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[2a01:c22:77a7:1500:6165:f4a3:e866:218b]) by smtp.googlemail.com with ESMTPSA id a26-20020a17090640da00b009e651700b92sm8480123ejk.124.2023.11.16.06.31.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 16 Nov 2023 06:32:00 -0800 (PST) Message-ID: Date: Thu, 16 Nov 2023 15:31:59 +0100 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Content-Language: en-US To: Jean Delvare , Arnd Bergmann , Greg Kroah-Hartman Cc: "linux-i2c@vger.kernel.org" From: Heiner Kallweit Subject: [PATCH v2] eeprom: ee1004: Add support for multiple i2c busses Autocrypt: addr=hkallweit1@gmail.com; keydata= xsFNBF/0ZFUBEAC0eZyktSE7ZNO1SFXL6cQ4i4g6Ah3mOUIXSB4pCY5kQ6OLKHh0FlOD5/5/ sY7IoIouzOjyFdFPnz4Bl3927ClT567hUJJ+SNaFEiJ9vadI6vZm2gcY4ExdIevYHWe1msJF MVE4yNwdS+UsPeCF/6CQQTzHc+n7DomE7fjJD5J1hOJjqz2XWe71fTvYXzxCFLwXXbBiqDC9 dNqOe5odPsa4TsWZ09T33g5n2nzTJs4Zw8fCy8rLqix/raVsqr8fw5qM66MVtdmEljFaJ9N8 /W56qGCp+H8Igk/F7CjlbWXiOlKHA25mPTmbVp7VlFsvsmMokr/imQr+0nXtmvYVaKEUwY2g 86IU6RAOuA8E0J5bD/BeyZdMyVEtX1kT404UJZekFytJZrDZetwxM/cAH+1fMx4z751WJmxQ J7mIXSPuDfeJhRDt9sGM6aRVfXbZt+wBogxyXepmnlv9K4A13z9DVLdKLrYUiu9/5QEl6fgI kPaXlAZmJsQfoKbmPqCHVRYj1lpQtDM/2/BO6gHASflWUHzwmBVZbS/XRs64uJO8CB3+V3fa cIivllReueGCMsHh6/8wgPAyopXOWOxbLsZ291fmZqIR0L5Y6b2HvdFN1Xhc+YrQ8TKK+Z4R mJRDh0wNQ8Gm89g92/YkHji4jIWlp2fwzCcx5+lZCQ1XdqAiHQARAQABzSZIZWluZXIgS2Fs bHdlaXQgPGhrYWxsd2VpdDFAZ21haWwuY29tPsLBjgQTAQgAOBYhBGxfqY/yOyXjyjJehXLe ig9U8DoMBQJf9GRVAhsDBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAAoJEHLeig9U8DoMSycQ AJbfg8HZEK0ljV4M8nvdaiNixWAufrcZ+SD8zhbxl8GispK4F3Yo+20Y3UoZ7FcIidJWUUJL axAOkpI/70YNhlqAPMsuudlAieeYZKjIv1WV5ucNZ3VJ7dC+dlVqQdAr1iD869FZXvy91KhJ wYulyCf+s4T9YgmLC6jLMBZghKIf1uhSd0NzjyCqYWbk2ZxByZHgunEShOhHPHswu3Am0ftt ePaYIHgZs+Vzwfjs8I7EuW/5/f5G9w1vibXxtGY/GXwgGGHRDjFM7RSprGOv4F5eMGh+NFUJ TU9N96PQYMwXVxnQfRXl8O6ffSVmFx4H9rovxWPKobLmqQL0WKLLVvA/aOHCcMKgfyKRcLah 57vGC50Ga8oT2K1g0AhKGkyJo7lGXkMu5yEs0m9O+btqAB261/E3DRxfI1P/tvDZpLJKtq35 dXsj6sjvhgX7VxXhY1wE54uqLLHY3UZQlmH3QF5t80MS7/KhxB1pO1Cpcmkt9hgyzH8+5org +9wWxGUtJWNP7CppY+qvv3SZtKJMKsxqk5coBGwNkMms56z4qfJm2PUtJQGjA65XWdzQACib 2iaDQoBqGZfXRdPT0tC1H5kUJuOX4ll1hI/HBMEFCcO8++Bl2wcrUsAxLzGvhINVJX2DAQaF aNetToazkCnzubKfBOyiTqFJ0b63c5dqziAgzsFNBF/0ZFUBEADF8UEZmKDl1w/UxvjeyAeX kghYkY3bkK6gcIYXdLRfJw12GbvMioSguvVzASVHG8h7NbNjk1yur6AONfbUpXKSNZ0skV8V fG+ppbaY+zQofsSMoj5gP0amwbwvPzVqZCYJai81VobefTX2MZM2Mg/ThBVtGyzV3NeCpnBa 8AX3s9rrX2XUoCibYotbbxx9afZYUFyflOc7kEpc9uJXIdaxS2Z6MnYLHsyVjiU6tzKCiVOU KJevqvzPXJmy0xaOVf7mhFSNQyJTrZpLa+tvB1DQRS08CqYtIMxRrVtC0t0LFeQGly6bOngr