--- /dev/null
+/*
+ * linux/drivers/i2c/chips/twl4030_gpio.c
+ *
+ * Copyright (C) 2006-2007 Texas Instruments, Inc.
+ * Copyright (C) 2006 MontaVista Software, Inc.
+ *
+ * Code re-arranged and cleaned up by:
+ * Syed Mohammed Khasim <x0khasim@ti.com>
+ *
+ * Initial Code:
+ * Andy Lowe / Nishanth Menon
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel_stat.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/interrupt.h>
+#include <linux/random.h>
+#include <linux/syscalls.h>
+#include <linux/kthread.h>
+
+#include <linux/i2c.h>
+#include <linux/slab.h>
+
+#include <asm/arch/twl4030.h>
+#include <asm/arch/irqs.h>
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+#include <asm/arch/gpio.h>
+#include <asm/arch/mux.h>
+
+#include <linux/device.h>
+
+/****************************************
+* GPIO Block Register definitions
+****************************************/
+
+#define REG_GPIODATAIN1 (0x0)
+#define REG_GPIODATAIN2 (0x1)
+#define REG_GPIODATAIN3 (0x2)
+#define REG_GPIODATADIR1 (0x3)
+#define REG_GPIODATADIR2 (0x4)
+#define REG_GPIODATADIR3 (0x5)
+#define REG_GPIODATAOUT1 (0x6)
+#define REG_GPIODATAOUT2 (0x7)
+#define REG_GPIODATAOUT3 (0x8)
+#define REG_CLEARGPIODATAOUT1 (0x9)
+#define REG_CLEARGPIODATAOUT2 (0xA)
+#define REG_CLEARGPIODATAOUT3 (0xB)
+#define REG_SETGPIODATAOUT1 (0xC)
+#define REG_SETGPIODATAOUT2 (0xD)
+#define REG_SETGPIODATAOUT3 (0xE)
+#define REG_GPIO_DEBEN1 (0xF)
+#define REG_GPIO_DEBEN2 (0x10)
+#define REG_GPIO_DEBEN3 (0x11)
+#define REG_GPIO_CTRL (0x12)
+#define REG_GPIOPUPDCTR1 (0x13)
+#define REG_GPIOPUPDCTR2 (0x14)
+#define REG_GPIOPUPDCTR3 (0x15)
+#define REG_GPIOPUPDCTR4 (0x16)
+#define REG_GPIOPUPDCTR5 (0x17)
+#define REG_GPIO_ISR1A (0x19)
+#define REG_GPIO_ISR2A (0x1A)
+#define REG_GPIO_ISR3A (0x1B)
+#define REG_GPIO_IMR1A (0x1C)
+#define REG_GPIO_IMR2A (0x1D)
+#define REG_GPIO_IMR3A (0x1E)
+#define REG_GPIO_ISR1B (0x1F)
+#define REG_GPIO_ISR2B (0x20)
+#define REG_GPIO_ISR3B (0x21)
+#define REG_GPIO_IMR1B (0x22)
+#define REG_GPIO_IMR2B (0x23)
+#define REG_GPIO_IMR3B (0x24)
+#define REG_GPIO_EDR1 (0x28)
+#define REG_GPIO_EDR2 (0x29)
+#define REG_GPIO_EDR3 (0x2A)
+#define REG_GPIO_EDR4 (0x2B)
+#define REG_GPIO_EDR5 (0x2C)
+#define REG_GPIO_SIH_CTRL (0x2D)
+
+/**** BitField Definitions */
+
+/***** Data banks : 3 banks for 8 gpios each */
+#define DATA_BANK_MAX 8
+#define GET_GPIO_DATA_BANK(x) ((x)/DATA_BANK_MAX)
+#define GET_GPIO_DATA_OFF(x) ((x)%DATA_BANK_MAX)
+
+/* GPIODATADIR Fields each block 0-7 */
+#define BIT_GPIODATADIR_GPIOxDIR(x) (x)
+#define MASK_GPIODATADIR_GPIOxDIR(x) (0x01<<(x))
+
+/* GPIODATAIN Fields each block 0-7 */
+#define BIT_GPIODATAIN_GPIOxIN(x) (x)
+#define MASK_GPIODATAIN_GPIOxIN(x) (0x01<<(x))
+
+/* GPIODATAOUT Fields each block 0-7 */
+#define BIT_GPIODATAOUT_GPIOxOUT(x) (x)
+#define MASK_GPIODATAOUT_GPIOxOUT(x) (0x01<<(x))
+
+/* CLEARGPIODATAOUT Fields */
+#define BIT_CLEARGPIODATAOUT_GPIOxOUT(x) (x)
+#define MASK_CLEARGPIODATAOUT_GPIOxOUT(x) (0x01<<(x))
+
+/* SETGPIODATAOUT Fields */
+#define BIT_SETGPIODATAOUT_GPIOxOUT(x) (x)
+#define MASK_SETGPIODATAOUT_GPIOxOUT(x) (0x01<<(x))
+
+/* GPIO_DEBEN Fields */
+#define BIT_GPIO_DEBEN_GPIOxDEB(x) (x)
+#define MASK_GPIO_DEBEN_GPIOxDEB(x) (0x01<<(x))
+
+/* GPIO_ISR1A Fields */
+#define BIT_GPIO_ISR_GPIOxISR(x) (x)
+#define MASK_GPIO_ISR_GPIOxISR(x) (0x01<<(x))
+
+/* GPIO_IMR1A Fields */
+#define BIT_GPIO_IMR1A_GPIOxIMR(x) (x)
+#define MASK_GPIO_IMR1A_GPIOxIMR(x) (0x01<<(x))
+
+/* GPIO_SIR1 Fields */
+#define BIT_GPIO_SIR1_GPIOxSIR(x) (x)
+#define MASK_GPIO_SIR1_GPIO0SIR (0x01<<(x))
+
+
+/**** Control banks : 5 banks for 4 gpios each */
+#define DATA_CTL_MAX 4
+#define GET_GPIO_CTL_BANK(x) ((x)/DATA_CTL_MAX)
+#define GET_GPIO_CTL_OFF(x) ((x)%DATA_CTL_MAX)
+#define GPIO_BANK_MAX GET_GPIO_CTL_BANK(TWL4030_GPIO_MAX)
+
+/* GPIOPUPDCTRx Fields 5 banks of 4 gpios each */
+#define BIT_GPIOPUPDCTR1_GPIOxPD(x) (2 *(x))
+#define MASK_GPIOPUPDCTR1_GPIOxPD(x) (0x01<<(2*(x)))
+#define BIT_GPIOPUPDCTR1_GPIOxPU(x) ((x) + 1)
+#define MASK_GPIOPUPDCTR1_GPIOxPU(x) (0x01<<(((2*(x)) + 1)))
+
+/* GPIO_EDR1 Fields */
+#define BIT_GPIO_EDR1_GPIOxFALLING(x) (2 *(x))
+#define MASK_GPIO_EDR1_GPIOxFALLING(x) (0x01<<(2*(x)))
+#define BIT_GPIO_EDR1_GPIOxRISING(x) ((x) + 1)
+#define MASK_GPIO_EDR1_GPIOxRISING(x) (0x01<<(((2*(x)) + 1)))
+
+/* GPIO_SIH_CTRL Fields */
+#define BIT_GPIO_SIH_CTRL_EXCLEN (0x000)
+#define MASK_GPIO_SIH_CTRL_EXCLEN (0x00000001)
+#define BIT_GPIO_SIH_CTRL_PENDDIS (0x001)
+#define MASK_GPIO_SIH_CTRL_PENDDIS (0x00000002)
+#define BIT_GPIO_SIH_CTRL_COR (0x002)
+#define MASK_GPIO_SIH_CTRL_COR (0x00000004)
+
+/* GPIO_CTRL Fields */
+#define BIT_GPIO_CTRL_GPIO0CD1 (0x000)
+#define MASK_GPIO_CTRL_GPIO0CD1 (0x00000001)
+#define BIT_GPIO_CTRL_GPIO1CD2 (0x001)
+#define MASK_GPIO_CTRL_GPIO1CD2 (0x00000002)
+#define BIT_GPIO_CTRL_GPIO_ON (0x002)
+#define MASK_GPIO_CTRL_GPIO_ON (0x00000004)
+
+/* Mask for GPIO registers when aggregated into a 32-bit integer */
+#define GPIO_32_MASK 0x0003ffff
+
+/* Data structures */
+static struct semaphore gpio_sem;
+
+/* store usage of each GPIO. - each bit represents one GPIO */
+static unsigned int gpio_usage_count;
+
+/* shadow the imr register */
+static unsigned int gpio_imr_shadow;
+
+/* bitmask of pending requests to unmask gpio interrupts */
+static unsigned int gpio_pending_unmask;
+
+/* pointer to gpio unmask thread struct */
+static struct task_struct *gpio_unmask_thread;
+
+static inline int gpio_twl4030_read(u8 address);
+static inline int gpio_twl4030_write(u8 address, u8 data);
+
+/*
+ * Helper functions to read and write the GPIO ISR and IMR registers as
+ * 32-bit integers. Functions return 0 on success, non-zero otherwise.
