[PATCH RTEMS] bsps/beagle: Refactored i2c driver
Niteesh G. S.
niteesh.gs at gmail.com
Mon Mar 22 17:50:39 UTC 2021
Hii,
I have tested this patch by reading out the values from the EEPROM in i2c-0
and also reading out data from a sensor connected to i2c-1. For reading
data from the sensor, I used RTEMS Shell with i2cget and i2cset. All this
was
done on a PocketBeagle.
Thanks,
Niteesh.
On Mon, Mar 22, 2021 at 11:18 PM G S Niteesh Babu <niteesh.gs at gmail.com>
wrote:
> Refactored the i2c driver to parse register values from the device
> tree rather than hardcoding them. But still the clocks have to
> initialized manually.
> ---
> bsps/arm/beagle/i2c/bbb-i2c.c | 100 ++++++++++++++++--------------
> bsps/arm/beagle/include/bsp.h | 4 ++
> bsps/arm/beagle/include/bsp/i2c.h | 32 +---------
> bsps/arm/beagle/start/bspstart.c | 53 +++++++++++-----
> 4 files changed, 96 insertions(+), 93 deletions(-)
>
> diff --git a/bsps/arm/beagle/i2c/bbb-i2c.c b/bsps/arm/beagle/i2c/bbb-i2c.c
> index b2a7cf814d..c315b6fc3b 100644
> --- a/bsps/arm/beagle/i2c/bbb-i2c.c
> +++ b/bsps/arm/beagle/i2c/bbb-i2c.c
> @@ -25,6 +25,7 @@
> #include <bsp/bbb-gpio.h>
> #include <rtems/score/assert.h>
> #include <dev/i2c/i2c.h>
> +#include <ofw/ofw.h>
>
> typedef struct bbb_i2c_bus {
> i2c_bus base;
> @@ -34,12 +35,6 @@ typedef struct bbb_i2c_bus {
> volatile uint32_t *i2c_clkctrl;
> volatile uint32_t *clkstctrl;
> } clkregs;
> - struct {
> - volatile uint32_t *conf_sda;
> - uint32_t mmode_sda;
> - volatile uint32_t *conf_scl;
> - uint32_t mmode_scl;
> - } pinregs;
> rtems_id task_id;
> rtems_vector_number irq;
> i2c_msg *buffer;
> @@ -56,19 +51,29 @@ typedef struct bbb_i2c_bus {
> #else
> #define debug_print(fmt, args...)
> #endif
> +/*
> + * Here we assume the number of i2c nodes
> + * will be less than 100.
> + */
> +#define PATH_LEN strlen("/dev/i2c-xx")
>
> static int am335x_i2c_fill_registers(
> bbb_i2c_bus *bus,
> - uintptr_t register_base
> + phandle_t node
> )
> {
> - /* FIXME: The pin handling should be replaced by a proper pin handling
> during
> - * initialization. This one is heavily board specific. */
> -#if ! IS_AM335X
> - printk ("The I2C driver currently only works on Beagle Bone. Please add
> your pin configs.");
> - return EINVAL;
> -#endif
> - bus->regs = (volatile bbb_i2c_regs *) register_base;
> + ssize_t rv;
> + rtems_ofw_memory_area reg;
> +
> + rv = rtems_ofw_get_reg(node, ®, sizeof(reg));
> + if (rv <= 0)
> + return EINVAL;
> +
> + bus->regs = (volatile bbb_i2c_regs *)reg.start;
> +
> + /*
> + * FIXME: Implement a clock driver to parse and setup clocks
> + */
> switch ((intptr_t) bus->regs) {
> case AM335X_I2C0_BASE:
> bus->clkregs.ctrl_clkctrl = ®(AM335X_SOC_CM_WKUP_REGS +
> @@ -77,10 +82,6 @@ static int am335x_i2c_fill_registers(
> AM335X_CM_WKUP_I2C0_CLKCTRL);
> bus->clkregs.clkstctrl = ®(AM335X_SOC_CM_WKUP_REGS +
> AM335X_CM_WKUP_CLKSTCTRL);
> - bus->pinregs.conf_sda = ®(AM335X_PADCONF_BASE +
> AM335X_CONF_I2C0_SDA);
> - bus->pinregs.mmode_sda = 0;
> - bus->pinregs.conf_scl = ®(AM335X_PADCONF_BASE +
> AM335X_CONF_I2C0_SCL);
> - bus->pinregs.mmode_scl = 0;
> break;
> case AM335X_I2C1_BASE:
> bus->clkregs.ctrl_clkctrl = ®(AM335X_SOC_CM_WKUP_REGS +
> @@ -88,10 +89,6 @@ static int am335x_i2c_fill_registers(
> bus->clkregs.i2c_clkctrl = ®(AM335X_CM_PER_ADDR +
> AM335X_CM_PER_I2C1_CLKCTRL);
> bus->clkregs.clkstctrl = NULL;
> - bus->pinregs.conf_sda = ®(AM335X_PADCONF_BASE +
> AM335X_CONF_SPI0_D1);
> - bus->pinregs.mmode_sda = 2;
