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author | 2013-08-06 22:43:41 +0200 | |
---|---|---|
committer | 2013-08-22 11:02:07 +0100 | |
commit | a81a5094a3287120cac148de4c9bdb2e53e5bfae (patch) | |
tree | 110f19076264a98ba13584519810c499fd8942be /drivers/spi/spi-mpc512x-psc.c | |
parent | Linux 3.11-rc6 (diff) | |
download | linux-a81a5094a3287120cac148de4c9bdb2e53e5bfae.tar.gz linux-a81a5094a3287120cac148de4c9bdb2e53e5bfae.tar.bz2 linux-a81a5094a3287120cac148de4c9bdb2e53e5bfae.zip |
spi: mpc512x: cleanup clock API use
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 <gsi@denx.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'drivers/spi/spi-mpc512x-psc.c')
-rw-r--r-- | drivers/spi/spi-mpc512x-psc.c | 48 |
1 files changed, 30 insertions, 18 deletions
diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c index 29fce6af5145..85581f307945 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 +519,29 @@ 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) + 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); free_irq: free_irq(mps->irq, mps); free_master: @@ -547,6 +558,7 @@ 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); free_irq(mps->irq, mps); if (mps->psc) iounmap(mps->psc); |