438 lines
12 KiB
C
438 lines
12 KiB
C
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/*
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* PCA9552 I2C LED blinker
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*
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* https://www.nxp.com/docs/en/application-note/AN264.pdf
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*
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* Copyright (c) 2017-2018, IBM Corporation.
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* Copyright (c) 2020 Philippe Mathieu-Daudé
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*
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* This work is licensed under the terms of the GNU GPL, version 2 or
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* later. See the COPYING file in the top-level directory.
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*/
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#include "qemu/osdep.h"
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#include "qemu/log.h"
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#include "qemu/module.h"
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#include "qemu/bitops.h"
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#include "hw/qdev-properties.h"
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#include "hw/misc/pca9552.h"
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#include "hw/misc/pca9552_regs.h"
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#include "hw/irq.h"
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#include "migration/vmstate.h"
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#include "qapi/error.h"
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#include "qapi/visitor.h"
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#include "trace.h"
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typedef struct PCA955xClass {
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/*< private >*/
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I2CSlaveClass parent_class;
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/*< public >*/
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uint8_t pin_count;
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uint8_t max_reg;
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} PCA955xClass;
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#define PCA955X_CLASS(klass) \
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OBJECT_CLASS_CHECK(PCA955xClass, (klass), TYPE_PCA955X)
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#define PCA955X_GET_CLASS(obj) \
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OBJECT_GET_CLASS(PCA955xClass, (obj), TYPE_PCA955X)
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#define PCA9552_LED_ON 0x0
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#define PCA9552_LED_OFF 0x1
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#define PCA9552_LED_PWM0 0x2
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#define PCA9552_LED_PWM1 0x3
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static const char *led_state[] = {"on", "off", "pwm0", "pwm1"};
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static uint8_t pca955x_pin_get_config(PCA955xState *s, int pin)
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{
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uint8_t reg = PCA9552_LS0 + (pin / 4);
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uint8_t shift = (pin % 4) << 1;
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return extract32(s->regs[reg], shift, 2);
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}
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/* Return INPUT status (bit #N belongs to GPIO #N) */
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static uint16_t pca955x_pins_get_status(PCA955xState *s)
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{
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return (s->regs[PCA9552_INPUT1] << 8) | s->regs[PCA9552_INPUT0];
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}
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static void pca955x_display_pins_status(PCA955xState *s,
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uint16_t previous_pins_status)
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{
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PCA955xClass *k = PCA955X_GET_CLASS(s);
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uint16_t pins_status, pins_changed;
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int i;
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pins_status = pca955x_pins_get_status(s);
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pins_changed = previous_pins_status ^ pins_status;
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if (!pins_changed) {
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return;
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}
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if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_STATUS)) {
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char *buf = g_newa(char, k->pin_count + 1);
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for (i = 0; i < k->pin_count; i++) {
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if (extract32(pins_status, i, 1)) {
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buf[i] = '*';
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} else {
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buf[i] = '.';
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}
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}
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buf[i] = '\0';
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trace_pca955x_gpio_status(s->description, buf);
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}
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if (trace_event_get_state_backends(TRACE_PCA955X_GPIO_CHANGE)) {
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for (i = 0; i < k->pin_count; i++) {
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if (extract32(pins_changed, i, 1)) {
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unsigned new_state = extract32(pins_status, i, 1);
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/*
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* We display the state using the PCA logic ("active-high").
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* This is not the state of the LED, which signal might be
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* wired "active-low" on the board.
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*/
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trace_pca955x_gpio_change(s->description, i,
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!new_state, new_state);
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}
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}
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}
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}
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static void pca955x_update_pin_input(PCA955xState *s)
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{
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PCA955xClass *k = PCA955X_GET_CLASS(s);
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int i;
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for (i = 0; i < k->pin_count; i++) {
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uint8_t input_reg = PCA9552_INPUT0 + (i / 8);
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uint8_t input_shift = (i % 8);
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uint8_t config = pca955x_pin_get_config(s, i);
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switch (config) {
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case PCA9552_LED_ON:
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qemu_set_irq(s->gpio[i], 1);
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s->regs[input_reg] |= 1 << input_shift;
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break;
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case PCA9552_LED_OFF:
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qemu_set_irq(s->gpio[i], 0);
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s->regs[input_reg] &= ~(1 << input_shift);
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break;
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case PCA9552_LED_PWM0:
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case PCA9552_LED_PWM1:
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/* TODO */
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default:
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break;
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}
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}
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}
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static uint8_t pca955x_read(PCA955xState *s, uint8_t reg)
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{
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switch (reg) {
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case PCA9552_INPUT0:
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case PCA9552_INPUT1:
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case PCA9552_PSC0:
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case PCA9552_PWM0:
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case PCA9552_PSC1:
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case PCA9552_PWM1:
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case PCA9552_LS0:
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case PCA9552_LS1:
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case PCA9552_LS2:
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case PCA9552_LS3:
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return s->regs[reg];
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default:
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qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected read to register %d\n",
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__func__, reg);
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return 0xFF;
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}
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}
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static void pca955x_write(PCA955xState *s, uint8_t reg, uint8_t data)
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{
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uint16_t pins_status;
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switch (reg) {
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case PCA9552_PSC0:
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case PCA9552_PWM0:
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case PCA9552_PSC1:
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case PCA9552_PWM1:
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s->regs[reg] = data;
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break;
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case PCA9552_LS0:
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case PCA9552_LS1:
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case PCA9552_LS2:
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case PCA9552_LS3:
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pins_status = pca955x_pins_get_status(s);
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s->regs[reg] = data;
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pca955x_update_pin_input(s);
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pca955x_display_pins_status(s, pins_status);
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break;
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case PCA9552_INPUT0:
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case PCA9552_INPUT1:
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default:
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qemu_log_mask(LOG_GUEST_ERROR, "%s: unexpected write to register %d\n",
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__func__, reg);
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}
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}
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/*
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* When Auto-Increment is on, the register address is incremented
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* after each byte is sent to or received by the device. The index
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* rollovers to 0 when the maximum register address is reached.
