* [PATCH] at24: support eeproms that do not roll over page reads.
@ 2017-10-30 15:48 ` Sven Van Asbroeck
0 siblings, 0 replies; 8+ messages in thread
From: Sven Van Asbroeck @ 2017-10-30 15:48 UTC (permalink / raw)
To: svendev, robh+dt, mark.rutland, wsa, nsekhar, david, javier
Cc: devicetree, linux-kernel, linux-i2c
Some eeproms in the at24 family do not roll over page reads,
e.g. the Microchip 24AA16/24LC16B. On those eeproms, reads
that straddle block boundaries will not work correctly.
Solution:
Implement read rollover in the driver. To enable it, add the
AT24_FLAG_NO_RDROL flag to the eeprom entry in the
device_id table, or add 'no-read-rollover' to the eeprom
devicetree entry.
Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
.../devicetree/bindings/eeprom/eeprom.txt | 5 +++
drivers/misc/eeprom/at24.c | 46 +++++++++++-----------
include/linux/platform_data/at24.h | 1 +
3 files changed, 28 insertions(+), 24 deletions(-)
diff --git a/Documentation/devicetree/bindings/eeprom/eeprom.txt b/Documentation/devicetree/bindings/eeprom/eeprom.txt
index afc0458..301bc7e 100644
--- a/Documentation/devicetree/bindings/eeprom/eeprom.txt
+++ b/Documentation/devicetree/bindings/eeprom/eeprom.txt
@@ -36,6 +36,11 @@ Optional properties:
- read-only: this parameterless property disables writes to the eeprom
+ - no-read-rollover: supported on the at24 eeprom family only.
+ This parameterless property indicates that the
+ eeprom does not support auto read rollover. Please consult
+ the manual of your device.
+
Example:
eeprom@52 {
diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
index 764ff5df..ef4197c 100644
--- a/drivers/misc/eeprom/at24.c
+++ b/drivers/misc/eeprom/at24.c
@@ -192,26 +192,22 @@ struct at24_data {
* set the byte address; on a multi-master board, another master
* may have changed the chip's "current" address pointer.
*
- * REVISIT some multi-address chips don't rollover page reads to
- * the next slave address, so we may need to truncate the count.
- * Those chips might need another quirk flag.
- *
- * If the real hardware used four adjacent 24c02 chips and that
- * were misconfigured as one 24c08, that would be a similar effect:
- * one "eeprom" file not four, but larger reads would fail when
- * they crossed certain pages.
+ * In case of chips that don't rollover page reads, truncate the count
+ * to the nearest page boundary. This might result in the
+ * at24_eeprom_read_XXX functions reading fewer bytes than requested,
+ * but this is compensated for in at24_read().
*/
static struct i2c_client *at24_translate_offset(struct at24_data *at24,
- unsigned int *offset)
+ unsigned int *offset, size_t *count)
{
- unsigned i;
-
- if (at24->chip.flags & AT24_FLAG_ADDR16) {
- i = *offset >> 16;
- *offset &= 0xffff;
- } else {
- i = *offset >> 8;
- *offset &= 0xff;
+ unsigned int i, bits, remainder;
+
+ bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
+ i = *offset >> bits;
+ *offset &= AT24_BITMASK(bits);
+ if ((at24->chip.flags & AT24_FLAG_NO_RDROL) && count) {
+ remainder = BIT(bits) - *offset;
+ *count = min(*count, remainder);
}
return at24->client[i];
@@ -224,7 +220,7 @@ static ssize_t at24_eeprom_read_smbus(struct at24_data *at24, char *buf,
struct i2c_client *client;
int status;
- client = at24_translate_offset(at24, &offset);
+ client = at24_translate_offset(at24, &offset, &count);
if (count > io_limit)
count = io_limit;
@@ -258,7 +254,7 @@ static ssize_t at24_eeprom_read_i2c(struct at24_data *at24, char *buf,
u8 msgbuf[2];
memset(msg, 0, sizeof(msg));
- client = at24_translate_offset(at24, &offset);
+ client = at24_translate_offset(at24, &offset, &count);
if (count > io_limit)
count = io_limit;
@@ -307,7 +303,7 @@ static ssize_t at24_eeprom_read_serial(struct at24_data *at24, char *buf,
u8 addrbuf[2];
int status;
- client = at24_translate_offset(at24, &offset);
+ client = at24_translate_offset(at24, &offset, &count);
memset(msg, 0, sizeof(msg));
msg[0].addr = client->addr;
@@ -360,7 +356,7 @@ static ssize_t at24_eeprom_read_mac(struct at24_data *at24, char *buf,
