From patchwork Thu Jun 28 12:48:34 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ramalingam C X-Patchwork-Id: 10493805 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DE9216022E for ; Thu, 28 Jun 2018 12:57:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CAB1329EA5 for ; Thu, 28 Jun 2018 12:57:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BE1FF29EB7; Thu, 28 Jun 2018 12:57:48 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4B8BD29EA5 for ; Thu, 28 Jun 2018 12:57:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 9469A6ED43; Thu, 28 Jun 2018 12:57:47 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3B1876ED40 for ; Thu, 28 Jun 2018 12:57:43 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 28 Jun 2018 05:57:43 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.51,283,1526367600"; d="scan'208";a="51210088" Received: from mint-dev.iind.intel.com ([10.223.25.164]) by fmsmga008.fm.intel.com with ESMTP; 28 Jun 2018 05:57:41 -0700 From: Ramalingam C To: jani.nikula@intel.com, intel-gfx@lists.freedesktop.org, ville.syrjala@linux.intel.com Date: Thu, 28 Jun 2018 18:18:34 +0530 Message-Id: <1530190114-4349-2-git-send-email-ramalingam.c@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1530190114-4349-1-git-send-email-ramalingam.c@intel.com> References: <1530190114-4349-1-git-send-email-ramalingam.c@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v6 2/2] drm/i915/gmbus: Enable burst read X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: rodrigo.vivi@intel.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Support for Burst read in HW is added for HDCP2.2 compliance requirement. This patch enables the burst read for all the gmbus read of more than 511Bytes, on capable platforms. v2: Extra line is removed. v3: Macro is added for detecting the BURST_READ Support [Jani] Runtime detection of the need for burst_read [Jani] Calculation enhancement. v4: GMBUS0 reg val is passed from caller [ville] Removed a extra var [ville] Extra brackets are removed [ville] Implemented the handling of 512Bytes Burst Read. v5: Burst read max length is fixed at 767Bytes [Ville] v6: Collecting the received reviewed-by. Signed-off-by: Ramalingam C Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/i915_drv.h | 3 ++ drivers/gpu/drm/i915/i915_reg.h | 1 + drivers/gpu/drm/i915/intel_i2c.c | 61 +++++++++++++++++++++++++++++++++------- 3 files changed, 55 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 2b684f431c60..7636afd78368 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2574,6 +2574,9 @@ intel_info(const struct drm_i915_private *dev_priv) IS_SKL_GT3(dev_priv) || IS_SKL_GT4(dev_priv)) #define HAS_GMBUS_IRQ(dev_priv) (INTEL_GEN(dev_priv) >= 4) +#define HAS_GMBUS_BURST_READ(dev_priv) (INTEL_GEN(dev_priv) >= 10 || \ + IS_GEMINILAKE(dev_priv) || \ + IS_KABYLAKE(dev_priv)) /* With the 945 and later, Y tiling got adjusted so that it was 32 128-byte * rows, which changed the alignment requirements and fence programming. diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 7353ad447936..7bfc11a676b1 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -3064,6 +3064,7 @@ enum i915_power_well_id { #define GMBUS_RATE_400KHZ (2 << 8) /* reserved on Pineview */ #define GMBUS_RATE_1MHZ (3 << 8) /* reserved on Pineview */ #define GMBUS_HOLD_EXT (1 << 7) /* 300ns hold time, rsvd on Pineview */ +#define GMBUS_BYTE_CNT_OVERRIDE (1 << 6) #define GMBUS_PIN_DISABLED 0 #define GMBUS_PIN_SSC 1 #define GMBUS_PIN_VGADDC 2 diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c index 82bb9c33ab1c..bef32b7c248e 100644 --- a/drivers/gpu/drm/i915/intel_i2c.c +++ b/drivers/gpu/drm/i915/intel_i2c.c @@ -371,12 +371,29 @@ unsigned int gmbus_max_xfer_size(struct drm_i915_private *dev_priv) static int gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv, unsigned short addr, u8 *buf, unsigned int len, - u32 gmbus1_index) + u32 gmbus0_reg, u32 gmbus1_index) { + unsigned int size = len; + bool burst_read = len > gmbus_max_xfer_size(dev_priv); + bool extra_byte_added = false; + + if (burst_read) { + /* + * As per HW Spec, for 512Bytes need to read extra Byte and + * Ignore the extra byte read. + */ + if (len == 512) { + extra_byte_added = true; + len++; + } + size = len % 256 + 256; + I915_WRITE_FW(GMBUS0, gmbus0_reg | GMBUS_BYTE_CNT_OVERRIDE); + } + I915_WRITE_FW(GMBUS1, gmbus1_index | GMBUS_CYCLE_WAIT | - (len << GMBUS_BYTE_COUNT_SHIFT) | + (size << GMBUS_BYTE_COUNT_SHIFT) | (addr << GMBUS_SLAVE_ADDR_SHIFT) | GMBUS_SLAVE_READ | GMBUS_SW_RDY); while (len) { @@ -389,17 +406,34 @@ gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv, val = I915_READ_FW(GMBUS3); do { + if (extra_byte_added && len == 1) + break; + *buf++ = val & 0xff; val >>= 8; } while (--len && ++loop < 4); + + if (burst_read && len == size - 4) + /* Reset the override bit */ + I915_WRITE_FW(GMBUS0, gmbus0_reg); } return 0; } +/* + * HW spec says that 512Bytes in Burst read need special treatment. + * But it doesn't talk about other multiple of 256Bytes. And couldn't locate + * an I2C slave, which supports such a lengthy burst read too for experiments. + * + * So until things get clarified on HW support, to avoid the burst read length + * in fold of 256Bytes except 512, max burst read length is fixed at 767Bytes. + */ +#define INTEL_GMBUS_BURST_READ_MAX_LEN 767U + static int gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg, - u32 gmbus1_index) + u32 gmbus0_reg, u32 gmbus1_index) { u8 *buf = msg->buf; unsigned int rx_size = msg->len; @@ -407,10 +441,13 @@ gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg, int ret; do { - len = min(rx_size, gmbus_max_xfer_size(dev_priv)); + if (HAS_GMBUS_BURST_READ(dev_priv)) + len = min(rx_size, INTEL_GMBUS_BURST_READ_MAX_LEN); + else + len = min(rx_size, gmbus_max_xfer_size(dev_priv)); - ret = gmbus_xfer_read_chunk(dev_priv, msg->addr, - buf, len, gmbus1_index); + ret = gmbus_xfer_read_chunk(dev_priv, msg->addr, buf, len, + gmbus0_reg, gmbus1_index); if (ret) return ret; @@ -498,7 +535,8 @@ gmbus_is_index_xfer(struct i2c_msg *msgs, int i, int num) } static int -gmbus_index_xfer(struct drm_i915_private *dev_priv, struct i2c_msg *msgs) +gmbus_index_xfer(struct drm_i915_private *dev_priv, struct i2c_msg *msgs, + u32 gmbus0_reg) { u32 gmbus1_index = 0; u32 gmbus5 = 0; @@ -516,7 +554,8 @@ gmbus_index_xfer(struct drm_i915_private *dev_priv, struct i2c_msg *msgs) I915_WRITE_FW(GMBUS5, gmbus5); if (msgs[1].flags & I2C_M_RD) - ret = gmbus_xfer_read(dev_priv, &msgs[1], gmbus1_index); + ret = gmbus_xfer_read(dev_priv, &msgs[1], gmbus0_reg, + gmbus1_index); else ret = gmbus_xfer_write(dev_priv, &msgs[1], gmbus1_index); @@ -551,10 +590,12 @@ do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num, for (; i < num; i += inc) { inc = 1; if (gmbus_is_index_xfer(msgs, i, num)) { - ret = gmbus_index_xfer(dev_priv, &msgs[i]); + ret = gmbus_index_xfer(dev_priv, &msgs[i], + gmbus0_source | bus->reg0); inc = 2; /* an index transmission is two msgs */ } else if (msgs[i].flags & I2C_M_RD) { - ret = gmbus_xfer_read(dev_priv, &msgs[i], 0); + ret = gmbus_xfer_read(dev_priv, &msgs[i], + gmbus0_source | bus->reg0, 0); } else { ret = gmbus_xfer_write(dev_priv, &msgs[i], 0); }