From c120ea2c555cf3a2948580328fcd718e592399c4 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Fri, 10 Oct 2008 14:19:49 -0700 Subject: [PATCH] create twl4030-irq.c Split the IRQ support out of twl4030-core.c into twl4030-irq.c, including some minor tidy-ups and a note_interrupt() paranoia in case of flakiness with some PIH interrupt. Signed-off-by: David Brownell Signed-off-by: Tony Lindgren --- drivers/mfd/Makefile | 2 +- drivers/mfd/twl4030-core.c | 412 +------------------------------------ drivers/mfd/twl4030-irq.c | 408 ++++++++++++++++++++++++++++++++++++ 3 files changed, 420 insertions(+), 402 deletions(-) create mode 100644 drivers/mfd/twl4030-irq.c diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index 5650e7b4e8e..92531f04c81 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -12,7 +12,7 @@ obj-$(CONFIG_MFD_T7L66XB) += t7l66xb.o obj-$(CONFIG_MFD_TC6387XB) += tc6387xb.o obj-$(CONFIG_MFD_TC6393XB) += tc6393xb.o -obj-$(CONFIG_TWL4030_CORE) += twl4030-core.o +obj-$(CONFIG_TWL4030_CORE) += twl4030-core.o twl4030-irq.o obj-$(CONFIG_MFD_CORE) += mfd-core.o diff --git a/drivers/mfd/twl4030-core.c b/drivers/mfd/twl4030-core.c index fd9a0160202..ab0a6bda459 100644 --- a/drivers/mfd/twl4030-core.c +++ b/drivers/mfd/twl4030-core.c @@ -27,15 +27,11 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ -#include #include #include -#include -#include -#include -#include #include #include +#include #include #include @@ -93,26 +89,6 @@ #define twl_has_usb() false #endif -static inline void activate_irq(int irq) -{ -#ifdef CONFIG_ARM - /* ARM requires an extra step to clear IRQ_NOREQUEST, which it - * sets on behalf of every irq_chip. Also sets IRQ_NOPROBE. - */ - set_irq_flags(irq, IRQF_VALID); -#else - /* same effect on other architectures */ - set_irq_noprobe(irq); -#endif -} - -/* Primary Interrupt Handler on TWL4030 Registers */ - -/* Register Definitions */ - -#define REG_PIH_ISR_P1 (0x1) -#define REG_PIH_ISR_P2 (0x2) -#define REG_PIH_SIR (0x3) /* Triton Core internal information (BEGIN) */ @@ -175,138 +151,6 @@ static inline void activate_irq(int irq) /*----------------------------------------------------------------------*/ -/** - * struct twl4030_mod_iregs - TWL module IMR/ISR regs to mask/clear at init - * @mod_no: TWL4030 module number (e.g., TWL4030_MODULE_GPIO) - * @sih_ctrl: address of module SIH_CTRL register - * @reg_cnt: number of IMR/ISR regs - * @imrs: pointer to array of TWL module interrupt mask register indices - * @isrs: pointer to array of TWL module interrupt status register indices - * - * Ties together TWL4030 modules and lists of IMR/ISR registers to mask/clear - * during twl_init_irq(). - */ -struct twl4030_mod_iregs { - const u8 mod_no; - const u8 sih_ctrl; - const u8 reg_cnt; - const u8 *imrs; - const u8 *isrs; -}; - -/* TWL4030 INT module interrupt mask registers */ -static const u8 __initconst twl4030_int_imr_regs[] = { - TWL4030_INT_PWR_IMR1, - TWL4030_INT_PWR_IMR2, -}; - -/* TWL4030 INT module interrupt status registers */ -static const u8 __initconst twl4030_int_isr_regs[] = { - TWL4030_INT_PWR_ISR1, - TWL4030_INT_PWR_ISR2, -}; - -/* TWL4030 