u8 addrbuf[2];
int status;
- client = at24_translate_offset(at24, &offset);
+ client = at24_translate_offset(at24, &offset, &count);
memset(msg, 0, sizeof(msg));
msg[0].addr = client->addr;
@@ -415,7 +411,7 @@ static ssize_t at24_eeprom_write_smbus_block(struct at24_data *at24,
struct i2c_client *client;
ssize_t status = 0;
- client = at24_translate_offset(at24, &offset);
+ client = at24_translate_offset(at24, &offset, NULL);
count = at24_adjust_write_count(at24, offset, count);
loop_until_timeout(timeout, write_time) {
@@ -442,7 +438,7 @@ static ssize_t at24_eeprom_write_smbus_byte(struct at24_data *at24,
struct i2c_client *client;
ssize_t status = 0;
- client = at24_translate_offset(at24, &offset);
+ client = at24_translate_offset(at24, &offset, &count);
loop_until_timeout(timeout, write_time) {
status = i2c_smbus_write_byte_data(client, offset, buf[0]);
@@ -468,7 +464,7 @@ static ssize_t at24_eeprom_write_i2c(struct at24_data *at24, const char *buf,
ssize_t status = 0;
int i = 0;
- client = at24_translate_offset(at24, &offset);
+ client = at24_translate_offset(at24, &offset, NULL);
count = at24_adjust_write_count(at24, offset, count);
msg.addr = client->addr;
@@ -569,6 +565,8 @@ static void at24_get_pdata(struct device *dev, struct at24_platform_data *chip)
if (device_property_present(dev, "read-only"))
chip->flags |= AT24_FLAG_READONLY;
+ if (device_property_present(dev, "no-read-rollover"))
+ chip->flags |= AT24_FLAG_NO_RDROL;
err = device_property_read_u32(dev, "pagesize", &val);
if (!err) {
diff --git a/include/linux/platform_data/at24.h b/include/linux/platform_data/at24.h
index 271a4e2..a5804f1 100644
--- a/include/linux/platform_data/at24.h
+++ b/include/linux/platform_data/at24.h
@@ -50,6 +50,7 @@ struct at24_platform_data {
#define AT24_FLAG_TAKE8ADDR BIT(4) /* take always 8 addresses (24c00) */
#define AT24_FLAG_SERIAL BIT(3) /* factory-programmed serial number */
#define AT24_FLAG_MAC BIT(2) /* factory-programmed mac address */
+#define AT24_FLAG_NO_RDROL BIT(1) /* chip does not rollover page reads */
void (*setup)(struct nvmem_device *nvmem, void *context);
void *context;
--
1.9.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH] at24: support eeproms that do not roll over page reads.
2017-10-30 15:48 ` Sven Van Asbroeck
@ 2017-11-01 4:16 ` kbuild test robot
-1 siblings, 0 replies; 8+ messages in thread
From: kbuild test robot @ 2017-11-01 4:16 UTC (permalink / raw)
To: Sven Van Asbroeck
Cc: kbuild-all, svendev, robh+dt, mark.rutland, wsa, nsekhar, david,
javier, devicetree, linux-kernel, linux-i2c
[-- Attachment #1: Type: text/plain, Size: 10534 bytes --]
Hi Sven,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.14-rc7]
[cannot apply to next-20171018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Sven-Van-Asbroeck/at24-support-eeproms-that-do-not-roll-over-page-reads/20171101-114231
config: sparc64-allyesconfig (attached as .config)
compiler: sparc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=sparc64
All warnings (new ones prefixed by >>):
In file included from drivers/misc/eeprom/at24.c:12:0:
drivers/misc/eeprom/at24.c: In function 'at24_translate_offset':
include/linux/kernel.h:790:16: warning: comparison of distinct pointer types lacks a cast
(void) (&min1 == &min2); \
^
include/linux/kernel.h:799:2: note: in expansion of macro '__min'
__min(typeof(x), typeof(y), \
^~~~~
>> drivers/misc/eeprom/at24.c:210:12: note: in expansion of macro 'min'
*count = min(*count, remainder);
^~~
vim +/min +210 drivers/misc/eeprom/at24.c
> 12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/delay.h>
17 #include <linux/mutex.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/log2.h>
20 #include <linux/bitops.h>
21 #include <linux/jiffies.h>
22 #include <linux/property.h>
23 #include <linux/acpi.h>
24 #include <linux/i2c.h>
25 #include <linux/nvmem-provider.h>
26 #include <linux/platform_data/at24.h>
27
28 /*
29 * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable.