+ * The caller must hold a lock on gpio_sem.
+ */
+
+static int gpio_read_isr(unsigned int *isr)
+{
+ int ret;
+
+ *isr = 0;
+ ret = twl4030_i2c_read(TWL4030_MODULE_GPIO, (u8 *) isr,
+ REG_GPIO_ISR1A, 3);
+ le32_to_cpup(isr);
+ *isr &= GPIO_32_MASK;
+
+ return ret;
+}
+
+static int gpio_write_isr(unsigned int isr)
+{
+ int ret;
+
+ isr &= GPIO_32_MASK;
+ /*
+ * The buffer passed to the twl4030_i2c_write() routine must have an
+ * extra byte at the beginning reserved for its internal use.
+ */
+ isr <<= 8;
+ isr = cpu_to_le32(isr);
+ ret = twl4030_i2c_write(TWL4030_MODULE_GPIO, (u8 *) &isr,
+ REG_GPIO_ISR1A, 3);
+ return ret;
+}
+
+static int gpio_write_imr(unsigned int imr)
+{
+ int ret;
+
+ imr &= GPIO_32_MASK;
+ /*
+ * The buffer passed to the twl4030_i2c_write() routine must have an
+ * extra byte at the beginning reserved for its internal use.
+ */
+ imr <<= 8;
+ imr = cpu_to_le32(imr);
+ ret = twl4030_i2c_write(TWL4030_MODULE_GPIO, (u8 *) &imr,
+ REG_GPIO_IMR1A, 3);
+ return ret;
+}
+
+/*
+ * These routines are analagous to the irqchip methods, but they are designed
+ * to be called from thread context with cpu interrupts enabled and with no
+ * locked spinlocks. We call these routines from our custom IRQ handler
+ * instead of the usual irqchip methods.
+ */
+static void twl4030_gpio_mask_and_ack(unsigned int irq)
+{
+ int gpio = irq - IH_TWL4030_GPIO_BASE;
+
+ down(&gpio_sem);
+ /* mask */
+ gpio_imr_shadow |= (1 << gpio);
+ gpio_write_imr(gpio_imr_shadow);
+ /* ack */
+ gpio_write_isr(1 << gpio);
+ up(&gpio_sem);
+}
+
+static void twl4030_gpio_unmask(unsigned int irq)
+{
+ int gpio = irq - IH_TWL4030_GPIO_BASE;
+
+ down(&gpio_sem);
+ gpio_imr_shadow &= ~(1 << gpio);
+ gpio_write_imr(gpio_imr_shadow);
+ up(&gpio_sem);
+}
+
+/*
+ * These are the irqchip methods for the TWL4030 GPIO interrupts.
+ * Our IRQ handle method doesn't call these, but they will be called by
+ * other routines such as setup_irq() and enable_irq(). They are called
+ * with cpu interrupts disabled and with a lock on the irq_controller_lock
+ * spinlock. This complicates matters, because accessing the TWL4030 GPIO
+ * interrupt controller requires I2C bus transactions that can't be initiated
+ * in this context. Our solution is to defer accessing the interrupt
+ * controller to a kernel thread. We only need to support the unmask method.
