TWL4030: use *_SIH_CTRL.COR bit to determine whether to read or write ISR to clear From: Paul Walmsley TWL4030 interrupt status register bits can be cleared in one of two ways: either by reading from the register, or by writing a 1 to the appropriate bit(s) in the register. This behavior can be altered at any time by the _SIH_CTRL.COR register bit ("clear-on-read"). The TWL4030 TRM is deeply confused as to whether COR=1 means that the registers are cleared on reads, or cleared on writes. Peter De Schrijver confirms that COR=1 means that the registers are cleared on read. So, for each TWL4030 SIH, check the value of the *_SIH_CTRL.COR bit, and if it is 1, use reads to clear the ISRs; if it is 0, use writes. Also, use WARN_ON() to warn if the read/write failed, and don't skip the rest of the initialization on failure either. Thanks to Peter for his help with this patch. Signed-off-by: Paul Walmsley --- drivers/i2c/chips/twl4030-core.c | 183 ++++++++++++++++++++++---------------- 1 files changed, 106 insertions(+), 77 deletions(-) diff --git a/drivers/i2c/chips/twl4030-core.c b/drivers/i2c/chips/twl4030-core.c index 9d93524..eae0634 100644 --- a/drivers/i2c/chips/twl4030-core.c +++ b/drivers/i2c/chips/twl4030-core.c @@ -133,6 +133,16 @@ /* on I2C-1 for 2430SDP */ #define CONFIG_I2C_TWL4030_ID 1 +/* SIH_CTRL registers */ +#define TWL4030_INT_PWR_SIH_CTRL 0x07 +#define TWL4030_INTERRUPTS_BCISIHCTRL 0x0d +#define TWL4030_MADC_MADC_SIH_CTRL 0x67 +#define TWL4030_KEYPAD_KEYP_SIH_CTRL 0x17 +#define TWL4030_GPIO_GPIO_SIH_CTRL 0x2d + +#define TWL4030_SIH_CTRL_COR_MASK (1 << 2) + + /* Helper functions */ static int twl4030_detect_client(struct i2c_adapter *adapter, unsigned char sid); @@ -712,13 +722,61 @@ static int power_companion_init(void) return e; } +/** + * 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 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; +} + static void twl_init_irq(void) { int i = 0; int res = 0; + int cor; char *msg = "Unable to register interrupt subsystem"; unsigned int irq_num; + /* + * For each TWL4030 module with ISR/IMR registers, mask all + * interrupts and then clear any existing interrupt status bits, + * since we initially do not have any TWL4030 module interrupt + * handlers present. + */ + + /* PWR_IMR1 */ res = twl4030_i2c_write_u8(TWL4030_MODULE_INT, 0xFF, 0x1); if (res < 0) { @@ -734,20 +792,18 @@ static void twl_init_irq(void) } /* Clear off any other pending interrupts on power */ + + /* Are PWR interrupt status bits cleared by reads or writes? */ + cor = twl4030_read_cor_bit(TWL4030_MODULE_INT, + TWL4030_INT_PWR_SIH_CTRL); + WARN_ON(cor < 0); + /* PWR_ISR1 */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_INT, 0xFF, 0x00); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_INT, 0x00, cor) < 0); /* PWR_ISR2 */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_INT, 0xFF, 0x02); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } - /* POWER HACK (END) */ + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_INT, 0x02, cor) < 0); + /* Slave address 0x4A */ /* BCIIMR1A */ @@ -778,33 +834,22 @@ static void twl_init_irq(void) return; } + /* Are BCI interrupt status bits cleared by reads or writes? */ + cor = twl4030_read_cor_bit(TWL4030_MODULE_INTERRUPTS, + TWL4030_INTERRUPTS_BCISIHCTRL); + WARN_ON(cor < 0); + /* BCIISR1A */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xFF, 0x0); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_INTERRUPTS, 0x0, cor) < 0); /* BCIISR2A */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xFF, 0x1); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_INTERRUPTS, 0x1, cor) < 0); /* BCIISR1B */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xFF, 0x4); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_INTERRUPTS, 0x4, cor) < 0); /* BCIISR2B */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_INTERRUPTS, 0xFF, 0x5); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_INTERRUPTS, 0x5, cor) < 0); /* MAD C */ /* MADC_IMR1 */ @@ -821,19 +866,16 @@ static void twl_init_irq(void) return; } + /* Are MADC interrupt status bits cleared by reads or writes? */ + cor = twl4030_read_cor_bit(TWL4030_MODULE_MADC, + TWL4030_MADC_MADC_SIH_CTRL); + WARN_ON(cor < 0); + /* MADC_ISR1 */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_MADC, 0xFF, 0x61); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_MADC, 0x61, cor) < 0); /* MADC_ISR2 */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_MADC, 0xFF, 0x63); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_MADC, 0x63, cor) < 0); /* key Pad */ /* KEYPAD - IMR1 */ @@ -842,12 +884,15 @@ static void twl_init_irq(void) pr_err("%s[%d][%d]\n", msg, res, __LINE__); return; } - { - u8 clear; - /* Clear ISR */ - twl4030_i2c_read_u8(TWL4030_MODULE_KEYPAD, &clear, 0x11); - twl4030_i2c_read_u8(TWL4030_MODULE_KEYPAD, &clear, 0x11); - } + + /* Are keypad interrupt status bits cleared by reads or writes? */ + cor = twl4030_read_cor_bit(TWL4030_MODULE_KEYPAD, + TWL4030_KEYPAD_KEYP_SIH_CTRL); + WARN_ON(cor < 0); + + /* KEYPAD - ISR1 */ + /* XXX does this still need to be done twice for some reason? */ + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_KEYPAD, 0x11, cor) < 0); /* KEYPAD - IMR2 */ res = twl4030_i2c_write_u8(TWL4030_MODULE_KEYPAD, 0xFF, (0x14)); @@ -856,6 +901,9 @@ static void twl_init_irq(void) return; } + /* KEYPAD - ISR2 */ + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_KEYPAD, 0x13, cor) < 0); + /* Slave address 0x49 */ /* GPIO_IMR1A */ res = twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, 0xFF, (0x1C)); @@ -899,47 +947,28 @@ static void twl_init_irq(void) return; } + /* Are GPIO interrupt status bits cleared by reads or writes? */ + cor = twl4030_read_cor_bit(TWL4030_MODULE_GPIO, + TWL4030_GPIO_GPIO_SIH_CTRL); + WARN_ON(cor < 0); + /* GPIO_ISR1A */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, 0xff, 0x19); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_GPIO, 0x19, cor) < 0); /* GPIO_ISR2A */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, 0xff, 0x1a); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_GPIO, 0x1a, cor) < 0); /* GPIO_ISR3A */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, 0xff, 0x1b); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_GPIO, 0x1b, cor) < 0); /* GPIO_ISR1B */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, 0xff, 0x1f); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_GPIO, 0x1f, cor) < 0); /* GPIO_ISR2B */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, 0xff, 0x20); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_GPIO, 0x20, cor) < 0); /* GPIO_ISR3B */ - res = twl4030_i2c_write_u8(TWL4030_MODULE_GPIO, 0xff, 0x21); - if (res < 0) { - pr_err("%s[%d][%d]\n", msg, res, __LINE__); - return; - } + WARN_ON(twl4030_i2c_clear_isr(TWL4030_MODULE_GPIO, 0x21, cor) < 0); /* install an irq handler for each of the PIH modules */ for (i = TWL4030_IRQ_BASE; i < TWL4030_IRQ_END; i++) {