ircurWJiJKbSXVstLHgWYiq3/GmCSx/82ObeLO3PftklpRj8d+kFbrvrqBgjWtMH4WtK5uN5 1WJ71hWJfNchKRlaJ3GWy8KolCAoGsQMovn/ZEXxrGs1ndafu47yXOpuDAozoHTBGvuSXSZo ythk/0EAuz5IkwkhYBT1MGIAvNSn9ivE5aRnBazugy0rTRkVggHvt3/7flFHlGVGpBHxFUwb /a4UjJBPtIwa4tWR8B1Ma36S8Jk456k2n1id7M0LQ+eqstmp6Y+UB+pt9NX6t0Slw1NCdYTW gJezWTVKF7pmTdXszXGxlc9kTrVUz04PqPjnYbv5UWuDd2eyzGjrrFOsJEi8OK2d2j4FfF++ AzOMdW09JVqejQARAQABwsF2BBgBCAAgFiEEbF+pj/I7JePKMl6Fct6KD1TwOgwFAl/0ZFUC GwwACgkQct6KD1TwOgxUfg//eAoYc0Vm4NrxymfcY30UjHVD0LgSvU8kUmXxil3qhFPS7KA+ y7tgcKLHOkZkXMX5MLFcS9+SmrAjSBBV8omKoHNo+kfFx/dUAtz0lot8wNGmWb+NcHeKM1eb nwUMOEa1uDdfZeKef/U/2uHBceY7Gc6zPZPWgXghEyQMTH2UhLgeam8yglyO+A6RXCh+s6ak Wje7Vo1wGK4eYxp6pwMPJXLMsI0ii/2k3YPEJPv+yJf90MbYyQSbkTwZhrsokjQEaIfjrIk3 rQRjTve/J62WIO28IbY/mENuGgWehRlTAbhC4BLTZ5uYS0YMQCR7v9UGMWdNWXFyrOB6PjSu Trn9MsPoUc8qI72mVpxEXQDLlrd2ijEWm7Nrf52YMD7hL6rXXuis7R6zY8WnnBhW0uCfhajx q+KuARXC0sDLztcjaS3ayXonpoCPZep2Bd5xqE4Ln8/COCslP7E92W1uf1EcdXXIrx1acg21 H/0Z53okMykVs3a8tECPHIxnre2UxKdTbCEkjkR4V6JyplTS47oWMw3zyI7zkaadfzVFBxk2 lo/Tny+FX1Azea3Ce7oOnRUEZtWSsUidtIjmL8YUQFZYm+JUIgfRmSpMFq8JP4VH43GXpB/S OCrl+/xujzvoUBFV/cHKjEQYBxo+MaiQa1U54ykM2W4DnHb1UiEf5xDkFd4= There are systems with more than 8 memory slots where the i2c bus for SPD is multiplexed. i2c_register_spd() isn't used yet on such systems, but it's planned. So we need to extend ee1004 accordingly. With this extension a maximum of 8 i2c busses is supported. I don't have such a system for testing, therefore I just verified that the driver still works on a system with a single i2c bus. For the sake of simplicity the extension uses the existing global mutex to protect access on all busses. This could be improved, but we support 8 busses only, and SPD data is small and rarely accessed, so it shouldn't be a problem. Signed-off-by: Heiner Kallweit --- v2: - simplify code by using i2c_set/get_clientdata --- drivers/misc/eeprom/ee1004.c | 94 ++++++++++++++++++++++++------------ 1 file changed, 63 insertions(+), 31 deletions(-) diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c index a1acd7713..fd12ce06a 100644 --- a/drivers/misc/eeprom/ee1004.c +++ b/drivers/misc/eeprom/ee1004.c @@ -31,6 +31,7 @@ * over performance. */ +#define EE1004_MAX_BUSSES 8 #define EE1004_ADDR_SET_PAGE 0x36 #define EE1004_NUM_PAGES 2 #define EE1004_PAGE_SIZE 256 @@ -42,9 +43,13 @@ * from page selection to end of read. */ static DEFINE_MUTEX(ee1004_bus_lock); -static struct i2c_client *ee1004_set_page[EE1004_NUM_PAGES]; -static unsigned int