+ */
+
+static void twl4030_gpio_mask_and_ack_irqchip(unsigned int irq) {}
+static void twl4030_gpio_mask_irqchip(unsigned int irq) {}
+
+static void twl4030_gpio_unmask_irqchip(unsigned int irq)
+{
+ int gpio = irq - IH_TWL4030_GPIO_BASE;
+
+ gpio_pending_unmask |= (1 << gpio);
+ if (gpio_unmask_thread && gpio_unmask_thread->state != TASK_RUNNING)
+ wake_up_process(gpio_unmask_thread);
+}
+
+static struct irq_chip twl4030_gpio_irq_chip = {
+ .name = "twl4030-gpio",
+ .ack = twl4030_gpio_mask_and_ack_irqchip,
+ .mask = twl4030_gpio_mask_irqchip,
+ .unmask = twl4030_gpio_unmask_irqchip,
+};
+
+/*
+ * These are the irqchip methods for the TWL4030 PIH GPIO module interrupt.
+ * The PIH module doesn't have interrupt masking capability, so these
+ * methods are NULL.
+ */
+static void twl4030_gpio_module_ack(unsigned int irq) {}
+static void twl4030_gpio_module_mask(unsigned int irq) {}
+static void twl4030_gpio_module_unmask(unsigned int irq) {}
+static struct irq_chip twl4030_gpio_module_irq_chip = {
+ .ack = twl4030_gpio_module_ack,
+ .mask = twl4030_gpio_module_mask,
+ .unmask = twl4030_gpio_module_unmask,
+};
+
+/*
+ * twl4030 GPIO request function
+ */
+int twl4030_request_gpio(int gpio)
+{
+ int ret = 0;
+
+ if (unlikely(gpio >= TWL4030_GPIO_MAX))
+ return -EPERM;
+
+ down(&gpio_sem);
+ if (gpio_usage_count & (0x1 << gpio))
+ ret = -EBUSY;
+ else {
+ u8 clear_pull[6] = { 0, 0, 0, 0, 0, 0 };
+ /* First time usage? - switch on GPIO module */
+ if (!gpio_usage_count) {
+ ret =
+ gpio_twl4030_write(REG_GPIO_CTRL,
+ MASK_GPIO_CTRL_GPIO_ON);
+ ret = gpio_twl4030_write(REG_GPIO_SIH_CTRL, 0x00);
+ }
+ if (!ret)
+ gpio_usage_count |= (0x1 << gpio);
+
+ ret =
+ twl4030_i2c_write(TWL4030_MODULE_GPIO, clear_pull,
+ REG_GPIOPUPDCTR1, 5);
+ }
+ up(&gpio_sem);
+ return ret;
+}
+
+/*
+ * TWL4030 GPIO free module
+ */
+int twl4030_free_gpio(int gpio)
+{
+ int ret = 0;
+
+ if (unlikely(gpio >= TWL4030_GPIO_MAX))
+ return -EPERM;
+
+ down(&gpio_sem);
+
+ if ((gpio_usage_count & (0x1 << gpio)) == 0)
+ ret = -EPERM;
+ else
+ gpio_usage_count &= ~(0x1 << gpio);
+
+ /* Last time usage? - switch off GPIO module */
+ if (!gpio_usage_count)
+ ret = gpio_twl4030_write(REG_GPIO_CTRL, 0x0);
+
+ up(&gpio_sem);
+ return ret;
+}
+
+/*
+ * Set direction for TWL4030 GPIO
+ */
+int twl4030_set_gpio_direction(int gpio, int is_input)
+{
+ u8 d_bnk = GET_GPIO_DATA_BANK(gpio);
+ u8 d_msk = MASK_GPIODATADIR_GPIOxDIR(GET_GPIO_DATA_OFF(gpio));
+ u8 reg = 0;
+ u8 base = 0;
+ int ret = 0;
+
+ if (unlikely((gpio >= TWL4030_GPIO_MAX)
+ || !(gpio_usage_count & (0x1 << gpio))))
+ return -EPERM;
+
+ base = REG_GPIODATADIR1 + d_bnk;
+
+ down(&gpio_sem);
+ ret = gpio_twl4030_read(base);
+ if (ret >= 0) {
+ if (is_input)
+ reg = (u8) ((ret) & ~(d_msk));
+ else
+ reg = (u8) ((ret) | (d_msk));
+
+ ret = gpio_twl4030_write(base, reg);
+ }
+ up(&gpio_sem);
+ return ret;
+}
+
+/*
+ * To enable/disable GPIO pin on TWL4030
+ */
+int twl4030_set_gpio_dataout(int gpio, int enable)
+{
+ u8 d_bnk = GET_GPIO_DATA_BANK(gpio);
+ u8 d_msk = MASK_GPIODATAOUT_GPIOxOUT(GET_GPIO_DATA_OFF(gpio));
+ u8 base = 0;
+ int ret = 0;
+
+ if (unlikely((gpio >= TWL4030_GPIO_MAX)
+ || !(gpio_usage_count & (0x1 << gpio))))
+ return -EPERM;
+
+ if (enable)
+ base = REG_SETGPIODATAOUT1 + d_bnk;
+ else
+ base = REG_CLEARGPIODATAOUT1 + d_bnk;
+
+ down(&gpio_sem);
+ ret = gpio_twl4030_write(base, d_msk);
+ up(&gpio_sem);
+ return ret;
+}
+
+/*
+ * To get the status of a GPIO pin on TWL4030
+ */
+int twl4030_get_gpio_datain(int gpio)
+{
+ u8 d_bnk = GET_GPIO_DATA_BANK(gpio);
+ u8 d_off = BIT_GPIODATAIN_GPIOxIN(GET_GPIO_DATA_OFF(gpio));
+ u8 base = 0;
+ int ret = 0;
+
+ if (unlikely((gpio >= TWL4030_GPIO_MAX)
+ || !(gpio_usage_count & (0x1 << gpio))))
+ return -EPERM;
+
+ base = REG_GPIODATAIN1 + d_bnk;
+ down(&gpio_sem);
+ ret = gpio_twl4030_read(base);
+ up(&gpio_sem);
+ if (ret > 0)
+ ret = (ret >> d_off) & 0x1;
+
+ return ret;
+}
+
+/*
+ * Configure PULL type for a GPIO pin on TWL4030
+ */
+int twl4030_set_gpio_pull(int gpio, int pull_dircn)
+{
+ u8 c_bnk = GET_GPIO_CTL_BANK(gpio);
+ u8 c_off = GET_GPIO_CTL_OFF(gpio);
+ u8 c_msk = 0;
+ u8 reg = 0;
+ u8 base = 0;
+ int ret = 0;
+
+ if (unlikely((gpio >= TWL4030_GPIO_MAX) ||
+ !(gpio_usage_count & (0x1 << gpio))))
+ return -EPERM;
+
+ base = REG_GPIOPUPDCTR1 + c_bnk;
+ if (pull_dircn == TWL4030_GPIO_PULL_DOWN)
+ c_msk = MASK_GPIOPUPDCTR1_GPIOxPD(c_off);
+ else if (pull_dircn == TWL4030_GPIO_PULL_UP)
+ c_msk = MASK_GPIOPUPDCTR1_GPIOxPU(c_off);
+
+ down(&gpio_sem);
+ ret = gpio_twl4030_read(base);
+ if (ret >= 0) {
+ /* clear the previous up/down values */
+ reg = (u8) (ret);
+ reg &= ~(MASK_GPIOPUPDCTR1_GPIOxPU(c_off) |
+ MASK_GPIOPUPDCTR1_GPIOxPD(c_off));
+ reg |= c_msk;
+ ret = gpio_twl4030_write(base, reg);
+ }
+ up(&gpio_sem);
+ return ret;
+}
+
+/*
+ * Configure Edge control for a GPIO pin on TWL4030
+ */
+int twl4030_set_gpio_edge_ctrl(int gpio, int edge)
+{
+ u8 c_bnk = GET_GPIO_CTL_BANK(gpio);
+ u8 c_off = GET_GPIO_CTL_OFF(gpio);
+ u8 c_msk = 0;
+ u8 reg = 0;
+ u8 base = 0;
+ int ret = 0;
+
+ if (unlikely((gpio >= TWL4030_GPIO_MAX)
+ || !(gpio_usage_count & (0x1 << gpio))))
+ return -EPERM;
+
+ base = REG_GPIO_EDR1 + c_bnk;
+
+ if (edge & TWL4030_GPIO_EDGE_RISING)
+ c_msk |= MASK_GPIO_EDR1_GPIOxRISING(c_off);
+
+ if (edge & TWL4030_GPIO_EDGE_FALLING)
+ c_msk |= MASK_GPIO_EDR1_GPIOxFALLING(c_off);
+
+ down(&gpio_sem);
+ ret = gpio_twl4030_read(base);