30 * Differences between different vendor product lines (like Atmel AT24C or
31 * MicroChip 24LC, etc) won't much matter for typical read/write access.
32 * There are also I2C RAM chips, likewise interchangeable. One example
33 * would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes).
34 *
35 * However, misconfiguration can lose data. "Set 16-bit memory address"
36 * to a part with 8-bit addressing will overwrite data. Writing with too
37 * big a page size also loses data. And it's not safe to assume that the
38 * conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC
39 * uses 0x51, for just one example.
40 *
41 * Accordingly, explicit board-specific configuration data should be used
42 * in almost all cases. (One partial exception is an SMBus used to access
43 * "SPD" data for DRAM sticks. Those only use 24c02 EEPROMs.)
44 *
45 * So this driver uses "new style" I2C driver binding, expecting to be
46 * told what devices exist. That may be in arch/X/mach-Y/board-Z.c or
47 * similar kernel-resident tables; or, configuration data coming from
48 * a bootloader.
49 *
50 * Other than binding model, current differences from "eeprom" driver are
51 * that this one handles write access and isn't restricted to 24c02 devices.
52 * It also handles larger devices (32 kbit and up) with two-byte addresses,
53 * which won't work on pure SMBus systems.
54 */
55
56 struct at24_data {
57 struct at24_platform_data chip;
58 int use_smbus;
59 int use_smbus_write;
60
61 ssize_t (*read_func)(struct at24_data *, char *, unsigned int, size_t);
62 ssize_t (*write_func)(struct at24_data *,
63 const char *, unsigned int, size_t);
64
65 /*
66 * Lock protects against activities from other Linux tasks,
67 * but not from changes by other I2C masters.
68 */
69 struct mutex lock;
70
71 u8 *writebuf;
72 unsigned write_max;
73 unsigned num_addresses;
74
75 struct nvmem_config nvmem_config;
76 struct nvmem_device *nvmem;
77
78 /*
79 * Some chips tie up multiple I2C addresses; dummy devices reserve
80 * them for us, and we'll use them with SMBus calls.
81 */
82 struct i2c_client *client[];
83 };
84
85 /*
86 * This parameter is to help this driver avoid blocking other drivers out
87 * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C
88 * clock, one 256 byte read takes about 1/43 second which is excessive;
89 * but the 1/170 second it takes at 400 kHz may be quite reasonable; and
90 * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible.
91 *
92 * This value is forced to be a power of two so that writes align on pages.
93 */
94 static unsigned io_limit = 128;
95 module_param(io_limit, uint, 0);
96 MODULE_PARM_DESC(io_limit, "Maximum bytes per I/O (default 128)");
97
98 /*
99 * Specs often allow 5 msec for a page write, sometimes 20 msec;
100 * it's important to recover from write timeouts.
101 */
102 static unsigned write_timeout = 25;
103 module_param(write_timeout, uint, 0);
104 MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
105
106 #define AT24_SIZE_BYTELEN 5
107 #define AT24_SIZE_FLAGS 8
108
109 #define AT24_BITMASK(x) (BIT(x) - 1)
110
111 /* create non-zero magic value for given eeprom parameters */
112 #define AT24_DEVICE_MAGIC(_len, _flags) \
113 ((1 << AT24_SIZE_FLAGS | (_flags)) \
114 << AT24_SIZE_BYTELEN | ilog2(_len))
115
116 /*
117 * Both reads and writes fail if the previous write didn't complete yet. This
118 * macro loops a few times waiting at least long enough for one entire page
119 * write to work while making sure that at least one iteration is run before
120 * checking the break condition.
121 *
122 * It takes two parameters: a variable in which the future timeout in jiffies
123 * will be stored and a temporary variable holding the time of the last
124 * iteration of processing the request. Both should be unsigned integers
125 * holding at least 32 bits.