INTERRUPTS module interrupt mask registers */ -static const u8 __initconst twl4030_interrupts_imr_regs[] = { - TWL4030_INTERRUPTS_BCIIMR1A, - TWL4030_INTERRUPTS_BCIIMR1B, - TWL4030_INTERRUPTS_BCIIMR2A, - TWL4030_INTERRUPTS_BCIIMR2B, -}; - -/* TWL4030 INTERRUPTS module interrupt status registers */ -static const u8 __initconst twl4030_interrupts_isr_regs[] = { - TWL4030_INTERRUPTS_BCIISR1A, - TWL4030_INTERRUPTS_BCIISR1B, - TWL4030_INTERRUPTS_BCIISR2A, - TWL4030_INTERRUPTS_BCIISR2B, -}; - -/* TWL4030 MADC module interrupt mask registers */ -static const u8 __initconst twl4030_madc_imr_regs[] = { - TWL4030_MADC_IMR1, - TWL4030_MADC_IMR2, -}; - -/* TWL4030 MADC module interrupt status registers */ -static const u8 __initconst twl4030_madc_isr_regs[] = { - TWL4030_MADC_ISR1, - TWL4030_MADC_ISR2, -}; - -/* TWL4030 keypad module interrupt mask registers */ -static const u8 __initconst twl4030_keypad_imr_regs[] = { - TWL4030_KEYPAD_KEYP_IMR1, - TWL4030_KEYPAD_KEYP_IMR2, -}; - -/* TWL4030 keypad module interrupt status registers */ -static const u8 __initconst twl4030_keypad_isr_regs[] = { - TWL4030_KEYPAD_KEYP_ISR1, - TWL4030_KEYPAD_KEYP_ISR2, -}; - -/* TWL4030 GPIO module interrupt mask registers */ -static const u8 __initconst twl4030_gpio_imr_regs[] = { - REG_GPIO_IMR1A, - REG_GPIO_IMR1B, - REG_GPIO_IMR2A, - REG_GPIO_IMR2B, - REG_GPIO_IMR3A, - REG_GPIO_IMR3B, -}; - -/* TWL4030 GPIO module interrupt status registers */ -static const u8 __initconst twl4030_gpio_isr_regs[] = { - REG_GPIO_ISR1A, - REG_GPIO_ISR1B, - REG_GPIO_ISR2A, - REG_GPIO_ISR2B, - REG_GPIO_ISR3A, - REG_GPIO_ISR3B, -}; - -/* TWL4030 modules that have IMR/ISR registers that must be masked/cleared */ -static const struct twl4030_mod_iregs __initconst twl4030_mod_regs[] = { - { - .mod_no = TWL4030_MODULE_INT, - .sih_ctrl = TWL4030_INT_PWR_SIH_CTRL, - .reg_cnt = ARRAY_SIZE(twl4030_int_imr_regs), - .imrs = twl4030_int_imr_regs, - .isrs = twl4030_int_isr_regs, - }, - { - .mod_no = TWL4030_MODULE_INTERRUPTS, - .sih_ctrl = TWL4030_INTERRUPTS_BCISIHCTRL, - .reg_cnt = ARRAY_SIZE(twl4030_interrupts_imr_regs), - .imrs = twl4030_interrupts_imr_regs, - .isrs = twl4030_interrupts_isr_regs, - }, - { - .mod_no = TWL4030_MODULE_MADC, - .sih_ctrl = TWL4030_MADC_SIH_CTRL, - .reg_cnt = ARRAY_SIZE(twl4030_madc_imr_regs), - .imrs = twl4030_madc_imr_regs, - .isrs = twl4030_madc_isr_regs, - }, - { - .mod_no = TWL4030_MODULE_KEYPAD, - .sih_ctrl = TWL4030_KEYPAD_KEYP_SIH_CTRL, - .reg_cnt = ARRAY_SIZE(twl4030_keypad_imr_regs), - .imrs = twl4030_keypad_imr_regs, - .isrs = twl4030_keypad_isr_regs, - }, - { - .mod_no = TWL4030_MODULE_GPIO, - .sih_ctrl = REG_GPIO_SIH_CTRL, - .reg_cnt = ARRAY_SIZE(twl4030_gpio_imr_regs), - .imrs = twl4030_gpio_imr_regs, - .isrs = twl4030_gpio_isr_regs, - }, -}; - -/*----------------------------------------------------------------*/ - /* is driver active, bound to a chip? */ static bool inuse; @@ -367,33 +211,6 @@ static struct twl4030mapping twl4030_map[TWL4030_MODULE_LAST + 1] = { /*----------------------------------------------------------------------*/ -/* - * TWL4030 doesn't have PIH mask, hence dummy function for mask - * and unmask of the (eight) interrupts reported at that level ... - * masking is only available from SIH (secondary) modules. - */ - -static void twl4030_i2c_ackirq(unsigned int irq) -{ -} - -static void twl4030_i2c_disableint(unsigned int irq) -{ -} - -static void twl4030_i2c_enableint(unsigned int irq) -{ -} - -static struct irq_chip twl4030_irq_chip = { - .name = "twl4030", - .ack = twl4030_i2c_ackirq, - .mask = twl4030_i2c_disableint, - .unmask = twl4030_i2c_enableint, -}; - -/*----------------------------------------------------------------------*/ - /* Exported Functions */ /** @@ -535,109 +352,6 @@ EXPORT_SYMBOL(twl4030_i2c_read_u8); /*----------------------------------------------------------------------*/ -static unsigned twl4030_irq_base; - -static struct completion irq_event; - -/* - * This thread processes interrupts reported by the Primary Interrupt Handler. - */ -static int twl4030_irq_thread(void *data) -{ - long irq = (long)data; - irq_desc_t *desc = irq_desc + irq; - static unsigned i2c_errors; - const static unsigned max_i2c_errors = 100; - - current->flags |= PF_NOFREEZE; - - while (!kthread_should_stop()) { - int ret; - int module_irq; - u8 pih_isr; - - /* Wait for IRQ, then read PIH irq status (also blocking) */ - wait_for_completion_interruptible(&irq_event); - - ret = twl4030_i2c_read_u8(TWL4030_MODULE_PIH, &pih_isr, - REG_PIH_ISR_P1); - if (ret) { - pr_warning("%s: I2C error %d reading PIH ISR\n", - DRIVER_NAME, ret); - if (++i2c_errors >= max_i2c_errors) { - printk(KERN_ERR "Maximum I2C error count" - " exceeded. Terminating %s.\n", - __func__); - break; - } - complete(&irq_event); - continue; - } - - /* these handlers deal with the relevant SIH irq status */ - local_irq_disable(); - for (module_irq = twl4030_irq_base; - pih_isr; - pih_isr >>= 1, module_irq++) { - if (pih_isr & 0x1) { - irq_desc_t *d = irq_desc + module_irq; - - d->handle_irq(module_irq, d); - } - } - local_irq_enable(); - - desc->chip->unmask(irq); - } - - return 0; -} - -/* - * do_twl4030_irq() is the desc->handle method for the twl4030 interrupt. - * This is a chained interrupt, so there is no desc->action method for it. - * Now we need to query the interrupt controller in the twl4030 to determine - * which module is generating the interrupt request. However, we can't do i2c - * transactions in interrupt context, so we must defer that work to a kernel - * thread. All we do here is acknowledge and mask the interrupt and wakeup - * the kernel thread. - */ -static void do_twl4030_irq(unsigned int irq, irq_desc_t *desc) -{ - const unsigned int cpu = smp_processor_id(); - - /* - * Earlier this was desc->triggered = 1; - */ - desc->status |= IRQ_LEVEL; - - /* - * Acknowledge, clear _AND_ disable the interrupt. - */ - desc->chip->ack(irq); - - if (!desc->depth) { - kstat_cpu(cpu).irqs[irq]++; - - complete(&irq_event); - } -} - -static struct task_struct * __init start_twl4030_irq_thread(long irq) -{ - struct task_struct *thread; - - init_completion(&irq_event); - thread = kthread_run(twl4030_irq_thread, (void *)irq, "twl4030-irq"); - if (!thread) - pr_err("%s: could not create twl4030 irq %ld thread!