1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #include <acpi/acpi_device.h>
4 #include <acpi/acpigen.h>
5 #include <commonlib/bsd/bcd.h>
6 #include <console/console.h>
7 #include <device/device.h>
8 #include <device/i2c.h>
9 #include <device/i2c_bus.h>
10 #include <timer.h>
11 #include <version.h>
12 #include "chip.h"
13 #include "rx6110sa.h"
14
15 /* Function to write a register in the RTC with the given value. */
rx6110sa_write(struct device * dev,uint8_t reg,uint8_t val)16 static void rx6110sa_write(struct device *dev, uint8_t reg, uint8_t val)
17 {
18 i2c_dev_writeb_at(dev, reg, val);
19 }
20
21 /* Function to read a register in the RTC. */
rx6110sa_read(struct device * dev,uint8_t reg)22 static uint8_t rx6110sa_read(struct device *dev, uint8_t reg)
23 {
24 return (uint8_t)i2c_dev_readb_at(dev, reg);
25 }
26
27 /* Set RTC date from coreboot build date. */
rx6110sa_set_build_date(struct device * dev)28 static void rx6110sa_set_build_date(struct device *dev)
29 {
30 rx6110sa_write(dev, YEAR_REG, coreboot_build_date.year);
31 rx6110sa_write(dev, MONTH_REG, coreboot_build_date.month);
32 rx6110sa_write(dev, DAY_REG, coreboot_build_date.day);
33 rx6110sa_write(dev, WEEK_REG, (1 << coreboot_build_date.weekday));
34 }
35
36 /* Set RTC date from user defined date (available in e.g. device tree). */
rx6110sa_set_user_date(struct device * dev)37 static void rx6110sa_set_user_date(struct device *dev)
38 {
39 struct drivers_i2c_rx6110sa_config *config = dev->chip_info;
40
41 rx6110sa_write(dev, YEAR_REG, bin2bcd(config->user_year));
42 rx6110sa_write(dev, MONTH_REG, bin2bcd(config->user_month));
43 rx6110sa_write(dev, DAY_REG, bin2bcd(config->user_day));
44 rx6110sa_write(dev, WEEK_REG, (1 << config->user_weekday));
45 }
46
rx6110sa_final(struct device * dev)47 static void rx6110sa_final(struct device *dev)
48 {
49 uint8_t hour, minute, second, year, month, day;
50
51 /* Read back current RTC date and time and print it to the console. */
52 hour = rx6110sa_read(dev, HOUR_REG);
53 minute = rx6110sa_read(dev, MINUTE_REG);
54 second = rx6110sa_read(dev, SECOND_REG);
55 year = rx6110sa_read(dev, YEAR_REG);
56 month = rx6110sa_read(dev, MONTH_REG);
57 day = rx6110sa_read(dev, DAY_REG);
58
59 printk(BIOS_INFO, "%s: Current date %02d.%02d.%02d %02d:%02d:%02d\n",
60 dev->chip_ops->name, bcd2bin(month), bcd2bin(day),
61 bcd2bin(year), bcd2bin(hour), bcd2bin(minute), bcd2bin(second));
62 }
63
rx6110sa_init(struct device * dev)64 static void rx6110sa_init(struct device *dev)
65 {
66 struct drivers_i2c_rx6110sa_config *config = dev->chip_info;
67 uint8_t reg, flags;
68 struct stopwatch sw;
69
70 /* Do a dummy read first as requested in the datasheet. */
71 rx6110sa_read(dev, SECOND_REG);
72 /* Check power loss status by reading the VLF-bit. */
73 flags = rx6110sa_read(dev, FLAG_REGISTER);
74 if (flags & VLF_BIT) {
75 /*
76 * Voltage low detected, perform RX6110 SA reset sequence as
77 * requested in the datasheet. The meaning of the registers 0x60
78 * and above is not documented in the datasheet, they have to be
79 * used as requested according to Epson.
80 */
81 rx6110sa_write(dev, BATTERY_BACKUP_REG, 0x00);
82 rx6110sa_write(dev, CTRL_REG, 0x00);
83 rx6110sa_write(dev, CTRL_REG, TEST_BIT);
84 rx6110sa_write(dev, 0x60, 0xd3);
85 rx6110sa_write(dev, 0x66, 0x03);
86 rx6110sa_write(dev, 0x6b, 0x02);
87 rx6110sa_write(dev, 0x6b, 0x01);
88 /* According to the datasheet one have to wait for at least 2 ms
89 * before the VLF bit can be cleared in the flag register after
90 * this reset sequence. As the other registers are still
91 * accessible use the stopwatch to parallel the flow.
92 */
93 stopwatch_init_msecs_expire(&sw, AFTER_RESET_DELAY_MS);
94 }
95 /*
96 * Set up important registers even if there was no power loss to make
97 * sure that the right mode is used as it directly influences the
98 * backup current consumption and therefore the backup time. These
99 * settings do not change current date and time and the RTC will not
100 * be stopped while the registers are set up.