126 */
127 #define loop_until_timeout(tout, op_time) \
128 for (tout = jiffies + msecs_to_jiffies(write_timeout), op_time = 0; \
129 op_time ? time_before(op_time, tout) : true; \
130 usleep_range(1000, 1500), op_time = jiffies)
131
132 static const struct i2c_device_id at24_ids[] = {
133 /* needs 8 addresses as A0-A2 are ignored */
134 { "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) },
135 /* old variants can't be handled with this generic entry! */
136 { "24c01", AT24_DEVICE_MAGIC(1024 / 8, 0) },
137 { "24cs01", AT24_DEVICE_MAGIC(16,
138 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
139 { "24c02", AT24_DEVICE_MAGIC(2048 / 8, 0) },
140 { "24cs02", AT24_DEVICE_MAGIC(16,
141 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
142 { "24mac402", AT24_DEVICE_MAGIC(48 / 8,
143 AT24_FLAG_MAC | AT24_FLAG_READONLY) },
144 { "24mac602", AT24_DEVICE_MAGIC(64 / 8,
145 AT24_FLAG_MAC | AT24_FLAG_READONLY) },
146 /* spd is a 24c02 in memory DIMMs */
147 { "spd", AT24_DEVICE_MAGIC(2048 / 8,
148 AT24_FLAG_READONLY | AT24_FLAG_IRUGO) },
149 { "24c04", AT24_DEVICE_MAGIC(4096 / 8, 0) },
150 { "24cs04", AT24_DEVICE_MAGIC(16,
151 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
152 /* 24rf08 quirk is handled at i2c-core */
153 { "24c08", AT24_DEVICE_MAGIC(8192 / 8, 0) },
154 { "24cs08", AT24_DEVICE_MAGIC(16,
155 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
156 { "24c16", AT24_DEVICE_MAGIC(16384 / 8, 0) },
157 { "24cs16", AT24_DEVICE_MAGIC(16,
158 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
159 { "24c32", AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16) },
160 { "24cs32", AT24_DEVICE_MAGIC(16,
161 AT24_FLAG_ADDR16 |
162 AT24_FLAG_SERIAL |
163 AT24_FLAG_READONLY) },
164 { "24c64", AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16) },
165 { "24cs64", AT24_DEVICE_MAGIC(16,
166 AT24_FLAG_ADDR16 |
167 AT24_FLAG_SERIAL |
168 AT24_FLAG_READONLY) },
169 { "24c128", AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16) },
170 { "24c256", AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16) },
171 { "24c512", AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16) },
172 { "24c1024", AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16) },
173 { "at24", 0 },
174 { /* END OF LIST */ }
175 };
176 MODULE_DEVICE_TABLE(i2c, at24_ids);
177
178 static const struct acpi_device_id at24_acpi_ids[] = {
179 { "INT3499", AT24_DEVICE_MAGIC(8192 / 8, 0) },
180 { }
181 };
182 MODULE_DEVICE_TABLE(acpi, at24_acpi_ids);
183
184 /*-------------------------------------------------------------------------*/
185
186 /*
187 * This routine supports chips which consume multiple I2C addresses. It
188 * computes the addressing information to be used for a given r/w request.
189 * Assumes that sanity checks for offset happened at sysfs-layer.
190 *
191 * Slave address and byte offset derive from the offset. Always
192 * set the byte address; on a multi-master board, another master
193 * may have changed the chip's "current" address pointer.
194 *
195 * In case of chips that don't rollover page reads, truncate the count
196 * to the nearest page boundary. This might result in the
197 * at24_eeprom_read_XXX functions reading fewer bytes than requested,
198 * but this is compensated for in at24_read().
199 */
200 static struct i2c_client *at24_translate_offset(struct at24_data *at24,
201 unsigned int *offset, size_t *count)
202 {
203 unsigned int i, bits, remainder;
204
205 bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
206 i = *offset >> bits;
207 *offset &= AT24_BITMASK(bits);
208 if ((at24->chip.flags & AT24_FLAG_NO_RDROL) && count) {
209 remainder = BIT(bits) - *offset;
> 210 *count = min(*count, remainder);
211 }
212
213 return at24->client[i];
214 }
215
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 52060 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] at24: support eeproms that do not roll over page reads.
@ 2017-11-01 4:16 ` kbuild test robot
0 siblings, 0 replies; 8+ messages in thread
From: kbuild test robot @ 2017-11-01 4:16 UTC (permalink / raw)
Cc: kbuild-all, svendev, robh+dt, mark.rutland, wsa, nsekhar, david,
javier, devicetree, linux-kernel, linux-i2c
[-- Attachment #1: Type: text/plain, Size: 10534 bytes --]
Hi Sven,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.14-rc7]
[cannot apply to next-20171018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Sven-Van-Asbroeck/at24-support-eeproms-that-do-not-roll-over-page-reads/20171101-114231
config: sparc64-allyesconfig (attached as .config)
compiler: sparc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=sparc64
All warnings (new ones prefixed by >>):
In file included from drivers/misc/eeprom/at24.c:12:0:
drivers/misc/eeprom/at24.c: In function 'at24_translate_offset':
include/linux/kernel.h:790:16: warning: comparison of distinct pointer types lacks a cast
(void) (&min1 == &min2); \
^
include/linux/kernel.h:799:2: note: in expansion of macro '__min'
__min(typeof(x), typeof(y), \
^~~~~
>> drivers/misc/eeprom/at24.c:210:12: note: in expansion of macro 'min'
*count = min(*count, remainder);
^~~
vim +/min +210 drivers/misc/eeprom/at24.c
> 12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/delay.h>
17 #include <linux/mutex.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/log2.h>
20 #include <linux/bitops.h>
21 #include <linux/jiffies.h>
22 #include <linux/property.h>
23 #include <linux/acpi.h>
24 #include <linux/i2c.h>
25 #include <linux/nvmem-provider.h>
26 #include <linux/platform_data/at24.h>
27
28 /*
29 * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable.