\n", - DRIVER_NAME, irq); - - return thread; -} - -/*----------------------------------------------------------------------*/ - static int add_children(struct twl4030_platform_data *pdata) { struct platform_device *pdev = NULL; @@ -965,123 +679,17 @@ static void __init clocks_init(void) /*----------------------------------------------------------------------*/ -/** - * twl4030_i2c_clear_isr - clear TWL4030 SIH ISR regs via read + write - * @mod_no: TWL4030 module number - * @reg: register index to clear - * @cor: value of the _SIH_CTRL.COR bit (1 or 0) - * - * Either reads (cor == 1) or writes (cor == 0) to a TWL4030 interrupt - * status register to ensure that any prior interrupts are cleared. - * Returns the status from the I2C read operation. - */ -static int __init twl4030_i2c_clear_isr(u8 mod_no, u8 reg, u8 cor) -{ - u8 tmp; - - return (cor) ? twl4030_i2c_read_u8(mod_no, &tmp, reg) : - twl4030_i2c_write_u8(mod_no, 0xff, reg); -} - -/** - * twl4030_read_cor_bit - are TWL module ISRs cleared by reads or writes? - * @mod_no: TWL4030 module number - * @reg: register index to clear - * - * Returns 1 if the TWL4030 SIH interrupt status registers (ISRs) for - * the specified TWL module are cleared by reads, or 0 if cleared by - * writes. - */ -static int twl4030_read_cor_bit(u8 mod_no, u8 reg) -{ - u8 tmp = 0; - - WARN_ON(twl4030_i2c_read_u8(mod_no, &tmp, reg) < 0); - - tmp &= TWL4030_SIH_CTRL_COR_MASK; - tmp >>= __ffs(TWL4030_SIH_CTRL_COR_MASK); - - return tmp; -} - -/** - * twl4030_mask_clear_intrs - mask and clear all TWL4030 interrupts - * @t: pointer to twl4030_mod_iregs array - * @t_sz: ARRAY_SIZE(t) (starting at 1) - * - * Mask all TWL4030 interrupt mask registers (IMRs) and clear all - * interrupt status registers (ISRs). No return value, but will WARN if - * any I2C operations fail. - */ -static void __init twl4030_mask_clear_intrs(const struct twl4030_mod_iregs *t, - const u8 t_sz) -{ - int i, j; - - /* - * N.B. - further efficiency is possible here. Eight I2C - * operations on BCI and GPIO modules are avoidable if I2C - * burst read/write transactions were implemented. Would - * probably save about 1ms of boot time and a small amount of - * power. - */ - for (i = 0; i < t_sz; i++) { - const struct twl4030_mod_iregs tmr = t[i]; - int cor; - - /* Are ISRs cleared by reads or writes? */ - cor = twl4030_read_cor_bit(tmr.mod_no, tmr.sih_ctrl); - - for (j = 0; j < tmr.reg_cnt; j++) { - - /* Mask interrupts at the TWL4030 */ - WARN_ON(twl4030_i2c_write_u8(tmr.mod_no, 0xff, - tmr.imrs[j]) < 0); - - /* Clear TWL4030 ISRs */ - WARN_ON(twl4030_i2c_clear_isr(tmr.mod_no, - tmr.isrs[j], cor) < 0); - } - } -} - - -static void twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end) -{ - int i; - - /* - * Mask and clear all TWL4030 interrupts since initially we do - * not have any TWL4030 module interrupt handlers present - */ - twl4030_mask_clear_intrs(twl4030_mod_regs, - ARRAY_SIZE(twl4030_mod_regs)); - - twl4030_irq_base = irq_base; - - /* install an irq