Hello, I have developed basic ADC driver for BBB and tested it on hardware by giving dgnd to the AIN pin and getting 0-4 value for that.
Herewith I am attaching patch for the same. Kindly review it. Your suggestion(s)/ comment(s) are welcomed. Also I updated my GitHub <https://github.com/ketul93/RTEMS-on-BBB/tree/master/ADC-TEST> for ADC where working .img or .exe file can be found. And the whole code can be found on RTEMS Repo <https://github.com/ketul93/rtems>. Also attaching the screenshot of the working code on my pc. :) Next week also planing to have a video of ADC demo. Thanks. Best Regards, Ketul
diff --git a/c/src/lib/libbsp/arm/beagle/Makefile.am b/c/src/lib/libbsp/arm/beagle/Makefile.am index 6b876dd..debcc88 100644 --- a/c/src/lib/libbsp/arm/beagle/Makefile.am +++ b/c/src/lib/libbsp/arm/beagle/Makefile.am @@ -115,6 +115,9 @@ libbsp_a_SOURCES += ../../shared/console.c \ # GPIO libbsp_a_SOURCES += gpio/gpio.c +#ADC +libbsp_a_SOURCES += adc/adc.c + # I2C libbsp_a_SOURCES += misc/i2c.c diff --git a/c/src/lib/libbsp/arm/beagle/adc/adc.c b/c/src/lib/libbsp/arm/beagle/adc/adc.c new file mode 100644 index 0000000..63c3307 --- /dev/null +++ b/c/src/lib/libbsp/arm/beagle/adc/adc.c @@ -0,0 +1,97 @@ +/** + * @file + * + * @ingroup arm_beagle + * + * @brief ADC definitions. + */ + +/** + * Copyright (c) 2015 Ketul Shah <ketulshah1993 at gmail.com> + + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ + +#include <libcpu/am335x.h> +#include <rtems.h> +#include <rtems/gpio.h> +#include <bsp/irq.h> +#include <bsp/beagleboneblack.h> +#include <bsp.h> +#include <stdlib.h> +#include <stdint.h> + +static void inline reg_update_or(uint32_t reg, uint32_t val) +{ + uint32_t reg_val=mmio_read(reg); + reg_val |= val; + mmio_write(reg, reg_val); +} + +/* Configure STEPCONFIG register with average of 16 */ +static void inline stepc_update_16(uint32_t reg, uint32_t val) +{ + mmio_write(reg,(val | AM335X_ADC_AVG16)); +} + +/* Configure STEPDELAY register */ +static void inline stepd_update(uint32_t reg) +{ + mmio_write(reg,(0x0F)<<24); +} + +static uint32_t inline get_val(uint32_t reg, uint32_t val) +{ + return (mmio_read(reg) & val); +} + +void rtems_adc_init(void) +{ + /* Enable the CM_WKUP_ADC_CLKCTRL with CM_WKUP_MODUELEMODE_ENABLE */ + reg_update_or(AM335X_CM_WKUP_ADC_CLKCTRL, AM335X_CM_WKUP_MODULEMODE_ENABLE); + + while(!(get_val(AM335X_CM_WKUP_ADC_CLKCTRL,AM335X_CM_WKUP_MODULEMODE_ENABLE))) + { + /* Here waiting period for intialization of adc clock module */ + } + + /* Make sure STEPCONFIG write protect is off */ + reg_update_or(AM335X_ADC_CTRL, AM335X_ADC_STEPCONFIG_WRITE_PROTECT_OFF); + + /* ADC_STEPCONFIG for each AIN pin */ + stepc_update_16(AM335X_ADC_STEPCONFIG1,0x00<<19); + stepd_update(AM335X_ADC_STEPDELAY1); + stepc_update_16(AM335X_ADC_STEPCONFIG2,0x01<<19); + stepd_update(AM335X_ADC_STEPDELAY1); + stepc_update_16(AM335X_ADC_STEPCONFIG3,0x02<<19); + stepd_update(AM335X_ADC_STEPDELAY1); + stepc_update_16(AM335X_ADC_STEPCONFIG4,0x03<<19); + stepd_update(AM335X_ADC_STEPDELAY1); + stepc_update_16(AM335X_ADC_STEPCONFIG5,0x04<<19); + stepd_update(AM335X_ADC_STEPDELAY1); + stepc_update_16(AM335X_ADC_STEPCONFIG6,0x05<<19); + stepd_update(AM335X_ADC_STEPDELAY1); + stepc_update_16(AM335X_ADC_STEPCONFIG7,0x06<<19); + stepd_update(AM335X_ADC_STEPDELAY1); + stepc_update_16(AM335X_ADC_STEPCONFIG8,0x07<<19); + stepd_update(AM335X_ADC_STEPDELAY1); + + /* ADC_CTRL is enabled */ + reg_update_or(AM335X_ADC_CTRL,0x01); +} + +int rtems_adc_read(unsigned int pin_number) +{ + + /* The clock module is not enabled */ + if(get_val(AM335X_CM_WKUP_ADC_CLKCTRL,AM335X_CM_WKUP_IDLEST_DISABLED)) + rtems_adc_init(); + + /* Enable