> - bus->pinregs.conf_scl = ®(AM335X_PADCONF_BASE +
> AM335X_CONF_SPI0_CS0);
> - bus->pinregs.mmode_scl = 2;
> break;
> case AM335X_I2C2_BASE:
> bus->clkregs.ctrl_clkctrl = ®(AM335X_SOC_CM_WKUP_REGS +
> @@ -99,24 +96,12 @@ static int am335x_i2c_fill_registers(
> bus->clkregs.i2c_clkctrl = ®(AM335X_CM_PER_ADDR +
> AM335X_CM_PER_I2C2_CLKCTRL);
> bus->clkregs.clkstctrl = NULL;
> - bus->pinregs.conf_sda = ®(AM335X_PADCONF_BASE +
> AM335X_CONF_UART1_CTSN);
> - bus->pinregs.mmode_sda = 3;
> - bus->pinregs.conf_scl = ®(AM335X_PADCONF_BASE +
> AM335X_CONF_UART1_RTSN);
> - bus->pinregs.mmode_scl = 3;
> break;
> default:
> return EINVAL;
> }
> - return 0;
> -}
>
> -static void am335x_i2c_pinmux( bbb_i2c_bus *bus )
> -{
> - *bus->pinregs.conf_sda =
> - ( BBB_RXACTIVE | BBB_SLEWCTRL | bus->pinregs.mmode_sda);
> -
> - *bus->pinregs.conf_scl =
> - ( BBB_RXACTIVE | BBB_SLEWCTRL | bus->pinregs.mmode_scl);
> + return 0;
> }
>
> static void am335x_i2c_module_clk_enable( bbb_i2c_bus *bus )
> @@ -453,18 +438,16 @@ static void am335x_i2c_destroy( i2c_bus *base )
> i2c_bus_destroy_and_free( &bus->base );
> }
>
> -int am335x_i2c_bus_register(
> - const char *bus_path,
> - uintptr_t register_base,
> - uint32_t input_clock,
> - rtems_vector_number irq
> +static int am335x_i2c_bus_register(
> + phandle_t node
> )
> {
> - bbb_i2c_bus *bus;
> - rtems_status_code sc;
> - int err;
> -
> - (void) input_clock; /* FIXME: Unused. Left for compatibility. */
> + bbb_i2c_bus *bus;
> + rtems_status_code sc;
> + rtems_vector_number irq;
> + int err;
> + int unit;
> + char bus_path[PATH_LEN];
>
> bus = (bbb_i2c_bus *) i2c_bus_alloc_and_init( sizeof( *bus ) );
>
> @@ -472,15 +455,24 @@ int am335x_i2c_bus_register(
> return -1;
> }
>
> + unit = beagle_get_node_unit(node);
> +
> + snprintf(bus_path, PATH_LEN, "/dev/i2c-%d", unit);
> +
> + err = rtems_ofw_get_interrupts(node, &irq, sizeof(irq));
> + if (err < 1) {
> + ( *bus->base.destroy )( &bus->base );
> + rtems_set_errno_and_return_minus_one( err );
> + }
> bus->irq = irq;
>
> - err = am335x_i2c_fill_registers(bus, register_base);
> + err = am335x_i2c_fill_registers(bus, node);
> if (err != 0) {
> ( *bus->base.destroy )( &bus->base );
> rtems_set_errno_and_return_minus_one( err );
> }
> - am335x_i2c_module_clk_enable(bus);
> - am335x_i2c_pinmux( bus );
> +
> + am335x_i2c_module_clk_enable( bus );
> err = am335x_i2c_reset( bus );
> if (err != 0) {
> ( *bus->base.destroy )( &bus->base );
> @@ -506,3 +498,15 @@ int am335x_i2c_bus_register(
>
> return i2c_bus_register( &bus->base, bus_path );
> }
> +
> +void beagle_i2c_init(phandle_t node)
> +{
> + int rv;
> +
> + if (!rtems_ofw_is_node_compatible(node, "ti,omap4-i2c"))
> + return ;
> +
> + rv = am335x_i2c_bus_register(node);
> + if (rv != 0)
> + printk("i2c: Could not register device (%d)\n", rv);
> +}
> diff --git a/bsps/arm/beagle/include/bsp.h b/bsps/arm/beagle/include/bsp.h
> index cb415fda89..80a9cc291d 100644
> --- a/bsps/arm/beagle/include/bsp.h
> +++ b/bsps/arm/beagle/include/bsp.h
> @@ -49,6 +49,8 @@
> #include <libcpu/omap3.h>
> #include <libcpu/am335x.h>
>
> +#include <ofw/ofw.h>
> +
> #define BSP_FEATURE_IRQ_EXTENSION
>
> /* UART base clock frequency */
> @@ -68,6 +70,8 @@
>
> #define udelay(u) rtems_task_wake_after(1 +
> ((u)/rtems_configuration_get_microseconds_per_tick()))
>
> +int beagle_get_node_unit(phandle_t node);
> +
> /* Write a uint32_t value to a memory address. */
> static inline void
> write32(uint32_t address, uint32_t value)
