[PATCH V2] Use clock freqency from the device tree to calculate correct MPC5200 PSC clock.
Wolfram Sang
w.sang at pengutronix.de
Sat Aug 8 20:26:13 EST 2009
On Fri, Aug 07, 2009 at 03:19:36PM -0400, Jon Smirl wrote:
> Use clock freqency from the device tree to calculate correct MPC5200 PSC clock.
> Previous code had errors or used a constant. This versions computes
> the right clock based on the xtal and register settings.
>
> Signed-off-by: Jon Smirl <jonsmirl at gmail.com>
Acked-by: Wolfram Sang <w.sang at pengutronix.de>
> ---
> arch/powerpc/include/asm/mpc52xx.h | 2 +-
> arch/powerpc/platforms/52xx/mpc52xx_common.c | 26 ++++++++++++++++++++++++--
> drivers/spi/mpc52xx_psc_spi.c | 8 +-------
> sound/soc/fsl/mpc5200_psc_i2s.c | 11 +----------
> 4 files changed, 27 insertions(+), 20 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/mpc52xx.h b/arch/powerpc/include/asm/mpc52xx.h
> index cadd398..1ca8a0e 100644
> --- a/arch/powerpc/include/asm/mpc52xx.h
> +++ b/arch/powerpc/include/asm/mpc52xx.h
> @@ -285,7 +285,7 @@ struct mpc52xx_rtc {
> extern void mpc5200_setup_xlb_arbiter(void);
> extern void mpc52xx_declare_of_platform_devices(void);
> extern void mpc52xx_map_common_devices(void);
> -extern int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv);
> +extern int mpc52xx_set_psc_clkdiv(int psc_id, int freq);
> extern unsigned int mpc52xx_get_xtal_freq(struct device_node *node);
> extern void mpc52xx_restart(char *cmd);
>
> diff --git a/arch/powerpc/platforms/52xx/mpc52xx_common.c b/arch/powerpc/platforms/52xx/mpc52xx_common.c
> index a46bad0..8a19156 100644
> --- a/arch/powerpc/platforms/52xx/mpc52xx_common.c
> +++ b/arch/powerpc/platforms/52xx/mpc52xx_common.c
> @@ -110,6 +110,8 @@ static struct of_device_id mpc52xx_cdm_ids[] __initdata = {
> {}
> };
>
> +static u32 mpc52xx_fsystem; /* fsystem clock on mpc5200 */
> +
> /**
> * mpc52xx_map_common_devices: iomap devices required by common code
> */
> @@ -117,6 +119,7 @@ void __init
> mpc52xx_map_common_devices(void)
> {
> struct device_node *np;
> + u32 val;
>
> /* mpc52xx_wdt is mapped here and used in mpc52xx_restart,
> * possibly from a interrupt context. wdt is only implement
> @@ -133,8 +136,16 @@ mpc52xx_map_common_devices(void)
>
> /* Clock Distribution Module, used by PSC clock setting function */
> np = of_find_matching_node(NULL, mpc52xx_cdm_ids);
> + mpc52xx_fsystem = mpc5xxx_get_bus_frequency(np);
> mpc52xx_cdm = of_iomap(np, 0);
> of_node_put(np);
> +
> + /* compute fsystem, it is either 4 or 8 times the bus freq */
> + val = in_be32(&mpc52xx_cdm->rstcfg);
> + if (val & (1 << 5))
> + mpc52xx_fsystem *= 8;
> + else
> + mpc52xx_fsystem *= 4;
> }
>
> /**
> @@ -143,17 +154,28 @@ mpc52xx_map_common_devices(void)
> * @psc_id: id of psc port; must be 1,2,3 or 6
> * @clkdiv: clock divider value to put into CDM PSC register.