handler for each of the PIH modules */ - for (i = irq_base; i < irq_end; i++) { - set_irq_chip_and_handler(i, &twl4030_irq_chip, - handle_simple_irq); - activate_irq(i); - } - - /* install an irq handler to demultiplex the TWL4030 interrupt */ - set_irq_data(irq_num, start_twl4030_irq_thread(irq_num)); - set_irq_chained_handler(irq_num, do_twl4030_irq); -} - -/*----------------------------------------------------------------------*/ +int twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end); +int twl_exit_irq(void); static int twl4030_remove(struct i2c_client *client) { unsigned i; + int status; - /* FIXME undo twl_init_irq() */ - if (twl4030_irq_base) { - dev_err(&client->dev, "can't yet clean up IRQs?\n"); - return -ENOSYS; - } + status = twl_exit_irq(); + if (status < 0) + return status; for (i = 0; i < TWL4030_NUM_SLAVES; i++) { struct twl4030_client *twl = &twl4030_modules[i]; @@ -1112,7 +720,7 @@ twl4030_probe(struct i2c_client *client, const struct i2c_device_id *id) return -EIO; } - if (inuse || twl4030_irq_base) { + if (inuse) { dev_dbg(&client->dev, "driver is already in use\n"); return -EBUSY; } @@ -1146,7 +754,9 @@ twl4030_probe(struct i2c_client *client, const struct i2c_device_id *id) if (client->irq && pdata->irq_base && pdata->irq_end > pdata->irq_base) { - twl_init_irq(client->irq, pdata->irq_base, pdata->irq_end); + status = twl_init_irq(client->irq, pdata->irq_base, pdata->irq_end); + if (status < 0) + goto fail; dev_info(&client->dev, "IRQ %d chains IRQs %d..%d\n", client->irq, pdata->irq_base, pdata->irq_end - 1); } diff --git a/drivers/mfd/twl4030-irq.c b/drivers/mfd/twl4030-irq.c new file mode 100644 index 00000000000..e849bc0c65c --- /dev/null +++ b/drivers/mfd/twl4030-irq.c @@ -0,0 +1,408 @@ +/* + * twl4030-irq.c - TWL4030/TPS659x0 irq support + * + * Copyright (C) 2005-2006 Texas Instruments, Inc. + * + * Modifications to defer interrupt handling to a kernel thread: + * Copyright (C) 2006 MontaVista Software, Inc. + * + * Based on tlv320aic23.c: + * Copyright (c) by Kai Svahn + * + * Code cleanup and modifications to IRQ handler. + * by syed khasim + * + * 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 +#include +#include +#include + +#include + + +static inline void activate_irq(int irq) +{ +#ifdef CONFIG_ARM + /* ARM requires an extra step to clear IRQ_NOREQUEST, which it + * sets on behalf of every irq_chip. Also sets IRQ_NOPROBE. + */ + set_irq_flags(irq, IRQF_VALID); +#else + /* same effect on other architectures */ + set_irq_noprobe(irq); +#endif +} + +/* PIH register offsets */ +#define REG_PIH_ISR_P1 0x01 +#define REG_PIH_ISR_P2 0x02 +#define REG_PIH_SIR 0x03 /* for testing */ + +/*----------------------------------------------------------------------*/ + +/** + * struct twl4030_mod_iregs - TWL module IMR/ISR regs to mask/clear at init + * @mod_no: TWL4030 module number (e.g., TWL4030_MODULE_GPIO) + * @sih_ctrl: address of module SIH_CTRL register + * @reg_cnt: number of IMR/ISR regs + * @imrs: pointer to array of TWL module interrupt mask register indices + * @isrs: pointer to array of TWL module interrupt