOMUXC_BASE_ADDR) + MUX_I_START, /*!< MUX control */ + IOMUXSW_MUX_END = IO_ADDRESS(IOMUXC_BASE_ADDR) + PAD_I_END, /*!< last MUX control register */ + IOMUXSW_PAD_CTL = IO_ADDRESS(IOMUXC_BASE_ADDR) + PAD_I_START, /*!< Pad control */ + IOMUXSW_PAD_END = IO_ADDRESS(IOMUXC_BASE_ADDR) + PAD_I_END, /*!< last Pad control register */ + IOMUXSW_INPUT_CTL = IO_ADDRESS(IOMUXC_BASE_ADDR) + INPUT_CTL_START, /*!< input select register */ + IOMUXSW_INPUT_END = IO_ADDRESS(IOMUXC_BASE_ADDR) + INPUT_CTL_END, /*!< last input select register */ +}; + +#define MUX_PIN_NUM_MAX (((IOMUXSW_MUX_END - IOMUXSW_MUX_CTL) >> 2) + 1) +#define MUX_INPUT_NUM_MUX (((IOMUXSW_INPUT_END - IOMUXSW_INPUT_CTL) >> 2) + 1) + +static u8 iomux_pin_res_table[MUX_PIN_NUM_MAX]; +static DEFINE_SPINLOCK(gpio_mux_lock); + +/*! + * This function is used to configure a pin through the IOMUX module. + * @param pin a pin number as defined in \b #iomux_pin_name_t + * @param config a configuration as defined in \b #iomux_pin_cfg_t + * + * @return 0 if successful; Non-zero otherwise + */ +static int iomux_config_mux(iomux_pin_name_t pin, iomux_pin_cfg_t config) +{ + u32 ret = 0; + u32 pin_index = PIN_TO_IOMUX_INDEX(pin); + u32 mux_reg = IOMUXSW_MUX_CTL + PIN_TO_IOMUX_MUX(pin); + u32 mux_data = 0; + u8 *rp; + + BUG_ON((mux_reg > IOMUXSW_MUX_END) || (mux_reg < IOMUXSW_MUX_CTL)); + spin_lock(&gpio_mux_lock); + + if (config == IOMUX_CONFIG_GPIO) { + mux_data = PIN_TO_ALT_GPIO(pin); + } else { + mux_data = config; + } + + __raw_writel(mux_data, mux_reg); + + /* + * Log a warning if a pin changes ownership + */ + rp = iomux_pin_res_table + pin_index; + if ((mux_data & *rp) && (*rp != mux_data)) { + /* + * Don't call printk if we're tweaking the console uart or + * we'll deadlock. + */ + printk(KERN_ERR "iomux_config_mux: Warning: iomux pin" + " config changed, pin=%d, " + " prev=0x%x new=0x%x\n", mux_reg, *rp, mux_data); + ret = -EINVAL; + } + *rp = mux_data; + spin_unlock(&gpio_mux_lock); + return ret; +} + +/*! + * Request ownership for an IO pin. This function has to be the first one + * being called before that pin is used. The caller has to check the + * return value to make sure it returns 0. + * + * @param pin a name defined by \b iomux_pin_name_t + * @param config a configuration as defined in \b #iomux_pin_cfg_t + * + * @return 0 if successful; Non-zero otherwise + */ +int mxc_request_iomux(iomux_pin_name_t pin, iomux_pin_cfg_t config) +{ + int ret = iomux_config_mux(pin, config); + int gpio_port = GPIO_TO_PORT(IOMUX_TO_GPIO(pin)); + + if (!ret && (gpio_port != NON_GPIO_PORT) + && ((config == IOMUX_CONFIG_GPIO) + || (config == PIN_TO_ALT_GPIO(pin)))) { + ret |= mxc_request_gpio(pin); + } + return ret; +} + +/*! + * Release ownership for an IO pin + * + * @param pin a name defined by \b iomux_pin_name_t + * @param config config as defined in \b #iomux_pin_ocfg_t + */ +void mxc_free_iomux(iomux_pin_name_t pin, iomux_pin_cfg_t config) +{ + u32 pin_index = PIN_TO_IOMUX_INDEX(pin); + u8 *rp = iomux_pin_res_table + pin_index; + int gpio_port = GPIO_TO_PORT(IOMUX_TO_GPIO(pin)); + + BUG_ON(pin_index > MUX_PIN_NUM_MAX); + *rp = 0; + if ((gpio_port != NON_GPIO_PORT) + && ((config == IOMUX_CONFIG_GPIO) + || (config == PIN_TO_ALT_GPIO(pin)))) { + mxc_free_gpio(pin); + } +} + +/*! + * This function configures the pad value for a IOMUX pin. + * + * @param pin a pin number as defined in \b #iomux_pin_name_t + * @param config the ORed value of elements defined in \b #iomux_pad_config_t + */ +void mxc_iomux_set_pad(iomux_pin_name_t pin, u32 config) +{ + u32 pad_reg = IOMUXSW_PAD_CTL + PIN_TO_IOMUX_PAD(pin); + + BUG_ON((pad_reg > IOMUXSW_PAD_END) || (pad_reg < IOMUXSW_PAD_CTL)); + spin_lock(&gpio_mux_lock); + __raw_writel(config, pad_reg); + spin_unlock(&gpio_mux_lock); +} + +unsigned int mxc_iomux_get_pad(iomux_pin_name_t pin) +{ + volatile u32 pad_reg = IOMUXSW_PAD_CTL + PIN_TO_IOMUX_PAD(pin); + return __raw_readl(pad_reg); +} + +/*! + * This function enables/disables the general purpose function for a particular + * signal. + * + * @param gp one signal as defined in \b #iomux_gp_func_t + * @param en \b #true to enable; \b #false to disable + * @param index 0 for GPR0 and 1 for GPR1 + */ +void mxc_iomux_set_gpr(iomux_gp_func_t gp, bool en, u8 index) +{ + volatile u32 l; + + spin_lock(&gpio_mux_lock); + l = __raw_readl(IOMUXGPR0 + (index << 2)); + if (en) { + l |= gp; + } else { + l &= ~gp; + } + __raw_writel(l, IOMUXGPR0 + (index << 2)); + spin_unlock(&gpio_mux_lock); +} + +/*! + * This function configures input path. + * + * @param input index of input select register as defined in \b #iomux_input_select_t + * @param config the binary value of elements defined in \b #iomux_input_config_t + * */ +void mxc_iomux_set_input(iomux_input_select_t input, u32 config) +{ + u32 reg = IOMUXSW_INPUT_CTL + (input << 2); + + BUG_ON(input >= MUX_INPUT_NUM_MUX); + __raw_writel(config, reg); +} + +EXPORT_SYMBOL(mxc_request_iomux); +EXPORT_SYMBOL(mxc_free_iomux); +EXPORT_SYMBOL(mxc_iomux_set_input); +EXPORT_SYMBOL(mxc_iomux_set_pad); +EXPORT_SYMBOL(mxc_iomux_set_gpr); |