30 * Differences between different vendor product lines (like Atmel AT24C or
31 * MicroChip 24LC, etc) won't much matter for typical read/write access.
32 * There are also I2C RAM chips, likewise interchangeable. One example
33 * would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes).
34 *
35 * However, misconfiguration can lose data. "Set 16-bit memory address"
36 * to a part with 8-bit addressing will overwrite data. Writing with too
37 * big a page size also loses data. And it's not safe to assume that the
38 * conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC
39 * uses 0x51, for just one example.
40 *
41 * Accordingly, explicit board-specific configuration data should be used
42 * in almost all cases. (One partial exception is an SMBus used to access
43 * "SPD" data for DRAM sticks. Those only use 24c02 EEPROMs.)
44 *
45 * So this driver uses "new style" I2C driver binding, expecting to be
46 * told what devices exist. That may be in arch/X/mach-Y/board-Z.c or
47 * similar kernel-resident tables; or, configuration data coming from
48 * a bootloader.
49 *
50 * Other than binding model, current differences from "eeprom" driver are
51 * that this one handles write access and isn't restricted to 24c02 devices.
52 * It also handles larger devices (32 kbit and up) with two-byte addresses,
53 * which won't work on pure SMBus systems.
54 */
55
56 struct at24_data {
57 struct at24_platform_data chip;
58 int use_smbus;
59 int use_smbus_write;
60
61 ssize_t (*read_func)(struct at24_data *, char *, unsigned int, size_t);
62 ssize_t (*write_func)(struct at24_data *,
63 const char *, unsigned int, size_t);
64
65 /*
66 * Lock protects against activities from other Linux tasks,
67 * but not from changes by other I2C masters.
68 */
69 struct mutex lock;
70
71 u8 *writebuf;
72 unsigned write_max;
73 unsigned num_addresses;
74
75 struct nvmem_config nvmem_config;
76 struct nvmem_device *nvmem;
77
78 /*
79 * Some chips tie up multiple I2C addresses; dummy devices reserve
80 * them for us, and we'll use them with SMBus calls.
81 */
82 struct i2c_client *client[];
83 };
84
85 /*
86 * This parameter is to help this driver avoid blocking other drivers out
87 * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C
88 * clock, one 256 byte read takes about 1/43 second which is excessive;
89 * but the 1/170 second it takes at 400 kHz may be quite reasonable; and
90 * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible.
91 *
92 * This value is forced to be a power of two so that writes align on pages.
93 */
94 static unsigned io_limit = 128;
95 module_param(io_limit, uint, 0);
96 MODULE_PARM_DESC(io_limit, "Maximum bytes per I/O (default 128)");
97
98 /*
99 * Specs often allow 5 msec for a page write, sometimes 20 msec;
100 * it's important to recover from write timeouts.
101 */
102 static unsigned write_timeout = 25;
103 module_param(write_timeout, uint, 0);
104 MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)");
105
106 #define AT24_SIZE_BYTELEN 5
107 #define AT24_SIZE_FLAGS 8
108
109 #define AT24_BITMASK(x) (BIT(x) - 1)
110
111 /* create non-zero magic value for given eeprom parameters */
112 #define AT24_DEVICE_MAGIC(_len, _flags) \
113 ((1 << AT24_SIZE_FLAGS | (_flags)) \
114 << AT24_SIZE_BYTELEN | ilog2(_len))
115
116 /*
117 * Both reads and writes fail if the previous write didn't complete yet. This
118 * macro loops a few times waiting at least long enough for one entire page
119 * write to work while making sure that at least one iteration is run before
120 * checking the break condition.