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*/
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static void pca955x_autoinc(PCA955xState *s)
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{
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PCA955xClass *k = PCA955X_GET_CLASS(s);
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if (s->pointer != 0xFF && s->pointer & PCA9552_AUTOINC) {
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uint8_t reg = s->pointer & 0xf;
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reg = (reg + 1) % (k->max_reg + 1);
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s->pointer = reg | PCA9552_AUTOINC;
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}
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}
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static uint8_t pca955x_recv(I2CSlave *i2c)
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{
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PCA955xState *s = PCA955X(i2c);
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uint8_t ret;
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ret = pca955x_read(s, s->pointer & 0xf);
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/*
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* From the Specs:
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*
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* Important Note: When a Read sequence is initiated and the
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* AI bit is set to Logic Level 1, the Read Sequence MUST
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* start by a register different from 0.
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*
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* I don't know what should be done in this case, so throw an
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* error.
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*/
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if (s->pointer == PCA9552_AUTOINC) {
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qemu_log_mask(LOG_GUEST_ERROR,
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"%s: Autoincrement read starting with register 0\n",
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__func__);
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}
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pca955x_autoinc(s);
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return ret;
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}
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static int pca955x_send(I2CSlave *i2c, uint8_t data)
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{
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PCA955xState *s = PCA955X(i2c);
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/* First byte sent by is the register address */
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if (s->len == 0) {
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s->pointer = data;
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s->len++;
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} else {
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pca955x_write(s, s->pointer & 0xf, data);
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pca955x_autoinc(s);
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}
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return 0;
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}
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static int pca955x_event(I2CSlave *i2c, enum i2c_event event)
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{
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PCA955xState *s = PCA955X(i2c);
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s->len = 0;
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return 0;
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}
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static void pca955x_get_led(Object *obj, Visitor *v, const char *name,
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void *opaque, Error **errp)
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{
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PCA955xClass *k = PCA955X_GET_CLASS(obj);
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PCA955xState *s = PCA955X(obj);
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int led, rc, reg;
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uint8_t state;
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rc = sscanf(name, "led%2d", &led);
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if (rc != 1) {
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error_setg(errp, "%s: error reading %s", __func__, name);
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return;
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}
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if (led < 0 || led > k->pin_count) {
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error_setg(errp, "%s invalid led %s", __func__, name);
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return;
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}
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/*
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* Get the LSx register as the qom interface should expose the device
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* state, not the modeled 'input line' behaviour which would come from
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* reading the INPUTx reg
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*/
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reg = PCA9552_LS0 + led / 4;
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state = (pca955x_read(s, reg) >> (led % 8)) & 0x3;
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visit_type_str(v, name, (char **)&led_state[state], errp);
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}
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/*
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* Return an LED selector register value based on an existing one, with
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* the appropriate 2-bit state value set for the given LED number (0-3).