status register indices + * + * Ties together TWL4030 modules and lists of IMR/ISR registers to mask/clear + * during twl_init_irq(). + */ +struct twl4030_mod_iregs { + const u8 mod_no; + const u8 sih_ctrl; + const u8 reg_cnt; + const u8 *imrs; + const u8 *isrs; +}; + +/* TWL4030 INT module interrupt mask registers */ +static const u8 __initconst twl4030_int_imr_regs[] = { + TWL4030_INT_PWR_IMR1, + TWL4030_INT_PWR_IMR2, +}; + +/* TWL4030 INT module interrupt status registers */ +static const u8 __initconst twl4030_int_isr_regs[] = { + TWL4030_INT_PWR_ISR1, + TWL4030_INT_PWR_ISR2, +}; + +/* TWL4030 INTERRUPTS module interrupt mask registers */ +static const u8 __initconst twl4030_interrupts_imr_regs[] = { + TWL4030_INTERRUPTS_BCIIMR1A, + TWL4030_INTERRUPTS_BCIIMR1B, + TWL4030_INTERRUPTS_BCIIMR2A, + TWL4030_INTERRUPTS_BCIIMR2B, +}; + +/* TWL4030 INTERRUPTS module interrupt status registers */ +static const u8 __initconst twl4030_interrupts_isr_regs[] = { + TWL4030_INTERRUPTS_BCIISR1A, + TWL4030_INTERRUPTS_BCIISR1B, + TWL4030_INTERRUPTS_BCIISR2A, + TWL4030_INTERRUPTS_BCIISR2B, +}; + +/* TWL4030 MADC module interrupt mask registers */ +static const u8 __initconst twl4030_madc_imr_regs[] = { + TWL4030_MADC_IMR1, + TWL4030_MADC_IMR2, +}; + +/* TWL4030 MADC module interrupt status registers */ +static const u8 __initconst twl4030_madc_isr_regs[] = { + TWL4030_MADC_ISR1, + TWL4030_MADC_ISR2, +}; + +/* TWL4030 keypad module interrupt mask registers */ +static const u8 __initconst twl4030_keypad_imr_regs[] = { + TWL4030_KEYPAD_KEYP_IMR1, + TWL4030_KEYPAD_KEYP_IMR2, +}; + +/* TWL4030 keypad module interrupt status registers */ +static const u8 __initconst twl4030_keypad_isr_regs[] = { + TWL4030_KEYPAD_KEYP_ISR1, + TWL4030_KEYPAD_KEYP_ISR2, +}; + +/* TWL4030 GPIO module interrupt mask registers */ +static const u8 __initconst twl4030_gpio_imr_regs[] = { + REG_GPIO_IMR1A, + REG_GPIO_IMR1B, + REG_GPIO_IMR2A, + REG_GPIO_IMR2B, + REG_GPIO_IMR3A, + REG_GPIO_IMR3B, +}; + +/* TWL4030 GPIO module interrupt status registers */ +static const u8 __initconst twl4030_gpio_isr_regs[] = { + REG_GPIO_ISR1A, + REG_GPIO_ISR1B, + REG_GPIO_ISR2A, + REG_GPIO_ISR2B, + REG_GPIO_ISR3A, + REG_GPIO_ISR3B, +}; + +/* TWL4030 modules that have IMR/ISR registers that must be masked/cleared */ +static const struct twl4030_mod_iregs __initconst twl4030_mod_regs[] = { + { + .mod_no = TWL4030_MODULE_INT, + .sih_ctrl = TWL4030_INT_PWR_SIH_CTRL, + .reg_cnt = ARRAY_SIZE(twl4030_int_imr_regs), + .imrs = twl4030_int_imr_regs, + .isrs = twl4030_int_isr_regs, + }, + { + .mod_no = TWL4030_MODULE_INTERRUPTS, + .sih_ctrl = TWL4030_INTERRUPTS_BCISIHCTRL, + .reg_cnt = ARRAY_SIZE(twl4030_interrupts_imr_regs), + .imrs = twl4030_interrupts_imr_regs, + .isrs = twl4030_interrupts_isr_regs, + }, + { + .mod_no = TWL4030_MODULE_MADC, + .sih_ctrl = TWL4030_MADC_SIH_CTRL, + .reg_cnt = ARRAY_SIZE(twl4030_madc_imr_regs), + .imrs = twl4030_madc_imr_regs, + .isrs = twl4030_madc_isr_regs, + }, + { + .mod_no = TWL4030_MODULE_KEYPAD, + .sih_ctrl = TWL4030_KEYPAD_KEYP_SIH_CTRL, + .reg_cnt = ARRAY_SIZE(twl4030_keypad_imr_regs), + .imrs = twl4030_keypad_imr_regs, + .isrs = twl4030_keypad_isr_regs, + }, + { + .mod_no = TWL4030_MODULE_GPIO, + .sih_ctrl = REG_GPIO_SIH_CTRL, + .reg_cnt = ARRAY_SIZE(twl4030_gpio_imr_regs), + .imrs = twl4030_gpio_imr_regs, + .isrs = twl4030_gpio_isr_regs, + }, +}; + +/*----------------------------------------------------------------------*/ + +static unsigned twl4030_irq_base; + +static struct completion irq_event; + +/* + * This thread processes interrupts reported by the Primary Interrupt Handler. + */ +static int twl4030_irq_thread(void *data) +{ + long irq = (long)data; + irq_desc_t *desc = irq_desc + irq; + static unsigned i2c_errors; + const static unsigned max_i2c_errors = 100; + + current->flags |= PF_NOFREEZE; + + while (!kthread_should_stop()) { + int ret; + int module_irq; + u8 pih_isr; + + /* Wait for IRQ, then read PIH irq status (also blocking) */ + wait_for_completion_interruptible(&irq_event); + + ret = twl4030_i2c_read_u8(TWL4030_MODULE_PIH, &pih_isr, + REG_PIH_ISR_P1); + if (ret) { + pr_warning("twl4030: I2C error %d reading PIH ISR\n", + ret); + if (++i2c_errors >= max_i2c_errors) { + printk(KERN_ERR "Maximum I2C error count" + " exceeded. Terminating %s.\n", + __func__); + break; + } + complete(&irq_event); + continue; + } + + /* these handlers deal with the relevant SIH irq status */ + local_irq_disable(); + for (module_irq = twl4030_irq_base; + pih_isr; + pih_isr >>= 1, module_irq++) { + if (pih_isr & 0x1) { + irq_desc_t *d = irq_desc + module_irq; + + /* These can't be masked ... always warn + * if we get any surprises. + */ + if (d->status & IRQ_DISABLED) + note_interrupt(module_irq, d, + IRQ_NONE); + else + d->handle_irq(module_irq, d); + } + } + local_irq_enable(); + + desc->chip->unmask(irq); + } + + return 0; +} + +/* + * handle_twl4030_pih() is the desc->handle method for the twl4030 interrupt. + * This is a chained interrupt, so there is no desc->action method for it. + * Now we need to query the interrupt controller in the twl4030 to determine + * which module is generating the interrupt request. However, we can't do i2c + * transactions in interrupt context, so we must defer that work to a kernel + * thread. All we do here is acknowledge and mask the interrupt and wakeup + * the kernel thread. + */ +static void handle_twl4030_pih(unsigned int irq, irq_desc_t *desc) +{ + /* Acknowledge, clear *AND* mask the interrupt... */ + desc->chip->ack(irq); + complete(&irq_event); +} + +static struct task_struct *start_twl4030_irq_thread(long irq) +{ + struct task_struct *thread; + + init_completion(&irq_event); + thread = kthread_run(twl4030_irq_thread, (void *)irq, "twl4030-irq"); + if (!thread) + pr_err("twl4030: could not create irq %ld thread!