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Mon, 22 Jul 2013 14:15:21 +0200 (CEST) From: Gerhard Sittig To: linuxppc-dev@lists.ozlabs.org, Anatolij Gustschin , Mike Turquette , linux-arm-kernel@lists.infradead.org, devicetree-discuss@lists.ozlabs.org Subject: [PATCH v3 01/31] spi: mpc512x: cleanup clock API use Date: Mon, 22 Jul 2013 14:14:28 +0200 Message-Id: <1374495298-22019-2-git-send-email-gsi@denx.de> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1374495298-22019-1-git-send-email-gsi@denx.de> References: <1374166855-7280-1-git-send-email-gsi@denx.de> <1374495298-22019-1-git-send-email-gsi@denx.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130722_081557_075350_0574F6D4 X-CRM114-Status: GOOD ( 14.19 ) X-Spam-Score: -1.9 (-) Cc: Detlev Zundel , Wolfram Sang , Greg Kroah-Hartman , Gerhard Sittig , Rob Herring , Mark Brown , Marc Kleine-Budde , Pantelis Antoniou , David Woodhouse , Wolfgang Grandegger , Mauro Carvalho Chehab X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP cleanup the MPC512x SoC's SPI master's use of the clock API - get, prepare, and enable the MCLK during probe; disable, unprepare and put the MCLK upon remove; hold a reference to the clock over the period of use - fetch MCLK rate (reference) once during probe and slightly reword BCLK (bitrate) determination to reduce redundancy as well as to not exceed the maximum text line length - stick with the PPC_CLOCK 'psc%d_mclk' name for clock lookup, only switch to a fixed string later after device tree based clock lookup will have become available Signed-off-by: Gerhard Sittig --- drivers/spi/spi-mpc512x-psc.c | 52 +++++++++++++++++++++++++++-------------- 1 file changed, 34 insertions(+), 18 deletions(-) diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c index 29fce6a..823e5e0 100644 --- a/drivers/spi/spi-mpc512x-psc.c +++ b/drivers/spi/spi-mpc512x-psc.c @@ -38,7 +38,8 @@ struct mpc512x_psc_spi { struct mpc512x_psc_fifo __iomem *fifo; unsigned int irq; u8 bits_per_word; - u32 mclk; + struct clk *clk_mclk; + u32 mclk_rate; struct completion txisrdone; }; @@ -72,6 +73,7 @@ static void mpc512x_psc_spi_activate_cs(struct spi_device *spi) struct mpc52xx_psc __iomem *psc = mps->psc; u32 sicr; u32 ccr; + int speed; u16 bclkdiv; sicr = in_be32(&psc->sicr); @@ -95,10 +97,10 @@ static void mpc512x_psc_spi_activate_cs(struct spi_device *spi) ccr = in_be32(&psc->ccr); ccr &= 0xFF000000; - if (cs->speed_hz) - bclkdiv = (mps->mclk / cs->speed_hz) - 1; - else - bclkdiv = (mps->mclk / 1000000) - 1; /* default 1MHz */ + speed = cs->speed_hz; + if (!speed) + speed = 1000000; /* default 1MHz */ + bclkdiv = (mps->mclk_rate / speed) - 1; ccr |= (((bclkdiv & 0xff) << 16) | (((bclkdiv >> 8) & 0xff) << 8)); out_be32(&psc->ccr, ccr); @@ -386,19 +388,11 @@ static int mpc512x_psc_spi_port_config(struct spi_master *master, { struct mpc52xx_psc __iomem *psc = mps->psc; struct mpc512x_psc_fifo __iomem *fifo = mps->fifo; - struct clk *spiclk; - int ret = 0; - char name[32]; u32 sicr; u32 ccr; + int speed; u16 bclkdiv; - sprintf(name, "psc%d_mclk", master->bus_num); - spiclk = clk_get(&master->dev, name); - clk_enable(spiclk); - mps->mclk = clk_get_rate(spiclk); - clk_put(spiclk); - /* Reset the PSC into a known state */ out_8(&psc->command, MPC52xx_PSC_RST_RX); out_8(&psc->command, MPC52xx_PSC_RST_TX); @@ -425,7 +419,8 @@ static int mpc512x_psc_spi_port_config(struct spi_master *master, ccr = in_be32(&psc->ccr); ccr &= 0xFF000000; - bclkdiv = (mps->mclk / 1000000) - 1; /* default 1MHz */ + speed = 1000000; /* default 1MHz */ + bclkdiv = (mps->mclk_rate / speed) - 1; ccr |= (((bclkdiv & 0xff) << 16) | (((bclkdiv >> 8) & 0xff) << 8)); out_be32(&psc->ccr, ccr); @@ -445,7 +440,7 @@ static int mpc512x_psc_spi_port_config(struct spi_master *master, mps->bits_per_word = 8; - return ret; + return 0; } static irqreturn_t mpc512x_psc_spi_isr(int irq, void *dev_id) @@ -479,6 +474,9 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr, struct spi_master *master; int ret; void *tempp; + int psc_num; + char clk_name[16]; + struct clk *clk; master = spi_alloc_master(dev, sizeof *mps); if (master == NULL) @@ -521,16 +519,32 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr, goto free_master; init_completion(&mps->txisrdone); + psc_num = master->bus_num; + snprintf(clk_name, sizeof(clk_name), "psc%d_mclk", psc_num); + clk = devm_clk_get(dev, clk_name); + if (IS_ERR(clk)) + goto free_irq; + ret = clk_prepare_enable(clk); + if (ret) { + devm_clk_put(dev, clk); + goto free_irq; + } + mps->clk_mclk = clk; + mps->mclk_rate = clk_get_rate(clk); + ret = mpc512x_psc_spi_port_config(master, mps); if (ret < 0) - goto free_irq; + goto free_clock; ret = spi_register_master(master); if (ret < 0) - goto free_irq; + goto free_clock; return ret; +free_clock: + clk_disable_unprepare(mps->clk_mclk); + devm_clk_put(dev, mps->clk_mclk); free_irq: free_irq(mps->irq, mps); free_master: @@ -547,6 +561,8 @@ static int mpc512x_psc_spi_do_remove(struct device *dev) struct mpc512x_psc_spi *mps = spi_master_get_devdata(master); spi_unregister_master(master); + clk_disable_unprepare(mps->clk_mclk); + devm_clk_put(dev, mps->clk_mclk); free_irq(mps->irq, mps); if (mps->psc) iounmap(mps->psc);