101 */
102 reg = (config->pmon_sampling & PMON_SAMPL_MASK) |
103 (!!config->bks_off << 2) | (!!config->bks_on << 3) |
104 (!!config->iocut_en << 4);
105 rx6110sa_write(dev, BATTERY_BACKUP_REG, reg);
106
107 /* Clear timer enable bit and set frequency of clock output. */
108 reg = rx6110sa_read(dev, EXTENSION_REG);
109 reg &= ~(FSEL_MASK);
110 reg |= ((config->cof_selection << 6) & FSEL_MASK);
111 if (config->timer_preset) {
112 /* Timer needs to be in stop mode prior to programming it. */
113 if (reg & TE_BIT) {
114 reg &= ~TE_BIT;
115 rx6110sa_write(dev, EXTENSION_REG, reg);
116 }
117 /* Program the timer preset value. */
118 rx6110sa_write(dev, TMR_COUNTER_0_REG,
119 config->timer_preset & 0xff);
120 rx6110sa_write(dev, TMR_COUNTER_1_REG,
121 (config->timer_preset >> 8) & 0xff);
122 /* Set Timer Enable bit and the timer clock value. */
123 reg &= ~TSEL_MASK;
124 reg |= ((!!config->timer_en << 4) |
125 (config->timer_clk & TSEL_MASK));
126 }
127 rx6110sa_write(dev, EXTENSION_REG, reg);
128 rx6110sa_write(dev, CTRL_REG, 0x00);
129 rx6110sa_write(dev, DIGITAL_REG, 0x00);
130 rx6110sa_write(dev, RESERVED_BIT_REG, RTC_INIT_VALUE);
131 reg = (!!config->enable_1hz_out << 4) |
132 (!!config->irq_output_pin << 2) |
133 (config->fout_output_pin & FOUT_OUTPUT_PIN_MASK);
134 rx6110sa_write(dev, IRQ_CONTROL_REG, reg);
135 /* If there was no power loss event no further steps are needed. */
136 if (!(flags & VLF_BIT))
137 return;
138 /* There was a power loss event, clear voltage low detect bit.
139 * Take the needed delay after a reset sequence into account before the
140 * VLF-bit can be cleared.
141 */
142 stopwatch_wait_until_expired(&sw);
143 flags &= ~VLF_BIT;
144 rx6110sa_write(dev, FLAG_REGISTER, flags);
145
146 /* Before setting the clock stop oscillator. */
147 rx6110sa_write(dev, CTRL_REG, STOP_BIT);
148
149 if (config->set_user_date) {
150 /* Set user date defined in device tree. */
151 printk(BIOS_DEBUG, "%s: Set to user date\n",
152 dev->chip_ops->name);
153 rx6110sa_set_user_date(dev);
154 } else {
155 /* Set date from coreboot build. */
156 printk(BIOS_DEBUG, "%s: Set to coreboot build date\n",
157 dev->chip_ops->name);
158 rx6110sa_set_build_date(dev);
159 }
160 rx6110sa_write(dev, HOUR_REG, 1);
161 rx6110sa_write(dev, MINUTE_REG, 0);
162 rx6110sa_write(dev, SECOND_REG, 0);
163 /* Start oscillator again as the RTC is set up now. */
164 reg = (!!config->timer_irq_en << 4) |
165 (config->timer_mode & TMR_MODE_MASK);
166 rx6110sa_write(dev, CTRL_REG, reg);
167 }
168
169 #if CONFIG(HAVE_ACPI_TABLES) && !CONFIG(RX6110SA_DISABLE_ACPI)
rx6110sa_fill_ssdt(const struct device * dev)170 static void rx6110sa_fill_ssdt(const struct device *dev)
171 {
172 struct drivers_i2c_rx6110sa_config *config = dev->chip_info;
173 const char *scope = acpi_device_scope(dev);
174 enum i2c_speed bus_speed;
175
176 if (!scope)
177 return;
178
179 switch (config->bus_speed) {
180 case I2C_SPEED_STANDARD:
181 case I2C_SPEED_FAST:
182 bus_speed = config->bus_speed;
183 break;
184 default:
185 printk(BIOS_INFO, "%s: Bus speed unsupported, fall back to %d kHz!\n",
186 dev->chip_ops->name, I2C_SPEED_STANDARD / 1000);
187 bus_speed = I2C_SPEED_STANDARD;
188 break;
189 }
190
191 struct acpi_i2c i2c = {
192 .address = dev->path.i2c.device,
193 .mode_10bit = dev->path.i2c.mode_10bit,
194 .speed = bus_speed,
195 .resource = scope,
196 };
197
198 /* Device */
199 acpigen_write_scope(scope);
200 acpigen_write_device(acpi_device_name(dev));
201 acpigen_write_name_string("_HID", RX6110SA_HID_NAME);
202 acpigen_write_name_string("_DDN", RX6110SA_HID_DESC);
203 acpigen_write_STA(acpi_device_status(dev));
204
205 /* Resources */
206 acpigen_write_name("_CRS");
207 acpigen_write_resourcetemplate_header();
208 acpi_device_write_i2c(&i2c);
209
210 acpigen_write_resourcetemplate_footer();
211
212 acpigen_pop_len(); /* Device */
213 acpigen_pop_len(); /* Scope */
214
215 printk(BIOS_INFO, "%s: %s at %s\n", acpi_device_path(dev),
216 dev->chip_ops->name, dev_path(dev));
217 }
218
rx6110sa_acpi_name(const struct device * dev)219 static const char *rx6110sa_acpi_name(const struct device *dev)
220 {
221 return RX6110SA_ACPI_NAME;
222 }
223 #endif
224
225 static struct device_operations rx6110sa_ops = {
226 .read_resources = noop_read_resources,
227 .set_resources = noop_set_resources,
228 .init = rx6110sa_init,
229 .final = rx6110sa_final,
230 #if CONFIG(HAVE_ACPI_TABLES) && !CONFIG(RX6110SA_DISABLE_ACPI)
231 .acpi_name = rx6110sa_acpi_name,
232 .acpi_fill_ssdt = rx6110sa_fill_ssdt,
233 #endif
234 };
235
rx6110sa_enable(struct device * dev)236 static void rx6110sa_enable(struct device *dev)
237 {
238 dev->ops = &rx6110sa_ops;
239 }
240
241 struct chip_operations drivers_i2c_rx6110sa_ops = {
242 .name = "RX6110 SA",
243 .enable_dev = rx6110sa_enable
244 };
245