diff --git a/drivers/nvmem/rockchip-otp.c b/drivers/nvmem/rockchip-otp.c index 2c0feb036f3f..f8a8c7cece98 100644 --- a/drivers/nvmem/rockchip-otp.c +++ b/drivers/nvmem/rockchip-otp.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -80,6 +81,8 @@ struct rockchip_otp { void __iomem *base; struct reset_control *rst; const struct rockchip_data *data; + /* Serializes access to the OTP controller state machine */ + struct mutex mutex; struct clk_bulk_data clks[]; }; @@ -272,10 +275,12 @@ static int rockchip_otp_read(void *context, unsigned int offset, if (!otp->data || !otp->data->reg_read) return -EINVAL; + mutex_lock(&otp->mutex); + ret = clk_bulk_prepare_enable(otp->data->num_clks, otp->clks); if (ret < 0) { dev_err(otp->dev, "failed to prepare/enable clks\n"); - return ret; + goto unlock; } offset += otp->data->read_offset; @@ -308,6 +313,9 @@ static int rockchip_otp_read(void *context, unsigned int offset, err: clk_bulk_disable_unprepare(otp->data->num_clks, otp->clks); +unlock: + mutex_unlock(&otp->mutex); + return ret; } @@ -431,6 +439,11 @@ static int rockchip_otp_probe(struct platform_device *pdev) otp->data = data; otp->dev = dev; + + ret = devm_mutex_init(dev, &otp->mutex); + if (ret) + return ret; + otp->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(otp->base)) return dev_err_probe(dev, PTR_ERR(otp->base),