> diff --git a/bsps/arm/beagle/include/bsp/i2c.h
> b/bsps/arm/beagle/include/bsp/i2c.h
> index 60f71194bf..d80b376fa0 100644
> --- a/bsps/arm/beagle/include/bsp/i2c.h
> +++ b/bsps/arm/beagle/include/bsp/i2c.h
> @@ -26,6 +26,7 @@
> #include <rtems.h>
> #include <bsp.h>
> #include <dev/i2c/i2c.h>
> +#include <ofw/ofw.h>
>
> #ifdef __cplusplus
> extern "C" {
> @@ -38,10 +39,6 @@ extern "C" {
> #define BBB_I2C_1_BUS_PATH "/dev/i2c-1"
> #define BBB_I2C_2_BUS_PATH "/dev/i2c-2"
>
> -#define BBB_I2C0_IRQ 70
> -#define BBB_I2C1_IRQ 71
> -#define BBB_I2C2_IRQ 30
> -
> typedef enum {
> I2C0,
> I2C1,
> @@ -87,32 +84,7 @@ typedef struct i2c_regs {
> uint32_t BBB_I2C_SBLOCK;
> } bbb_i2c_regs;
>
> -int am335x_i2c_bus_register(
> - const char *bus_path,
> - uintptr_t register_base,
> - uint32_t input_clock, /* FIXME: Unused. Left for
> compatibility. */
> - rtems_vector_number irq
> -);
> -
> -static inline int bbb_register_i2c_1( void )
> -{
> - return am335x_i2c_bus_register(
> - BBB_I2C_1_BUS_PATH,
> - AM335X_I2C1_BASE,
> - I2C_BUS_CLOCK_DEFAULT,
> - BBB_I2C1_IRQ
> - );
> -}
> -
> -static inline int bbb_register_i2c_2( void )
> -{
> - return am335x_i2c_bus_register(
> - BBB_I2C_2_BUS_PATH,
> - AM335X_I2C2_BASE,
> - I2C_BUS_CLOCK_DEFAULT,
> - BBB_I2C2_IRQ
> - );
> -}
> +void beagle_i2c_init( phandle_t node );
>
> #ifdef __cplusplus
> }
> diff --git a/bsps/arm/beagle/start/bspstart.c
> b/bsps/arm/beagle/start/bspstart.c
> index a0736294c9..d45eec9e92 100644
> --- a/bsps/arm/beagle/start/bspstart.c
> +++ b/bsps/arm/beagle/start/bspstart.c
> @@ -22,9 +22,15 @@
> #include "bsp-soc-detect.h"
> #include <arm/ti/ti_pinmux.h>
> #include <ofw/ofw.h>
> +#include <bsp/i2c.h>
> +#include <string.h>
> +#include <stdlib.h>
> +#include <ctype.h>
>
> #include "bspdebug.h"
>
> +#define MIN(l,r) ((l) < (r) ? (l) : (r))
> +
> void bsp_start(void)
> {
> const char *type;
> @@ -70,6 +76,7 @@ static void traverse_fdt_nodes( phandle_t node )
> * Put all driver initialization functions here
> */
> beagle_pinmux_init(node);
> + beagle_i2c_init(node);
> }
> }
>
> @@ -80,24 +87,40 @@ static void bbb_drivers_initialize(void)
> traverse_fdt_nodes(node);
> }
>
> -static void bbb_i2c_0_initialize(void)
> +int beagle_get_node_unit(phandle_t node)
> {
> - int err;
> -
> - err = am335x_i2c_bus_register(BBB_I2C_0_BUS_PATH,
> - AM335X_I2C0_BASE,
> - I2C_BUS_CLOCK_DEFAULT,
> - BBB_I2C0_IRQ);
> - if (err != 0) {
> - printk("rtems i2c-0: Device could not be registered (%d)", err);
> + char name[30];
> + char prop[30];
> + char prop_val[30];
> + static int unit;
> + phandle_t aliases;
> + int rv;
> + int i;
> +
> + rv = rtems_ofw_get_prop(node, "name", name, sizeof(name));
> + if (rv <= 0)
> + return unit++;
> +
> + aliases = rtems_ofw_find_device("/aliases");
> +
> + rv = rtems_ofw_next_prop(aliases, NULL, &prop[0], sizeof(prop));
> +
> + while (rv > 0) {
> + rv = rtems_ofw_get_prop(aliases, prop, prop_val, sizeof(prop_val));
> +
> + if (strstr(prop_val, name) != NULL) {
> + for (i = strlen(prop) - 1; i >= 0; i--) {
> + if (!isdigit(prop[i]))
> + break;
> + }
> +
> + return strtol(&prop[i + 1], NULL, 10);
> + }
> + rv = rtems_ofw_next_prop(aliases, prop, prop, sizeof(prop));
> }
> -}
>
> -RTEMS_SYSINIT_ITEM(
> - bbb_i2c_0_initialize,
> - RTEMS_SYSINIT_LAST,
> - RTEMS_SYSINIT_ORDER_LAST_BUT_5
> -);
> + return unit++;
> +}
>
> RTEMS_SYSINIT_ITEM(
> bbb_drivers_initialize,
> --
> 2.17.1
>
>
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