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Commit a81a5094 authored by Gerhard Sittig's avatar Gerhard Sittig Committed by Mark Brown
Browse files

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: default avatarGerhard Sittig <gsi@denx.de>
Signed-off-by: default avatarMark Brown <broonie@linaro.org>
parent b36f4be3

drivers/spi/spi-mpc512x-psc.c

+30 −18
Original line number Diff line number Diff line
@@ -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);