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*/
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static inline uint8_t pca955x_ledsel(uint8_t oldval, int led_num, int state)
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{
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return (oldval & (~(0x3 << (led_num << 1)))) |
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((state & 0x3) << (led_num << 1));
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}
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static void pca955x_set_led(Object *obj, Visitor *v, const char *name,
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void *opaque, Error **errp)
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{
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PCA955xClass *k = PCA955X_GET_CLASS(obj);
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PCA955xState *s = PCA955X(obj);
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int led, rc, reg, val;
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uint8_t state;
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char *state_str;
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if (!visit_type_str(v, name, &state_str, errp)) {
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return;
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}
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rc = sscanf(name, "led%2d", &led);
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if (rc != 1) {
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error_setg(errp, "%s: error reading %s", __func__, name);
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return;
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}
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if (led < 0 || led > k->pin_count) {
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error_setg(errp, "%s invalid led %s", __func__, name);
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return;
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}
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for (state = 0; state < ARRAY_SIZE(led_state); state++) {
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if (!strcmp(state_str, led_state[state])) {
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break;
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}
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}
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if (state >= ARRAY_SIZE(led_state)) {
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error_setg(errp, "%s invalid led state %s", __func__, state_str);
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return;
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}
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reg = PCA9552_LS0 + led / 4;
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val = pca955x_read(s, reg);
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val = pca955x_ledsel(val, led % 4, state);
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pca955x_write(s, reg, val);
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}
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static const VMStateDescription pca9552_vmstate = {
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.name = "PCA9552",
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.version_id = 0,
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.minimum_version_id = 0,
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.fields = (VMStateField[]) {
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VMSTATE_UINT8(len, PCA955xState),
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VMSTATE_UINT8(pointer, PCA955xState),
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VMSTATE_UINT8_ARRAY(regs, PCA955xState, PCA955X_NR_REGS),
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VMSTATE_I2C_SLAVE(i2c, PCA955xState),
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VMSTATE_END_OF_LIST()
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}
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};
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static void pca9552_reset(DeviceState *dev)
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{
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PCA955xState *s = PCA955X(dev);
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s->regs[PCA9552_PSC0] = 0xFF;
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s->regs[PCA9552_PWM0] = 0x80;
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s->regs[PCA9552_PSC1] = 0xFF;
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s->regs[PCA9552_PWM1] = 0x80;
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s->regs[PCA9552_LS0] = 0x55; /* all OFF */
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s->regs[PCA9552_LS1] = 0x55;
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s->regs[PCA9552_LS2] = 0x55;
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s->regs[PCA9552_LS3] = 0x55;
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pca955x_update_pin_input(s);
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s->pointer = 0xFF;
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s->len = 0;
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}
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static void pca955x_initfn(Object *obj)
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{
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PCA955xClass *k = PCA955X_GET_CLASS(obj);
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int led;
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assert(k->pin_count <= PCA955X_PIN_COUNT_MAX);
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|
|
for (led = 0; led < k->pin_count; led++) {
|
||
|
|
char *name;
|
||
|
|
|
||
|
|
name = g_strdup_printf("led%d", led);
|
||
|
|
object_property_add(obj, name, "bool", pca955x_get_led, pca955x_set_led,
|
||
|
|
NULL, NULL);
|
||
|
|
g_free(name);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
static void pca955x_realize(DeviceState *dev, Error **errp)
|
||
|
|
{
|
||
|
|
PCA955xClass *k = PCA955X_GET_CLASS(dev);
|
||
|
|
PCA955xState *s = PCA955X(dev);
|
||
|
|
|
||
|
|
if (!s->description) {
|
||
|
|
s->description = g_strdup("pca-unspecified");
|
||
|
|
}
|
||
|
|
|
||
|
|
qdev_init_gpio_out(dev, s->gpio, k->pin_count);
|
||
|
|
}
|
||
|
|
|
||
|
|
static Property pca955x_properties[] = {
|
||
|
|
DEFINE_PROP_STRING("description", PCA955xState, description),
|
||
|
|
DEFINE_PROP_END_OF_LIST(),
|
||
|
|
};
|
||
|
|
|
||
|
|
static void pca955x_class_init(ObjectClass *klass, void *data)
|
||
|
|
{
|
||
|
|
DeviceClass *dc = DEVICE_CLASS(klass);
|
||
|
|
I2CSlaveClass *k = I2C_SLAVE_CLASS(klass);
|
||
|
|
|
||
|
|
k->event = pca955x_event;
|
||
|
|
k->recv = pca955x_recv;
|
||
|
|
k->send = pca955x_send;
|
||
|
|
dc->realize = pca955x_realize;
|
||
|
|
device_class_set_props(dc, pca955x_properties);
|
||
|
|
}
|
||
|
|
|
||
|
|
static const TypeInfo pca955x_info = {
|
||
|
|
.name = TYPE_PCA955X,
|
||
|
|
.parent = TYPE_I2C_SLAVE,
|
||
|
|
.instance_init = pca955x_initfn,
|
||
|
|
.instance_size = sizeof(PCA955xState),
|
||
|
|
.class_init = pca955x_class_init,
|
||
|
|
.class_size = sizeof(PCA955xClass),
|
||
|
|
.abstract = true,
|
||
|
|
};
|
||
|
|
|
||
|
|
static void pca9552_class_init(ObjectClass *oc, void *data)
|
||
|
|
{
|
||
|
|
DeviceClass *dc = DEVICE_CLASS(oc);
|
||
|
|
PCA955xClass *pc = PCA955X_CLASS(oc);
|
||
|
|
|
||
|
|
dc->reset = pca9552_reset;
|
||
|
|
dc->vmsd = &pca9552_vmstate;
|
||
|
|
pc->max_reg = PCA9552_LS3;
|
||
|
|
pc->pin_count = 16;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const TypeInfo pca9552_info = {
|
||
|
|
.name = TYPE_PCA9552,
|
||
|
|
.parent = TYPE_PCA955X,
|
||
|
|
.class_init = pca9552_class_init,
|
||
|
|
};
|
||
|
|
|
||
|
|
static void pca955x_register_types(void)
|
||
|
|
{
|
||
|
|
type_register_static(&pca955x_info);
|
||
|
|
type_register_static(&pca9552_info);
|
||
|
|
}
|
||
|
|
|
||
|
|
type_init(pca955x_register_types)
|