\n", irq); + + return thread; +} + +/*----------------------------------------------------------------------*/ + +/** + * twl4030_i2c_clear_isr - clear TWL4030 SIH ISR regs via read + write + * @mod_no: TWL4030 module number + * @reg: register index to clear + * @cor: value of the _SIH_CTRL.COR bit (1 or 0) + * + * Either reads (cor == 1) or writes (cor == 0) to a TWL4030 interrupt + * status register to ensure that any prior interrupts are cleared. + * Returns the status from the I2C read operation. + */ +static int __init twl4030_i2c_clear_isr(u8 mod_no, u8 reg, u8 cor) +{ + u8 tmp; + + return (cor) ? twl4030_i2c_read_u8(mod_no, &tmp, reg) : + twl4030_i2c_write_u8(mod_no, 0xff, reg); +} + +/** + * twl4030_read_cor_bit - are TWL module ISRs cleared by reads or writes? + * @mod_no: TWL4030 module number + * @reg: register index to clear + * + * Returns 1 if the TWL4030 SIH interrupt status registers (ISRs) for + * the specified TWL module are cleared by reads, or 0 if cleared by + * writes. + */ +static int twl4030_read_cor_bit(u8 mod_no, u8 reg) +{ + u8 tmp = 0; + + WARN_ON(twl4030_i2c_read_u8(mod_no, &tmp, reg) < 0); + + tmp &= TWL4030_SIH_CTRL_COR_MASK; + tmp >>= __ffs(TWL4030_SIH_CTRL_COR_MASK); + + return tmp; +} + +/** + * twl4030_mask_clear_intrs - mask and clear all TWL4030 interrupts + * @t: pointer to twl4030_mod_iregs array + * @t_sz: ARRAY_SIZE(t) (starting at 1) + * + * Mask all TWL4030 interrupt mask registers (IMRs) and clear all + * interrupt status registers (ISRs). No return value, but will WARN if + * any I2C operations fail. + */ +static void __init twl4030_mask_clear_intrs(const struct twl4030_mod_iregs *t, + const u8 t_sz) +{ + int i, j; + + /* + * N.B. - further efficiency is possible here. Eight I2C + * operations on BCI and GPIO modules are avoidable if I2C + * burst read/write transactions were implemented. Would + * probably save about 1ms of boot time and a small amount of + * power. + */ + for (i = 0; i < t_sz; i++) { + const struct twl4030_mod_iregs tmr = t[i]; + int cor; + + /* Are ISRs cleared by reads or writes? */ + cor = twl4030_read_cor_bit(tmr.mod_no, tmr.sih_ctrl); + + for (j = 0; j < tmr.reg_cnt; j++) { + + /* Mask interrupts at the TWL4030 */ + WARN_ON(twl4030_i2c_write_u8(tmr.mod_no, 0xff, + tmr.imrs[j]) < 0); + + /* Clear TWL4030 ISRs */ + WARN_ON(twl4030_i2c_clear_isr(tmr.mod_no, + tmr.isrs[j], cor) < 0); + } + } +} + + +int twl_init_irq(int irq_num, unsigned irq_base, unsigned irq_end) +{ + static struct irq_chip twl4030_irq_chip; + + int i; + + /* + * Mask and clear all TWL4030 interrupts since initially we do + * not have any TWL4030 module interrupt handlers present + */ + twl4030_mask_clear_intrs(twl4030_mod_regs, + ARRAY_SIZE(twl4030_mod_regs)); + + twl4030_irq_base = irq_base; + + /* install an irq handler for each of the SIH modules; + * clone dummy irq_chip since PIH can't *do* anything + */ + twl4030_irq_chip = dummy_irq_chip; + twl4030_irq_chip.name = "twl4030"; + + for (i = irq_base; i < irq_end; i++) { + set_irq_chip_and_handler(i, &twl4030_irq_chip, + handle_simple_irq); + activate_irq(i); + } + + /* install an irq handler to demultiplex the TWL4030 interrupt */ + set_irq_data(irq_num, start_twl4030_irq_thread(irq_num)); + set_irq_chained_handler(irq_num, handle_twl4030_pih); + + return 0; +} + +int twl_exit_irq(void) +{ + /* FIXME undo twl_init_irq() */ + if (twl4030_irq_base) { + pr_err("twl4030: can't yet clean up IRQs?\n"); + return -ENOSYS; + } + return 0; +} -- 2.41.1