From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757857AbbLBK16 (ORCPT ); Wed, 2 Dec 2015 05:27:58 -0500 Received: from mail-wm0-f54.google.com ([74.125.82.54]:34719 "EHLO mail-wm0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752250AbbLBKZi (ORCPT ); Wed, 2 Dec 2015 05:25:38 -0500 From: Bartosz Golaszewski To: Wolfram Sang Cc: linux-i2c , LKML , Bartosz Golaszewski Subject: [RESEND PATCH v2 3/9] eeprom: at24: tie up an additional address for at24cs series Date: Wed, 2 Dec 2015 11:25:20 +0100 Message-Id: <1449051926-21918-4-git-send-email-bgolaszewski@baylibre.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1449051926-21918-1-git-send-email-bgolaszewski@baylibre.com> References: <1449051926-21918-1-git-send-email-bgolaszewski@baylibre.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The at24cs series EEPROM chips have an additional read-only memory area, that is visible on a different i2c slave address. Tie it up with a dummy device. Signed-off-by: Bartosz Golaszewski --- drivers/misc/eeprom/at24.c | 30 ++++++++++++++++++++++++++---- 1 file changed, 26 insertions(+), 4 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 5d7c090..08cc327 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -103,6 +103,8 @@ MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)"); #define AT24_BITMASK(x) (BIT(x) - 1) +#define AT24CS_SERIAL_ADDR(addr) (addr + 0x08) + /* create non-zero magic value for given eeprom parameters */ #define AT24_DEVICE_MAGIC(_len, _flags) \ ((1 << AT24_SIZE_FLAGS | (_flags)) \ @@ -558,6 +560,8 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) if (chip.flags & AT24_FLAG_TAKE8ADDR) num_addresses = 8; + else if (chip.flags & AT24_FLAG_SERIAL) + num_addresses = 2; else num_addresses = DIV_ROUND_UP(chip.byte_len, (chip.flags & AT24_FLAG_ADDR16) ? 65536 : 256); @@ -616,12 +620,30 @@ static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) at24->client[0] = client; /* use dummy devices for multiple-address chips */ - for (i = 1; i < num_addresses; i++) { - at24->client[i] = i2c_new_dummy(client->adapter, + if (at24->chip.flags & AT24_FLAG_TAKE8ADDR) { + for (i = 1; i < num_addresses; i++) { + at24->client[i] = i2c_new_dummy(client->adapter, + client->addr + i); + if (!at24->client[i]) { + dev_err(&client->dev, + "address 0x%02x unavailable\n", client->addr + i); - if (!at24->client[i]) { + err = -EADDRINUSE; + goto err_clients; + } + } + } + + /* + * at24cs series tie up an additional address for the memory area + * contining the serial number + */ + if (at24->chip.flags & AT24_FLAG_SERIAL) { + at24->client[1] = i2c_new_dummy(client->adapter, + AT24CS_SERIAL_ADDR(client->addr)); + if (!at24->client[1]) { dev_err(&client->dev, "address 0x%02x unavailable\n", - client->addr + i); + AT24CS_SERIAL_ADDR(client->addr)); err = -EADDRINUSE; goto err_clients; } -- 2.1.4