From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Sf9z6-0003ld-PL for barebox@lists.infradead.org; Thu, 14 Jun 2012 13:21:16 +0000 From: Wolfram Sang Date: Thu, 14 Jun 2012 15:21:05 +0200 Message-Id: <1339680065-12169-9-git-send-email-w.sang@pengutronix.de> In-Reply-To: <1339680065-12169-1-git-send-email-w.sang@pengutronix.de> References: <1339680065-12169-1-git-send-email-w.sang@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: [PATCH V2 8/8] arm: mxs: add write support for ocotp To: barebox@lists.infradead.org Cc: Wolfram Sang Since we now can change HCLK and VDDIO, we can now support writing to OCOTP. Writing is done via a special data register. This is u32, so we need to fill a temporary buffer when offset or count is not aligned. The write is also protected by a special device variable. Signed-off-by: Wolfram Sang --- arch/arm/mach-mxs/Kconfig | 11 +++++ arch/arm/mach-mxs/ocotp.c | 109 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 120 insertions(+) diff --git a/arch/arm/mach-mxs/Kconfig b/arch/arm/mach-mxs/Kconfig index 57bd556..9ce7c7a 100644 --- a/arch/arm/mach-mxs/Kconfig +++ b/arch/arm/mach-mxs/Kconfig @@ -81,6 +81,17 @@ config MXS_OCOTP internal view). Don't use register offsets here, the SET, CLR and TGL registers are not mapped! +config MXS_OCOTP_WRITABLE + bool "OCOTP write support" + depends on MXS_OCOTP + help + Enable this option to add writing to OCOTP. + Warning: blown bits can not be unblown. Use with care. + + Before being actually able to blow the bits, you need to explicitely + enable writing: + ocotp0.permanent_write_enable=1 + endmenu menu "Board specific settings " diff --git a/arch/arm/mach-mxs/ocotp.c b/arch/arm/mach-mxs/ocotp.c index f18d066..92a287f 100644 --- a/arch/arm/mach-mxs/ocotp.c +++ b/arch/arm/mach-mxs/ocotp.c @@ -25,13 +25,19 @@ #include #include #include +#include +#include #define DRIVERNAME "ocotp" #define OCOTP_CTRL 0x0 +# define OCOTP_CTRL_ADDR_MASK 0x3f # define OCOTP_CTRL_BUSY (1 << 8) # define OCOTP_CTRL_ERROR (1 << 9) # define OCOTP_CTRL_RD_BANK_OPEN (1 << 12) +# define OCOTP_CTRL_WR_UNLOCK 0x3e770000 + +#define OCOTP_DATA 0x10 #define OCOTP_WORD_OFFSET 0x20 @@ -92,11 +98,102 @@ static ssize_t mxs_ocotp_cdev_read(struct cdev *cdev, void *buf, size_t count, return size; } +static ssize_t mxs_ocotp_cdev_write(struct cdev *cdev, const void *buf, size_t count, + ulong offset, ulong flags) +{ + struct ocotp_priv *priv = cdev->priv; + void __iomem *base = priv->base; + const char *write_param; + unsigned int write_enabled = 0; + unsigned long old_hclk, aligned_offset; + int old_vddio, num_words, num_bytes, i, ret = 0; + u8 *work_buf; + u32 reg; + + write_param = dev_get_param(cdev->dev, "permanent_write_enable"); + if (write_param) + write_enabled = simple_strtoul(write_param, NULL, 0); + + if (!write_param || !write_enabled) + return -EPERM; + + /* we can only work on u32, so calc some helpers */ + aligned_offset = offset & ~3UL; + num_words = DIV_ROUND_UP(offset - aligned_offset + count, 4); + num_bytes = num_words << 2; + + /* read in all words which will be modified */ + work_buf = xmalloc(num_bytes); + + i = mxs_ocotp_cdev_read(cdev, work_buf, num_bytes, aligned_offset, 0); + if (i != num_bytes) { + ret = -ENXIO; + goto free_mem; + } + + /* modify read words with to be written data */ + for (i = 0; i < count; i++) + work_buf[offset - aligned_offset + i] |= ((u8 *)buf)[i]; + + /* prepare system for OTP write */ + old_hclk = imx_get_hclk(); + old_vddio = imx_get_vddio(); + + imx_set_hclk(24000000); + imx_set_vddio(2800000); + + writel(OCOTP_CTRL_RD_BANK_OPEN, base + OCOTP_CTRL + BIT_CLR); + + if (mxs_ocotp_wait_busy(priv)) { + ret = -ETIMEDOUT; + goto restore_system; + } + + /* write word for word via data register */ + for (i = 0; i < num_words; i++) { + reg = readl(base + OCOTP_CTRL) & ~OCOTP_CTRL_ADDR_MASK; + reg |= OCOTP_CTRL_WR_UNLOCK | ((aligned_offset >> 2) + i); + writel(reg, base + OCOTP_CTRL); + + writel(((u32 *)work_buf)[i], base + OCOTP_DATA); + + if (mxs_ocotp_wait_busy(priv)) { + ret = -ETIMEDOUT; + goto restore_system; + } + + mdelay(2); + } + +restore_system: + imx_set_vddio(old_vddio); + imx_set_hclk(old_hclk); +free_mem: + free(work_buf); + + return ret; +} + static struct file_operations mxs_ocotp_ops = { .read = mxs_ocotp_cdev_read, .lseek = dev_lseek_default, }; +static int mxs_ocotp_write_enable_set(struct device_d *dev, struct param_d *param, + const char *val) +{ + unsigned long write_enable; + + if (!val) + return -EINVAL; + + write_enable = simple_strtoul(val, NULL, 0); + if (write_enable > 1) + return -EINVAL; + + return dev_param_set_generic(dev, param, write_enable ? "1" : "0"); +} + static int mxs_ocotp_probe(struct device_d *dev) { int err; @@ -113,6 +210,18 @@ static int mxs_ocotp_probe(struct device_d *dev) if (err < 0) return err; + if (IS_ENABLED(CONFIG_MXS_OCOTP_WRITABLE)) { + mxs_ocotp_ops.write = mxs_ocotp_cdev_write; + + err = dev_add_param(dev, "permanent_write_enable", + mxs_ocotp_write_enable_set, NULL, 0); + if (err < 0) + return err; + err = dev_set_param(dev, "permanent_write_enable", "0"); + if (err < 0) + return err; + } + return 0; } -- 1.7.10 _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox