From 0324bf59a8810cadf35d67f71f5ee409834ec4ee Mon Sep 17 00:00:00 2001 From: Amaury Pouly Date: Tue, 4 Feb 2014 00:23:35 +0100 Subject: imx233: make button-lradc drive able to handle VDDIO derived values In most devices, the button ladder is not actually derived from VDDIO but from a constant voltage source, making it very easy to read it. However on some devices like ther ZEN X-Fi Style, the ladder is wired to VDDIO we can be changed so it's crucial that the button driver correctly scales the values wrt VDDIO. Change-Id: Ifc11abe2838fa7d16d0d60ecd96964a8dc5ea6d7 --- firmware/target/arm/imx233/button-lradc-imx233.c | 73 ++++++++++++++++++---- firmware/target/arm/imx233/button-lradc-imx233.h | 19 ++++++ .../target/arm/imx233/creative-zen/button-target.h | 11 ++++ firmware/target/arm/imx233/lradc-imx233.h | 3 + 4 files changed, 93 insertions(+), 13 deletions(-) (limited to 'firmware') diff --git a/firmware/target/arm/imx233/button-lradc-imx233.c b/firmware/target/arm/imx233/button-lradc-imx233.c index 6bb7f9babe..141281041b 100644 --- a/firmware/target/arm/imx233/button-lradc-imx233.c +++ b/firmware/target/arm/imx233/button-lradc-imx233.c @@ -58,6 +58,10 @@ /* delay's delay */ #define DELAY (LRADC_DELAY_FREQ / RATE / SAMPLES) +#ifdef IMX233_BUTTON_LRADC_VDDIO +#define HAS_VDDIO +#endif + static int button_delay; static int button_chan; static int button_val[2]; @@ -65,9 +69,18 @@ static int button_idx; static int button_mask; static int table_size; static int raw_val; +#ifdef HAS_VDDIO +static int vddio_chan; +static int vddio_val; +#endif +static int delay_chan_mask; // trigger channel mask +static int irq_chan_mask; // triggered channel mask static int button_find(int val) { +#ifdef IMX233_BUTTON_LRADC_VDDIO + val = (val * IMX233_BUTTON_LRADC_VDDIO) / vddio_val; +#endif // shortcuts struct imx233_button_lradc_mapping_t *table = imx233_button_lradc_mapping; /* FIXME use a dichotomy */ @@ -91,18 +104,35 @@ static int button_find(int val) static void button_lradc_irq(int chan) { - (void) chan; - /* read value, kick channel */ - raw_val = imx233_lradc_read_channel(button_chan) / SAMPLES; - imx233_lradc_clear_channel(button_chan); - imx233_lradc_setup_channel(button_chan, true, true, SAMPLES - 1, LRADC_SRC(CHAN)); - imx233_lradc_setup_delay(button_delay, 1 << button_chan, 0, SAMPLES - 1, DELAY); - imx233_lradc_kick_delay(button_delay); - /* compute mask, compare to previous one */ - button_val[button_idx] = button_find(raw_val); - button_idx = 1 - button_idx; - if(button_val[0] == button_val[1]) - button_mask = button_val[0]; + /* read value, clear channel */ +#ifdef HAS_VDDIO + if(chan == vddio_chan) + { + vddio_val = imx233_lradc_read_channel(vddio_chan) / SAMPLES; + vddio_val *= 2; /* VDDIO channel has internal divider */ + imx233_lradc_clear_channel(vddio_chan); + imx233_lradc_setup_channel(vddio_chan, true, true, SAMPLES - 1, LRADC_SRC_VDDIO); + } +#endif + if(chan == button_chan) + { + raw_val = imx233_lradc_read_channel(button_chan) / SAMPLES; + imx233_lradc_clear_channel(button_chan); + imx233_lradc_setup_channel(button_chan, true, true, SAMPLES - 1, LRADC_SRC(CHAN)); + } + /* record irq, trigger delay if all IRQs have been fired */ + irq_chan_mask |= 1 << chan; + if(irq_chan_mask == delay_chan_mask) + { + irq_chan_mask = 0; + imx233_lradc_setup_delay(button_delay, delay_chan_mask, 0, SAMPLES - 1, DELAY); + imx233_lradc_kick_delay(button_delay); + /* compute mask, compare to previous one */ + button_val[button_idx] = button_find(raw_val); + button_idx = 1 - button_idx; + if(button_val[0] == button_val[1]) + button_mask = button_val[0]; + } } void imx233_button_lradc_init(void) @@ -118,9 +148,19 @@ void imx233_button_lradc_init(void) if(button_delay < 0) panicf("Cannot get delay for button-lradc"); imx233_lradc_setup_channel(button_chan, true, true, SAMPLES - 1, LRADC_SRC(CHAN)); - imx233_lradc_setup_delay(button_delay, 1 << button_chan, 0, SAMPLES - 1, DELAY); imx233_lradc_enable_channel_irq(button_chan, true); imx233_lradc_set_channel_irq_callback(button_chan, button_lradc_irq); + delay_chan_mask = 1 << button_chan; +#ifdef HAS_VDDIO + vddio_chan = imx233_lradc_acquire_channel(LRADC_SRC_VDDIO, TIMEOUT_NOBLOCK); + if(vddio_chan < 0) + panicf("Cannot get vddio channel for button-lradc"); + imx233_lradc_setup_channel(vddio_chan, true, true, SAMPLES - 1, LRADC_SRC_VDDIO); + imx233_lradc_enable_channel_irq(vddio_chan, true); + imx233_lradc_set_channel_irq_callback(vddio_chan, button_lradc_irq); + delay_chan_mask |= 1 << vddio_chan; +#endif + imx233_lradc_setup_delay(button_delay, delay_chan_mask, 0, SAMPLES - 1, DELAY); imx233_lradc_kick_delay(button_delay); #if defined(HAS_BUTTON_HOLD) && IMX233_BUTTON_LRADC_HOLD_DET == BLH_GPIO imx233_pinctrl_acquire(BLH_GPIO_BANK, BLH_GPIO_PIN, "button_lradc_hold"); @@ -164,3 +204,10 @@ int imx233_button_lradc_read_raw(void) { return raw_val; } + +#ifdef HAS_VDDIO +int imx233_button_lradc_read_vddio(void) +{ + return vddio_val; // the VDDIO channel has an internal divider +} +#endif diff --git a/firmware/target/arm/imx233/button-lradc-imx233.h b/firmware/target/arm/imx233/button-lradc-imx233.h index eac5517adf..d96823fcdc 100644 --- a/firmware/target/arm/imx233/button-lradc-imx233.h +++ b/firmware/target/arm/imx233/button-lradc-imx233.h @@ -30,7 +30,19 @@ * - imx233_button_lradc_mapping: target-defined table of adc values and mapping * - IMX233_BUTTON_LRADC_CHANNEL: lradc channel to use * - IMX233_BUTTON_LRADC_HOLD_DET: define hold detection method (ignored if !HAS_BUTTON_HOLD) + * - IMX233_BUTTON_LRADC_MODE: define the button lradc mode * + * The LRADC code supports two modes of operations: VDDIO relative or absolute. + * In the (default) absolute value mode, the LRADC channel is sampled and its value + * is compared to the one in the imx233_button_lradc_mapping table. This is + * appropriate when the resistor ladder is derived from a fixed voltage. + * In the VDDIO relative mode, the values in imx233_button_lradc_mapping are + * the values for a specific value of VDDIO which is given by + * IMX233_BUTTON_LRADC_VDDIO. In this mode, the code will also sample VDDIO + * and do the following comparison: + * lradc_value <=? imx233_button_lradc_mapping[i] * vddio_ref / vddio_value + * where vddio_ref is IMX233_BUTTON_LRADC_VDDIO. + * * The available values of IMX233_BUTTON_LRADC_HOLD are: * - BLH_ADC: detect hold using adc * - BLH_EXT: target button driver implements imx233_button_lradc_hold() using @@ -40,6 +52,10 @@ * + BLH_GPIO_PIN: pin in bank * + BLH_GPIO_INVERTED: define if inverted, default is active high * + BLH_GPIO_PULLUP: define if pins needs pullup + * + * WARNING + * There must always be entry in imx233_button_lradc_mapping whose value is the steady + * value of the channel when no button is pressed, and which maps to no button (.btn = 0) */ /* hold detect method */ @@ -74,5 +90,8 @@ int imx233_button_lradc_read(int others); bool imx233_button_lradc_hold(void); #endif int imx233_button_lradc_read_raw(void); // return raw adc value +#ifdef IMX233_BUTTON_LRADC_VDDIO +int imx233_button_lradc_read_vddio(void); +#endif #endif /* __button_lradc_imx233__ */ diff --git a/firmware/target/arm/imx233/creative-zen/button-target.h b/firmware/target/arm/imx233/creative-zen/button-target.h index 65521d66e4..e9a3ac5ab7 100644 --- a/firmware/target/arm/imx233/creative-zen/button-target.h +++ b/firmware/target/arm/imx233/creative-zen/button-target.h @@ -25,11 +25,22 @@ bool button_debug_screen(void); +/* HOLD button */ #if !defined(CREATIVE_ZENXFISTYLE) #define HAS_BUTTON_HOLD #define IMX233_BUTTON_LRADC_HOLD_DET BLH_ADC #endif +/* VDDIO value */ +#if defined(CREATIVE_ZENXFISTYLE) +#define IMX233_BUTTON_LRADC_VDDIO 3660 +#elif defined(CREATIVE_ZEN) +#define IMX233_BUTTON_LRADC_VDDIO 3480 +#elif defined(CREATIVE_ZENXFI) +#define IMX233_BUTTON_LRADC_VDDIO 3500 +#endif + +/* LRADC channel */ #if defined(CREATIVE_ZENXFISTYLE) #define IMX233_BUTTON_LRADC_CHANNEL 2 #else diff --git a/firmware/target/arm/imx233/lradc-imx233.h b/firmware/target/arm/imx233/lradc-imx233.h index f274db3520..e7853b97a5 100644 --- a/firmware/target/arm/imx233/lradc-imx233.h +++ b/firmware/target/arm/imx233/lradc-imx233.h @@ -65,6 +65,9 @@ /* frequency of the delay counter */ #define LRADC_DELAY_FREQ 2000 +/* maximum value of a sample (without accumulation), defines the precision */ +#define LRADC_MAX_VALUE 4096 + typedef void (*lradc_irq_fn_t)(int chan); void imx233_lradc_init(void); -- cgit v1.2.3