the step sequencer for the given pin */ + reg_update_or(AM335X_ADC_STEPENABLE,(0x01<<(pin_number+1))); + + /* Return the value of data register FIFO0 */ + return (get_val(AM335X_ADC_FIFO0DATA,AM335X_ADC_FIFO_MASK)); +} \ No newline at end of file diff --git a/c/src/lib/libbsp/arm/beagle/include/beagleboneblack.h b/c/src/lib/libbsp/arm/beagle/include/beagleboneblack.h index 5630645..4e6b589 100644 --- a/c/src/lib/libbsp/arm/beagle/include/beagleboneblack.h +++ b/c/src/lib/libbsp/arm/beagle/include/beagleboneblack.h @@ -56,6 +56,16 @@ #define BBB_P9_41 20 /* GPIO0_20 */ #define BBB_P9_42 7 /* GPIO0_7 */ +/* ADC pins on the BeagleBone Black */ +#define BBB_P9_33 4 /* AIN_4 */ +#define BBB_P9_34 7 /* AIN_7 */ +#define BBB_P9_35 6 /* AIN_6 */ +#define BBB_P9_36 5 /* AIN_5 */ +#define BBB_P9_37 2 /* AIN_2 */ +#define BBB_P9_38 3 /* AIN_3 */ +#define BBB_P9_39 0 /* AIN_0 */ +#define BBB_P9_40 1 /* AIN_1 */ + /* BSP related specifications */ #define GPIO_PIN_COUNT 128 #define GPIO_PINS_PER_BANK 32 diff --git a/c/src/lib/libcpu/arm/shared/include/am335x.h b/c/src/lib/libcpu/arm/shared/include/am335x.h index ebaa703..faba28b 100644 --- a/c/src/lib/libcpu/arm/shared/include/am335x.h +++ b/c/src/lib/libcpu/arm/shared/include/am335x.h @@ -319,4 +319,42 @@ #define AM335X_GPIO_CLEARDATAOUT 0x190 /* GPIO Output Clear Register */ #define AM335X_GPIO_SETDATAOUT 0x194 - /* GPIO Output Set Register */ \ No newline at end of file + /* GPIO Output Set Register */ + + +/* ADC registers */ +#define AM335X_ADC (0x44E0D000) +#define AM335X_CM_WKUP (0x44E00400) +#define AM335X_CM_WKUP_ADC_CLKCTRL (AM335X_CM_WKUP+0xBC) +#define AM335X_CM_WKUP_MODULEMODE_ENABLE (0x02) +#define AM335X_CM_WKUP_IDLEST_DISABLED (0x03<<16) + +#define AM335X_ADC_CTRL (AM335X_ADC+0x40) +#define AM335X_ADC_STEPENABLE (AM335X_ADC+0x54) +#define AM335X_ADC_STEPCONFIG_WRITE_PROTECT_OFF (0x01<<2) + +#define AM335X_ADC_STEPCONFIG1 (AM335X_ADC+0x64) +#define AM335X_ADC_STEPDELAY1 (AM335X_ADC+0x68) +#define AM335X_ADC_STEPCONFIG2 (AM335X_ADC+0x6C) +#define AM335X_ADC_STEPDELAY2 (AM335X_ADC+0x70) +#define AM335X_ADC_STEPCONFIG3 (AM335X_ADC+0x74) +#define AM335X_ADC_STEPDELAY3 (AM335X_ADC+0x78) +#define AM335X_ADC_STEPCONFIG4 (AM335X_ADC+0x7C) +#define AM335X_ADC_STEPDELAY4 (AM335X_ADC+0x80) +#define AM335X_ADC_STEPCONFIG5 (AM335X_ADC+0x84) +#define AM335X_ADC_STEPDELAY5 (AM335X_ADC+0x88) +#define AM335X_ADC_STEPCONFIG6 (AM335X_ADC+0x8C) +#define AM335X_ADC_STEPDELAY6 (AM335X_ADC+0x90) +#define AM335X_ADC_STEPCONFIG7 (AM335X_ADC+0x94) +#define AM335X_ADC_STEPDELAY7 (AM335X_ADC+0x98) +#define AM335X_ADC_STEPCONFIG8 (AM335X_ADC+0x9C) +#define AM335X_ADC_STEPDELAY8 (AM335X_ADC+0xA0) + +#define AM335X_ADC_AVG0 (0x000) +#define AM335X_ADC_AVG2 (0x001) +#define AM335X_ADC_AVG4 (0x010) +#define AM335X_ADC_AVG8 (0x011) +#define AM335X_ADC_AVG16 (0x100) + +#define AM335X_ADC_FIFO0DATA (AM335X_ADC+0x100) +#define AM335X_ADC_FIFO_MASK (0xFFF) diff --git a/cpukit/include/rtems/gpio.h b/cpukit/include/rtems/gpio.h index 2b9ebf7..58f1f61 100644 --- a/cpukit/include/rtems/gpio.h +++ b/cpukit/include/rtems/gpio.h @@ -61,5 +61,12 @@ extern int rtems_gpio_digital_clear(gpio_pin_handle *); * @brief currently configured pin is released and made UNCONFIGURED. */ extern int rtems_gpio_release_pin(gpio_pin_handle *); - +/** + * @brief ADC intialization. + */ +extern void rtems_adc_init(); +/** + * @brief Reads the ADC value for input from pin. + */ +extern int rtems_adc_read(unsigned int); #endif /* _RTEMS_GPIO_H */ \ No newline at end of file
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