From patchwork Wed Apr 5 12:56:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andy Shevchenko X-Patchwork-Id: 670646 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2741C76188 for ; Wed, 5 Apr 2023 12:56:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237330AbjDEM4w (ORCPT ); Wed, 5 Apr 2023 08:56:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34722 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237282AbjDEM4w (ORCPT ); Wed, 5 Apr 2023 08:56:52 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AC6D84EFD; Wed, 5 Apr 2023 05:56:50 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1680699410; x=1712235410; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=68RZ9c3e2hBScTlFdomwkymE5COJr2fMBuNAMNxzVxE=; b=J+F0CW5QdbmHy/uxSGA/VFxNk/GqpiLtkVjOZW81rh+IpLZ4fesGMeXC UydE7SXPWz7dQGl9DeRV6o7ltjGz2+cXVGHUZDUbBl1cjP+tcePgTLmmE aJzrjcQjixZlFWaTbcpnOLzMy7V6d4qEUF0ypWCwolMjUuXwXUlUgbtnG q5TA+ovTcAqnrCexN9Bi4oZLAwZlBH6SRYIGg++AL7zPm6LvXoC7A+cYa giNIlw/3wz62PcwQaSaUH2RdfGqhEL9zyq6K2pCO0cSkl5eGz2T3lOAYv BQa+PXD5XKGsvKpdWwXbEeD2yyLHE3+v8M+9rFjfYe4u5ZbAaM+xczMwg g==; X-IronPort-AV: E=McAfee;i="6600,9927,10670"; a="339934892" X-IronPort-AV: E=Sophos;i="5.98,319,1673942400"; d="scan'208";a="339934892" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Apr 2023 05:56:45 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10670"; a="664030654" X-IronPort-AV: E=Sophos;i="5.98,319,1673942400"; d="scan'208";a="664030654" Received: from black.fi.intel.com ([10.237.72.28]) by orsmga006.jf.intel.com with ESMTP; 05 Apr 2023 05:56:43 -0700 Received: by black.fi.intel.com (Postfix, from userid 1003) id D80351D5; Wed, 5 Apr 2023 15:56:45 +0300 (EEST) From: Andy Shevchenko To: Wolfram Sang , Khalil Blaiech , Asmaa Mnebhi , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Andy Shevchenko Subject: [PATCH v2 1/1] i2c: mlxbf: Use readl_poll_timeout_atomic() for polling Date: Wed, 5 Apr 2023 15:56:43 +0300 Message-Id: <20230405125643.42398-1-andriy.shevchenko@linux.intel.com> X-Mailer: git-send-email 2.40.0.1.gaa8946217a0b MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Convert the usage of an open-coded custom tight poll while loop with the provided readl_poll_timeout_atomic() macro. Signed-off-by: Andy Shevchenko Reviewed-by: Asmaa Mnebhi --- v2: corrected comment (Asmaa) drivers/i2c/busses/i2c-mlxbf.c | 106 ++++++++------------------------- 1 file changed, 26 insertions(+), 80 deletions(-) diff --git a/drivers/i2c/busses/i2c-mlxbf.c b/drivers/i2c/busses/i2c-mlxbf.c index 1810d5791b3d..d9d4b65cb276 100644 --- a/drivers/i2c/busses/i2c-mlxbf.c +++ b/drivers/i2c/busses/i2c-mlxbf.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include #include @@ -495,65 +496,6 @@ static u8 mlxbf_i2c_bus_count; static struct mutex mlxbf_i2c_bus_lock; -/* - * Function to poll a set of bits at a specific address; it checks whether - * the bits are equal to zero when eq_zero is set to 'true', and not equal - * to zero when eq_zero is set to 'false'. - * Note that the timeout is given in microseconds. - */ -static u32 mlxbf_i2c_poll(void __iomem *io, u32 addr, u32 mask, - bool eq_zero, u32 timeout) -{ - u32 bits; - - timeout = (timeout / MLXBF_I2C_POLL_FREQ_IN_USEC) + 1; - - do { - bits = readl(io + addr) & mask; - if (eq_zero ? bits == 0 : bits != 0) - return eq_zero ? 1 : bits; - udelay(MLXBF_I2C_POLL_FREQ_IN_USEC); - } while (timeout-- != 0); - - return 0; -} - -/* - * SW must make sure that the SMBus Master GW is idle before starting - * a transaction. Accordingly, this function polls the Master FSM stop - * bit; it returns false when the bit is asserted, true if not. - */ -static bool mlxbf_i2c_smbus_master_wait_for_idle(struct mlxbf_i2c_priv *priv) -{ - u32 mask = MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK; - u32 addr = priv->chip->smbus_master_fsm_off; - u32 timeout = MLXBF_I2C_SMBUS_TIMEOUT; - - if (mlxbf_i2c_poll(priv->mst->io, addr, mask, true, timeout)) - return true; - - return