+ if (ret >= 0) {
+ /* clear the previous rising/falling values */
+ reg =
+ (u8) (ret &
+ ~(MASK_GPIO_EDR1_GPIOxFALLING(c_off) |
+ MASK_GPIO_EDR1_GPIOxRISING(c_off)));
+ reg |= c_msk;
+ ret = gpio_twl4030_write(base, reg);
+ }
+ up(&gpio_sem);
+ return ret;
+}
+
+/*
+ * Configure debounce timing value for a GPIO pin on TWL4030
+ */
+int twl4030_set_gpio_debounce(int gpio, int enable)
+{
+ u8 d_bnk = GET_GPIO_DATA_BANK(gpio);
+ u8 d_msk = MASK_GPIO_DEBEN_GPIOxDEB(GET_GPIO_DATA_OFF(gpio));
+ u8 reg = 0;
+ u8 base = 0;
+ int ret = 0;
+
+ if (unlikely((gpio >= TWL4030_GPIO_MAX)
+ || !(gpio_usage_count & (0x1 << gpio))))
+ return -EPERM;
+
+ base = REG_GPIO_DEBEN1 + d_bnk;
+ down(&gpio_sem);
+ ret = gpio_twl4030_read(base);
+ if (ret >= 0) {
+ if (enable)
+ reg = (u8) ((ret) | (d_msk));
+ else
+ reg = (u8) ((ret) & ~(d_msk));
+
+ ret = gpio_twl4030_write(base, reg);
+ }
+ up(&gpio_sem);
+ return ret;
+}
+
+/*
+ * Configure Card detect for GPIO pin on TWL4030
+ */
+int twl4030_set_gpio_card_detect(int gpio, int enable)
+{
+ u8 reg = 0;
+ u8 msk = (1 << gpio);
+ int ret = 0;
+
+ /* Only GPIO 0 or 1 can be used for CD feature.. */
+ if (unlikely((gpio >= TWL4030_GPIO_MAX)
+ || !(gpio_usage_count & (0x1 << gpio))
+ || (gpio >= TWL4030_GPIO_MAX_CD))) {
+ return -EPERM;
+ }
+
+ down(&gpio_sem);
+ ret = gpio_twl4030_read(REG_GPIO_CTRL);
+ if (ret >= 0) {
+ if (enable)
+ reg = (u8) (ret | msk);
+ else
+ reg = (u8) (ret & ~msk);
+
+ ret = gpio_twl4030_write(REG_GPIO_CTRL, reg);
+ }
+ up(&gpio_sem);
+ return (ret);
+}
+
+/**** MODULE FUNCTIONS ***/
+
+/*
+ * To configure TWL4030 GPIO module registers
+ */
+static inline int gpio_twl4030_write(u8 address, u8 data)
+{
+ int ret = 0;
+
+ ret = twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, data, address);
+ return ret;
+}
+
+/*
+ * To read a TWL4030 GPIO module register
+ */
+static inline int gpio_twl4030_read(u8 address)
+{
+ u8 data;
+ int ret = 0;
+
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_GPIO, &data, address);
+ if (ret >= 0)
+ ret = data;
+ return ret;
+}
+
+/*
+ * gpio_unmask_thread() runs as a kernel thread. It is awakened by the unmask
+ * method for the GPIO interrupts. It unmasks all of the GPIO interrupts
+ * specified in the gpio_pending_unmask bitmask. We have to do the unmasking
+ * in a kernel thread rather than directly in the unmask method because of the
+ * need to access the TWL4030 via the I2C bus. Note that we don't need to be
+ * concerned about race conditions where the request to unmask a GPIO interrupt
+ * has already been cancelled before this thread does the unmasking. If a GPIO
+ * interrupt is improperly unmasked, then the IRQ handler for it will mask it
+ * when an interrupt occurs.
