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 <g...@denx.de>
---
drivers/spi/spi-mpc512x-psc.c | 48 +++++++++++++++++++++++++----------------
1 file changed, 30 insertions(+), 18 deletions(-)
diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c
index 29fce6a..85581f3 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);
--
1.7.10.4
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