> */
> -int mpc52xx_set_psc_clkdiv(int psc_id, int clkdiv)
> +int mpc52xx_set_psc_clkdiv(int psc_id, int freq)
> {
> unsigned long flags;
> u16 __iomem *reg;
> u32 val;
> - u32 mask;
> + u32 mask, clkdiv, err;
> u32 mclken_div;
>
> if (!mpc52xx_cdm)
> return -ENODEV;
>
> + /* figure out the closest frequency the hardware can make */
> + clkdiv = mpc52xx_fsystem / freq;
> + err = mpc52xx_fsystem % freq;
> + if (err > freq / 2)
> + clkdiv++;
> + /* hardware is not very flexible, there will be significant error */
> + /* frequency error = fsystem / clkdiv - freq; */
> +
> + /* hardware adds one to the divisor */
> + clkdiv -= 1;
> +
> mclken_div = 0x8000 | (clkdiv & 0x1FF);
> switch (psc_id) {
> case 1: reg = &mpc52xx_cdm->mclken_div_psc1; mask = 0x20; break;
> diff --git a/drivers/spi/mpc52xx_psc_spi.c b/drivers/spi/mpc52xx_psc_spi.c
> index d2a04d6..5c8e621 100644
> --- a/drivers/spi/mpc52xx_psc_spi.c
> +++ b/drivers/spi/mpc52xx_psc_spi.c
> @@ -33,7 +33,6 @@
> struct mpc52xx_psc_spi {
> /* fsl_spi_platform data */
> void (*cs_control)(struct spi_device *spi, bool on);
> - u32 sysclk;
>
> /* driver internal data */
> struct mpc52xx_psc __iomem *psc;
> @@ -313,12 +312,9 @@ static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps)
> {
> struct mpc52xx_psc __iomem *psc = mps->psc;
> struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo;
> - u32 mclken_div;
> int ret = 0;
>
> - /* default sysclk is 512MHz */
> - mclken_div = (mps->sysclk ? mps->sysclk : 512000000) / MCLK;
> - mpc52xx_set_psc_clkdiv(psc_id, mclken_div);
> + mpc52xx_set_psc_clkdiv(psc_id, MCLK);
>
> /* Reset the PSC into a known state */
> out_8(&psc->command, MPC52xx_PSC_RST_RX);
> @@ -383,12 +379,10 @@ static int __init mpc52xx_psc_spi_do_probe(struct of_device *op, u32 regaddr,
> dev_warn(&op->dev, "probe called without platform data, no "
> "cs_control function will be called\n");
> mps->cs_control = NULL;
> - mps->sysclk = 0;
> master->bus_num = bus_num;
> master->num_chipselect = 255;
> } else {
> mps->cs_control = pdata->cs_control;
> - mps->sysclk = pdata->sysclk;
> master->bus_num = pdata->bus_num;
> master->num_chipselect = pdata->max_chipselect;
> }
> diff --git a/sound/soc/fsl/mpc5200_psc_i2s.c b/sound/soc/fsl/mpc5200_psc_i2s.c
> index c58fcde..8de4719 100644
> --- a/sound/soc/fsl/mpc5200_psc_i2s.c
> +++ b/sound/soc/fsl/mpc5200_psc_i2s.c
> @@ -115,7 +115,6 @@ static int psc_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
> int clk_id, unsigned int freq, int dir)
> {
> struct psc_dma *psc_dma = cpu_dai->private_data;
> - int clkdiv, err;
>
> dev_dbg(psc_dma->dev, "psc_i2s_set_sysclk(cpu_dai=%p, freq=%u, dir=%i)\n",
> cpu_dai, freq, dir);
> @@ -128,15 +127,7 @@ static int psc_i2s_set_sysclk(struct snd_soc_dai *cpu_dai,
> psc_dma->sicr &= ~MPC52xx_PSC_SICR_CELLSLAVE;
> psc_dma->sicr |= MPC52xx_PSC_SICR_GENCLK;
>
> - clkdiv = ppc_proc_freq / freq;
> - err = ppc_proc_freq % freq;
> - if (err > freq / 2)
> - clkdiv++;
> -
> - dev_dbg(psc_dma->dev, "psc_i2s_set_sysclk(clkdiv %d freq error=%ldHz)\n",
> - clkdiv, (ppc_proc_freq / clkdiv - freq));
> -
> - return mpc52xx_set_psc_clkdiv(psc_dma->id + 1, clkdiv);
> + return mpc52xx_set_psc_clkdiv(psc_dma->id + 1, freq);
> }
> }
> return 0;
>
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--
Pengutronix e.K. | Wolfram Sang |
Industrial Linux Solutions | http://www.pengutronix.de/ |
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