121 *
122 * It takes two parameters: a variable in which the future timeout in jiffies
123 * will be stored and a temporary variable holding the time of the last
124 * iteration of processing the request. Both should be unsigned integers
125 * holding at least 32 bits.
126 */
127 #define loop_until_timeout(tout, op_time) \
128 for (tout = jiffies + msecs_to_jiffies(write_timeout), op_time = 0; \
129 op_time ? time_before(op_time, tout) : true; \
130 usleep_range(1000, 1500), op_time = jiffies)
131
132 static const struct i2c_device_id at24_ids[] = {
133 /* needs 8 addresses as A0-A2 are ignored */
134 { "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) },
135 /* old variants can't be handled with this generic entry! */
136 { "24c01", AT24_DEVICE_MAGIC(1024 / 8, 0) },
137 { "24cs01", AT24_DEVICE_MAGIC(16,
138 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
139 { "24c02", AT24_DEVICE_MAGIC(2048 / 8, 0) },
140 { "24cs02", AT24_DEVICE_MAGIC(16,
141 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
142 { "24mac402", AT24_DEVICE_MAGIC(48 / 8,
143 AT24_FLAG_MAC | AT24_FLAG_READONLY) },
144 { "24mac602", AT24_DEVICE_MAGIC(64 / 8,
145 AT24_FLAG_MAC | AT24_FLAG_READONLY) },
146 /* spd is a 24c02 in memory DIMMs */
147 { "spd", AT24_DEVICE_MAGIC(2048 / 8,
148 AT24_FLAG_READONLY | AT24_FLAG_IRUGO) },
149 { "24c04", AT24_DEVICE_MAGIC(4096 / 8, 0) },
150 { "24cs04", AT24_DEVICE_MAGIC(16,
151 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
152 /* 24rf08 quirk is handled at i2c-core */
153 { "24c08", AT24_DEVICE_MAGIC(8192 / 8, 0) },
154 { "24cs08", AT24_DEVICE_MAGIC(16,
155 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
156 { "24c16", AT24_DEVICE_MAGIC(16384 / 8, 0) },
157 { "24cs16", AT24_DEVICE_MAGIC(16,
158 AT24_FLAG_SERIAL | AT24_FLAG_READONLY) },
159 { "24c32", AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16) },
160 { "24cs32", AT24_DEVICE_MAGIC(16,
161 AT24_FLAG_ADDR16 |
162 AT24_FLAG_SERIAL |
163 AT24_FLAG_READONLY) },
164 { "24c64", AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16) },
165 { "24cs64", AT24_DEVICE_MAGIC(16,
166 AT24_FLAG_ADDR16 |
167 AT24_FLAG_SERIAL |
168 AT24_FLAG_READONLY) },
169 { "24c128", AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16) },
170 { "24c256", AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16) },
171 { "24c512", AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16) },
172 { "24c1024", AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16) },
173 { "at24", 0 },
174 { /* END OF LIST */ }
175 };
176 MODULE_DEVICE_TABLE(i2c, at24_ids);
177
178 static const struct acpi_device_id at24_acpi_ids[] = {
179 { "INT3499", AT24_DEVICE_MAGIC(8192 / 8, 0) },
180 { }
181 };
182 MODULE_DEVICE_TABLE(acpi, at24_acpi_ids);
183
184 /*-------------------------------------------------------------------------*/
185
186 /*
187 * This routine supports chips which consume multiple I2C addresses. It
188 * computes the addressing information to be used for a given r/w request.
189 * Assumes that sanity checks for offset happened at sysfs-layer.
190 *
191 * Slave address and byte offset derive from the offset. Always
192 * set the byte address; on a multi-master board, another master
193 * may have changed the chip's "current" address pointer.
194 *
195 * In case of chips that don't rollover page reads, truncate the count
196 * to the nearest page boundary. This might result in the
197 * at24_eeprom_read_XXX functions reading fewer bytes than requested,
198 * but this is compensated for in at24_read().
199 */
200 static struct i2c_client *at24_translate_offset(struct at24_data *at24,
201 unsigned int *offset, size_t *count)
202 {
203 unsigned int i, bits, remainder;
204
205 bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
206 i = *offset >> bits;
207 *offset &= AT24_BITMASK(bits);
208 if ((at24->chip.flags & AT24_FLAG_NO_RDROL) && count) {
209 remainder = BIT(bits) - *offset;
> 210 *count = min(*count, remainder);
211 }
212
213 return at24->client[i];
214 }
215
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 52060 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] at24: support eeproms that do not roll over page reads.
@ 2017-11-01 4:29 ` kbuild test robot
0 siblings, 0 replies; 8+ messages in thread
From: kbuild test robot @ 2017-11-01 4:29 UTC (permalink / raw)
To: Sven Van Asbroeck
Cc: kbuild-all, svendev, robh+dt, mark.rutland, wsa, nsekhar, david,
javier, devicetree, linux-kernel, linux-i2c
[-- Attachment #1: Type: text/plain, Size: 2461 bytes --]
Hi Sven,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.14-rc7]
[cannot apply to next-20171018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Sven-Van-Asbroeck/at24-support-eeproms-that-do-not-roll-over-page-reads/20171101-114231
config: tile-allyesconfig (attached as .config)
compiler: tilegx-linux-gcc (GCC) 4.6.2
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=tile
All warnings (new ones prefixed by >>):
drivers/misc/eeprom/at24.c: In function 'at24_translate_offset':
>> drivers/misc/eeprom/at24.c:210:12: warning: comparison of distinct pointer types lacks a cast [enabled by default]
vim +210 drivers/misc/eeprom/at24.c
185
186 /*
187 * This routine supports chips which consume multiple I2C addresses. It
188 * computes the addressing information to be used for a given r/w request.
189 * Assumes that sanity checks for offset happened at sysfs-layer.
190 *
191 * Slave address and byte offset derive from the offset. Always
192 * set the byte address; on a multi-master board, another master
193 * may have changed the chip's "current" address pointer.
194 *
195 * In case of chips that don't rollover page reads, truncate the count
196 * to the nearest page boundary. This might result in the
197 * at24_eeprom_read_XXX functions reading fewer bytes than requested,
198 * but this is compensated for in at24_read().
199 */
200 static struct i2c_client *at24_translate_offset(struct at24_data *at24,
201 unsigned int *offset, size_t *count)
202 {
203 unsigned int i, bits, remainder;
204
205 bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
206 i = *offset >> bits;
207 *offset &= AT24_BITMASK(bits);
208 if ((at24->chip.flags & AT24_FLAG_NO_RDROL) && count) {
209 remainder = BIT(bits) - *offset;
> 210 *count = min(*count, remainder);
211 }
212
213 return at24->client[i];
214 }
215
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 50480 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] at24: support eeproms that do not roll over page reads.
@ 2017-11-01 4:29 ` kbuild test robot
0 siblings, 0 replies; 8+ messages in thread
From: kbuild test robot @ 2017-11-01 4:29 UTC (permalink / raw)
Cc: kbuild-all-JC7UmRfGjtg, svendev-fuHqz3Nb1YI,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A, mark.rutland-5wv7dgnIgG8,
wsa-z923LK4zBo2bacvFa/9K2g, nsekhar-l0cyMroinI0,
david-nq/r/kbU++upp/zk7JDF2g, javier-0uQlZySMnqxg9hUCZPvPmw,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
[-- Attachment #1: Type: text/plain, Size: 2461 bytes --]
Hi Sven,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.14-rc7]
[cannot apply to next-20171018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Sven-Van-Asbroeck/at24-support-eeproms-that-do-not-roll-over-page-reads/20171101-114231
config: tile-allyesconfig (attached as .config)
compiler: tilegx-linux-gcc (GCC) 4.6.2
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=tile
All warnings (new ones prefixed by >>):
drivers/misc/eeprom/at24.c: In function 'at24_translate_offset':
>> drivers/misc/eeprom/at24.c:210:12: warning: comparison of distinct pointer types lacks a cast [enabled by default]
vim +210 drivers/misc/eeprom/at24.c
185
186 /*
187 * This routine supports chips which consume multiple I2C addresses. It
188 * computes the addressing information to be used for a given r/w request.
189 * Assumes that sanity checks for offset happened at sysfs-layer.
190 *
191 * Slave address and byte offset derive from the offset. Always
192 * set the byte address; on a multi-master board, another master
193 * may have changed the chip's "current" address pointer.
194 *
195 * In case of chips that don't rollover page reads, truncate the count
196 * to the nearest page boundary. This might result in the
197 * at24_eeprom_read_XXX functions reading fewer bytes than requested,
198 * but this is compensated for in at24_read().
199 */
200 static struct i2c_client *at24_translate_offset(struct at24_data *at24,
201 unsigned int *offset, size_t *count)
202 {
203 unsigned int i, bits, remainder;
204
205 bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
206 i = *offset >> bits;
207 *offset &= AT24_BITMASK(bits);
208 if ((at24->chip.flags & AT24_FLAG_NO_RDROL) && count) {
209 remainder = BIT(bits) - *offset;
> 210 *count = min(*count, remainder);
211 }
212
213 return at24->client[i];
214 }
215
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 50480 bytes --]
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH] at24: support eeproms that do not roll over page reads.