+ */
+static int twl4030_gpio_unmask_thread(void *data)
+{
+ current->flags |= PF_NOFREEZE;
+
+ while (!kthread_should_stop()) {
+ int irq;
+ unsigned int gpio_unmask;
+
+ local_irq_disable();
+ gpio_unmask = gpio_pending_unmask;
+ gpio_pending_unmask = 0;
+ local_irq_enable();
+
+ for (irq = IH_TWL4030_GPIO_BASE; 0 != gpio_unmask;
+ gpio_unmask >>= 1, irq++) {
+ if (gpio_unmask & 0x1)
+ twl4030_gpio_unmask(irq);
+ }
+
+ local_irq_disable();
+ if (!gpio_pending_unmask)
+ set_current_state(TASK_INTERRUPTIBLE);
+ local_irq_enable();
+
+ schedule();
+ }
+ set_current_state(TASK_RUNNING);
+ return 0;
+}
+
+/*
+ * do_twl4030_gpio_irq() is the desc->handle method for each of the twl4030
+ * gpio interrupts. It executes in kernel thread context.
+ * On entry, cpu interrupts are enabled.
+ */
+static void do_twl4030_gpio_irq(unsigned int irq, irq_desc_t *desc)
+{
+ struct irqaction *action;
+ const unsigned int cpu = smp_processor_id();
+
+ desc->status |= IRQ_LEVEL;
+
+ /*
+ * Acknowledge, clear _AND_ disable the interrupt.
+ */
+ twl4030_gpio_mask_and_ack(irq);
+
+ if (!desc->depth) {
+ kstat_cpu(cpu).irqs[irq]++;
+
+ action = desc->action;
+ if (action) {
+ int ret;
+ int status = 0;
+ int retval = 0;
+ do {
+ /* Call the ISR with cpu interrupts enabled. */
+ ret = action->handler(irq, action->dev_id);
+ if (ret == IRQ_HANDLED)
+ status |= action->flags;
+ retval |= ret;
+ action = action->next;
+ } while (action);
+
+ if (retval != IRQ_HANDLED)
+ printk(KERN_ERR "ISR for TWL4030 GPIO"
+ " irq %d can't handle interrupt\n",
+ irq);
+
+ if (!desc->depth)
+ twl4030_gpio_unmask(irq);
+ }
+ }
+}
+
+/*
+ * do_twl4030_gpio_module_irq() is the desc->handle method for the twl4030 gpio
+ * module interrupt. It executes in kernel thread context.
+ * This is a chained interrupt, so there is no desc->action method for it.
+ * We query the gpio module interrupt controller in the twl4030 to determine
+ * which gpio lines are generating interrupt requests, and then call the
+ * desc->handle method for each gpio that needs service.
+ * On entry, cpu interrupts are disabled.
+ */
+static void do_twl4030_gpio_module_irq(unsigned int irq, irq_desc_t *desc)
+{
+ const unsigned int cpu = smp_processor_id();
+
+ desc->status |= IRQ_LEVEL;
+ /*
+ * The desc->handle method would normally call the desc->chip->ack
+ * method here, but we won't bother since our ack method is NULL.
+ */
+ if (!desc->depth) {
+ int gpio_irq;
+ unsigned int gpio_isr;
+
+ kstat_cpu(cpu).irqs[irq]++;
+ local_irq_enable();
+
+ down(&gpio_sem);
+ if (gpio_read_isr(&gpio_isr))
+ gpio_isr = 0;
+ up(&gpio_sem);
+
+ for (gpio_irq = IH_TWL4030_GPIO_BASE; 0 != gpio_isr;
+ gpio_isr >>= 1, gpio_irq++) {
+ if (gpio_isr & 0x1) {
+ irq_desc_t *d = irq_desc + gpio_irq;
+ d->handle_irq(gpio_irq, d);
+ }
+ }
+
+ local_irq_disable();
+ /*
+ * Here is where we should call the unmask method, but again we
+ * won't bother since it is NULL.