false; -} - -/* - * wait for the lock to be released before acquiring it. - */ -static bool mlxbf_i2c_smbus_master_lock(struct mlxbf_i2c_priv *priv) -{ - if (mlxbf_i2c_poll(priv->mst->io, MLXBF_I2C_SMBUS_MASTER_GW, - MLXBF_I2C_MASTER_LOCK_BIT, true, - MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT)) - return true; - - return false; -} - -static void mlxbf_i2c_smbus_master_unlock(struct mlxbf_i2c_priv *priv) -{ - /* Clear the gw to clear the lock */ - writel(0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW); -} - static bool mlxbf_i2c_smbus_transaction_success(u32 master_status, u32 cause_status) { @@ -583,6 +525,7 @@ static int mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv *priv) { u32 master_status_bits; u32 cause_status_bits; + u32 bits; /* * GW busy bit is raised by the driver and cleared by the HW @@ -591,9 +534,9 @@ static int mlxbf_i2c_smbus_check_status(struct mlxbf_i2c_priv *priv) * then read the cause and master status bits to determine if * errors occurred during the transaction. */ - mlxbf_i2c_poll(priv->mst->io, MLXBF_I2C_SMBUS_MASTER_GW, - MLXBF_I2C_MASTER_BUSY_BIT, true, - MLXBF_I2C_SMBUS_TIMEOUT); + readl_poll_timeout_atomic(priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW, + bits, !(bits & MLXBF_I2C_MASTER_BUSY_BIT), + MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT); /* Read cause status bits. */ cause_status_bits = readl(priv->mst_cause->io + @@ -740,7 +683,8 @@ mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv, u8 read_en, write_en, block_en, pec_en; u8 slave, flags, addr; u8 *read_buf; - int ret = 0; + u32 bits; + int ret; if (request->operation_cnt > MLXBF_I2C_SMBUS_MAX_OP_CNT) return -EINVAL; @@ -760,11 +704,22 @@ mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv, * Try to acquire the smbus gw lock before any reads of the GW register since * a read sets the lock. */ - if (WARN_ON(!mlxbf_i2c_smbus_master_lock(priv))) + ret = readl_poll_timeout_atomic(priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW, + bits, !(bits & MLXBF_I2C_MASTER_LOCK_BIT), + MLXBF_I2C_POLL_FREQ_IN_USEC, + MLXBF_I2C_SMBUS_LOCK_POLL_TIMEOUT); + if (WARN_ON(ret)) return -EBUSY; - /* Check whether the HW is idle */ - if (WARN_ON(!mlxbf_i2c_smbus_master_wait_for_idle(priv))) { + /* + * SW must make sure that the SMBus Master GW is idle before starting + * a transaction. Accordingly, this call polls the Master FSM stop bit; + * it returns -ETIMEDOUT when the bit is asserted, 0 if not. + */ + ret = readl_poll_timeout_atomic(priv->mst->io + priv->chip->smbus_master_fsm_off, + bits, !(bits & MLXBF_I2C_SMBUS_MASTER_FSM_STOP_MASK), + MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT); + if (WARN_ON(ret)) { ret = -EBUSY; goto out_unlock; } @@ -855,7 +810,8 @@ mlxbf_i2c_smbus_start_transaction(struct mlxbf_i2c_priv *priv, } out_unlock: - mlxbf_i2c_smbus_master_unlock(priv); + /* Clear the gw to clear the lock */ + writel(0, priv->mst->io + MLXBF_I2C_SMBUS_MASTER_GW); return ret; } @@ -1835,18 +1791,6 @@ static bool mlxbf_i2c_has_coalesce(struct mlxbf_i2c_priv *priv, bool *read, return true; } -static bool mlxbf_i2c_slave_wait_for_idle(struct mlxbf_i2c_priv *priv, - u32 timeout) -{ - u32 mask = MLXBF_I2C_CAUSE_S_GW_BUSY_FALL; - u32 addr = MLXBF_I2C_CAUSE_ARBITER; - - if (mlxbf_i2c_poll(priv->slv_cause->io, addr, mask, false, timeout)) - return true; - - return false; -} - static struct i2c_client *mlxbf_i2c_get_slave_from_addr( struct mlxbf_i2c_priv *priv, u8 addr) { @@ -1949,7 +1893,9 @@ static int mlxbf_i2c_irq_send(struct mlxbf_i2c_priv *priv, u8 recv_bytes) * Wait until the transfer is completed; the driver will wait * until the GW is idle, a cause will rise on fall of GW busy. */ - mlxbf_i2c_slave_wait_for_idle(priv, MLXBF_I2C_SMBUS_TIMEOUT); + readl_poll_timeout_atomic(priv->slv_cause->io + MLXBF_I2C_CAUSE_ARBITER, + data32, data32 & MLXBF_I2C_CAUSE_S_GW_BUSY_FALL, + MLXBF_I2C_POLL_FREQ_IN_USEC, MLXBF_I2C_SMBUS_TIMEOUT); clear_csr: /* Release the Slave GW. */