@ 2017-11-01 6:22 ` kbuild test robot
0 siblings, 0 replies; 8+ messages in thread
From: kbuild test robot @ 2017-11-01 6:22 UTC (permalink / raw)
To: Sven Van Asbroeck
Cc: kbuild-all, svendev, robh+dt, mark.rutland, wsa, nsekhar, david,
javier, devicetree, linux-kernel, linux-i2c
Hi Sven,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.14-rc7]
[cannot apply to next-20171018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Sven-Van-Asbroeck/at24-support-eeproms-that-do-not-roll-over-page-reads/20171101-114231
reproduce:
# apt-get install sparse
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__
sparse warnings: (new ones prefixed by >>)
vim +210 drivers/misc/eeprom/at24.c
185
186 /*
187 * This routine supports chips which consume multiple I2C addresses. It
188 * computes the addressing information to be used for a given r/w request.
189 * Assumes that sanity checks for offset happened at sysfs-layer.
190 *
191 * Slave address and byte offset derive from the offset. Always
192 * set the byte address; on a multi-master board, another master
193 * may have changed the chip's "current" address pointer.
194 *
195 * In case of chips that don't rollover page reads, truncate the count
196 * to the nearest page boundary. This might result in the
197 * at24_eeprom_read_XXX functions reading fewer bytes than requested,
198 * but this is compensated for in at24_read().
199 */
200 static struct i2c_client *at24_translate_offset(struct at24_data *at24,
201 unsigned int *offset, size_t *count)
202 {
203 unsigned int i, bits, remainder;
204
205 bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
206 i = *offset >> bits;
207 *offset &= AT24_BITMASK(bits);
208 if ((at24->chip.flags & AT24_FLAG_NO_RDROL) && count) {
209 remainder = BIT(bits) - *offset;
> 210 *count = min(*count, remainder);
211 }
212
213 return at24->client[i];
214 }
215
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH] at24: support eeproms that do not roll over page reads.
@ 2017-11-01 6:22 ` kbuild test robot
0 siblings, 0 replies; 8+ messages in thread
From: kbuild test robot @ 2017-11-01 6:22 UTC (permalink / raw)
Cc: kbuild-all-JC7UmRfGjtg, svendev-fuHqz3Nb1YI,
robh+dt-DgEjT+Ai2ygdnm+yROfE0A, mark.rutland-5wv7dgnIgG8,
wsa-z923LK4zBo2bacvFa/9K2g, nsekhar-l0cyMroinI0,
david-nq/r/kbU++upp/zk7JDF2g, javier-0uQlZySMnqxg9hUCZPvPmw,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-i2c-u79uwXL29TY76Z2rM5mHXA
Hi Sven,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on linus/master]
[also build test WARNING on v4.14-rc7]
[cannot apply to next-20171018]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Sven-Van-Asbroeck/at24-support-eeproms-that-do-not-roll-over-page-reads/20171101-114231
reproduce:
# apt-get install sparse
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__
sparse warnings: (new ones prefixed by >>)
vim +210 drivers/misc/eeprom/at24.c
185
186 /*
187 * This routine supports chips which consume multiple I2C addresses. It
188 * computes the addressing information to be used for a given r/w request.
189 * Assumes that sanity checks for offset happened at sysfs-layer.
190 *
191 * Slave address and byte offset derive from the offset. Always
192 * set the byte address; on a multi-master board, another master
193 * may have changed the chip's "current" address pointer.
194 *
195 * In case of chips that don't rollover page reads, truncate the count
196 * to the nearest page boundary. This might result in the
197 * at24_eeprom_read_XXX functions reading fewer bytes than requested,
198 * but this is compensated for in at24_read().
199 */
200 static struct i2c_client *at24_translate_offset(struct at24_data *at24,
201 unsigned int *offset, size_t *count)
202 {
203 unsigned int i, bits, remainder;
204
205 bits = (at24->chip.flags & AT24_FLAG_ADDR16) ? 16 : 8;
206 i = *offset >> bits;
207 *offset &= AT24_BITMASK(bits);
208 if ((at24->chip.flags & AT24_FLAG_NO_RDROL) && count) {
209 remainder = BIT(bits) - *offset;
> 210 *count = min(*count, remainder);
211 }
212
213 return at24->client[i];
214 }
215
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply [flat|nested] 8+ messages in thread