+ */
+ }
+}
+
+/* TWL4030 Initialization module */
+static int __init gpio_twl4030_init(void)
+{
+ int ret;
+ int irq = 0;
+
+ /* init the global locking sem */
+ sema_init(&gpio_sem, 1);
+
+ /* All GPIO interrupts are initially masked */
+ gpio_pending_unmask = 0;
+ gpio_imr_shadow = GPIO_32_MASK;
+ ret = gpio_write_imr(gpio_imr_shadow);
+ if (!ret) {
+ /*
+ * Create a kernel thread to handle deferred unmasking of gpio
+ * interrupts.
+ */
+ gpio_unmask_thread = kthread_create(twl4030_gpio_unmask_thread,
+ NULL, "twl4030 gpio");
+ if (!gpio_unmask_thread) {
+ printk(KERN_ERR
+ "%s: could not create twl4030 gpio unmask thread!\n",
+ __FUNCTION__);
+ ret = -ENOMEM;
+ }
+ }
+
+ if (!ret) {
+ /* install an irq handler for each of the gpio interrupts */
+ for (irq = IH_TWL4030_GPIO_BASE; irq < IH_TWL4030_GPIO_END;
+ irq++) {
+ set_irq_chip(irq, &twl4030_gpio_irq_chip);
+ set_irq_handler(irq, do_twl4030_gpio_irq);
+ set_irq_flags(irq, IRQF_VALID);
+ }
+
+ /*
+ * Install an irq handler to demultiplex the gpio module
+ * interrupt.
+ */
+ set_irq_chip(TWL4030_MODIRQ_GPIO,
+ &twl4030_gpio_module_irq_chip);
+ set_irq_chained_handler(TWL4030_MODIRQ_GPIO,
+ do_twl4030_gpio_module_irq);
+ }
+
+ printk(KERN_INFO "TWL4030 GPIO Demux: IRQ Range %d to %d,"
+ " Initialization %s\n", IH_TWL4030_GPIO_BASE,
+ IH_TWL4030_GPIO_END, (ret) ? "Failed" : "Success");
+ return ret;
+}
+
+/* TWL GPIO exit module */
+static void __exit gpio_twl4030_exit(void)
+{
+ int irq;
+
+ /* uninstall the gpio demultiplexing interrupt handler */
+ set_irq_handler(TWL4030_MODIRQ_GPIO, NULL);
+ set_irq_flags(TWL4030_MODIRQ_GPIO, 0);
+
+ /* uninstall the irq handler for each of the gpio interrupts */
+ for (irq = IH_TWL4030_GPIO_BASE; irq < IH_TWL4030_GPIO_END; irq++) {
+ set_irq_handler(irq, NULL);
+ set_irq_flags(irq, 0);
+ }
+
+ /* stop the gpio unmask kernel thread */
+ if (gpio_unmask_thread) {
+ kthread_stop(gpio_unmask_thread);
+ gpio_unmask_thread = NULL;
+ }
+}
+
+module_init(gpio_twl4030_init);
+module_exit(gpio_twl4030_exit);
+
+EXPORT_SYMBOL(twl4030_request_gpio);
+EXPORT_SYMBOL(twl4030_free_gpio);
+EXPORT_SYMBOL(twl4030_set_gpio_direction);
+EXPORT_SYMBOL(twl4030_set_gpio_dataout);
+EXPORT_SYMBOL(twl4030_get_gpio_datain);
+EXPORT_SYMBOL(twl4030_set_gpio_pull);
+EXPORT_SYMBOL(twl4030_set_gpio_edge_ctrl);
+EXPORT_SYMBOL(twl4030_set_gpio_debounce);
+EXPORT_SYMBOL(twl4030_set_gpio_card_detect);
+
+MODULE_AUTHOR("Texas Instruments, Inc.");
+MODULE_DESCRIPTION("GPIO interface for TWL4030");
+MODULE_LICENSE("GPL");
projects / linux-2.6-omap-h63xx.git / commitdiff