ee1004_dev_count; -static int ee1004_current_page; + +static struct ee1004_bus_data { + struct i2c_adapter *adap; + struct i2c_client *set_page[EE1004_NUM_PAGES]; + unsigned int dev_count; + int current_page; +} ee1004_bus_data[EE1004_MAX_BUSSES]; static const struct i2c_device_id ee1004_ids[] = { { "ee1004", 0 }, @@ -54,11 +59,29 @@ MODULE_DEVICE_TABLE(i2c, ee1004_ids); /*-------------------------------------------------------------------------*/ -static int ee1004_get_current_page(void) +static struct ee1004_bus_data *ee1004_get_bus_data(struct i2c_adapter *adap) +{ + int i; + + for (i = 0; i < EE1004_MAX_BUSSES; i++) + if (ee1004_bus_data[i].adap == adap) + return ee1004_bus_data + i; + + /* If not existent yet, create new entry */ + for (i = 0; i < EE1004_MAX_BUSSES; i++) + if (!ee1004_bus_data[i].adap) { + ee1004_bus_data[i].adap = adap; + return ee1004_bus_data + i; + } + + return NULL; +} + +static int ee1004_get_current_page(struct ee1004_bus_data *bd) { int err; - err = i2c_smbus_read_byte(ee1004_set_page[0]); + err = i2c_smbus_read_byte(bd->set_page[0]); if (err == -ENXIO) { /* Nack means page 1 is selected */ return 1; @@ -72,28 +95,29 @@ static int ee1004_get_current_page(void) return 0; } -static int ee1004_set_current_page(struct device *dev, int page) +static int ee1004_set_current_page(struct i2c_client *client, int page) { + struct ee1004_bus_data *bd = i2c_get_clientdata(client); int ret; - if (page == ee1004_current_page) + if (page == bd->current_page) return 0; /* Data is ignored */ - ret = i2c_smbus_write_byte(ee1004_set_page[page], 0x00); + ret = i2c_smbus_write_byte(bd->set_page[page], 0x00); /* * Don't give up just yet. Some memory modules will select the page * but not ack the command. Check which page is selected now. */ - if (ret == -ENXIO && ee1004_get_current_page() == page) + if (ret == -ENXIO && ee1004_get_current_page(bd) == page) ret = 0; if (ret < 0) { - dev_err(dev, "Failed to select page %d (%d)\n", page, ret); + dev_err(&client->dev, "Failed to select page %d (%d)\n", page, ret); return ret; } - dev_dbg(dev, "Selected page %d\n", page); - ee1004_current_page = page; + dev_dbg(&client->dev, "Selected page %d\n", page); + bd->current_page = page; return 0; } @@ -106,7 +130,7 @@ static ssize_t ee1004_eeprom_read(struct i2c_client *client, char *buf, page = offset >> EE1004_PAGE_SHIFT; offset &= (1 << EE1004_PAGE_SHIFT) - 1; - status = ee1004_set_current_page(&client->dev, page); + status = ee1004_set_current_page(client, page); if (status) return status; @@ -158,17 +182,18 @@ static struct bin_attribute *ee1004_attrs[] = { BIN_ATTRIBUTE_GROUPS(ee1004); -static void ee1004_cleanup(int idx) +static void ee1004_cleanup(int idx, struct ee1004_bus_data *bd) { - if (--ee1004_dev_count == 0) - while (--idx >= 0) { - i2c_unregister_device(ee1004_set_page[idx]); - ee1004_set_page[idx] = NULL; - } + if (--bd->dev_count == 0) { + while (--idx >= 0) + i2c_unregister_device(bd->set_page[idx]); + memset(bd, 0, sizeof(struct ee1004_bus_data)); + } } static int ee1004_probe(struct i2c_client *client) { + struct ee1004_bus_data *bd; int err, cnr = 0; /* Make sure we can operate on this adapter */ @@ -178,9 +203,19 @@ static int ee1004_probe(struct i2c_client *client) I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_READ_BYTE_DATA)) return -EPFNOSUPPORT; - /* Use 2 dummy devices for page select command */ mutex_lock(&ee1004_bus_lock); - if (++ee1004_dev_count == 1) { + + bd = ee1004_get_bus_data(client->adapter); + if (!bd) { + mutex_unlock(&ee1004_bus_lock); + return dev_err_probe(&client->dev, -ENOSPC, + "Only %d busses supported", EE1004_MAX_BUSSES); + } + + i2c_set_clientdata(client, bd); + + if (++bd->dev_count == 1) { + /* Use 2 dummy devices for page select command */ for (cnr = 0; cnr < EE1004_NUM_PAGES; cnr++) { struct i2c_client *cl; @@ -189,20 +224,15 @@ static int ee1004_probe(struct i2c_client *client) err = PTR_ERR(cl); goto err_clients; } - ee1004_set_page[cnr] = cl; + bd->set_page[cnr] = cl; } /* Remember current page to avoid unneeded page select */ - err = ee1004_get_current_page(); + err = ee1004_get_current_page(bd); if (err < 0) goto err_clients; dev_dbg(&client->dev, "Currently selected page: %d\n", err); - ee1004_current_page = err; - } else if (client->adapter != ee1004_set_page[0]->adapter) { - dev_err(&client->dev, - "Driver only supports devices on a single I2C bus\n"); - err = -EOPNOTSUPP; - goto err_clients; + bd->current_page = err; } mutex_unlock(&ee1004_bus_lock); @@ -213,7 +243,7 @@ static int ee1004_probe(struct i2c_client *client) return 0; err_clients: - ee1004_cleanup(cnr); + ee1004_cleanup(cnr, bd); mutex_unlock(&ee1004_bus_lock); return err; @@ -221,9 +251,11 @@ static int ee1004_probe(struct i2c_client *client) static void ee1004_remove(struct i2c_client *client) { + struct ee1004_bus_data *bd = i2c_get_clientdata(client); + /* Remove page select clients if this is the last device */ mutex_lock(&ee1004_bus_lock); - ee1004_cleanup(EE1004_NUM_PAGES); + ee1004_cleanup(EE1004_NUM_PAGES, bd); mutex_unlock(&ee1004_bus_lock); }