Re: [RFC v3 PATCH v2 10/16] drm/exynos: dsi: add driver data to support Exynos5420

[Andrzej Hajda <a.hajda-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>]

On 04/27/2014 03:50 AM, YoungJun Cho wrote:
> The offset of register DSIM_PLLTMR_REG in Exynos5420 is different
> from the one in Exynos4 SoC.
> 
> In case of Exynos5420 SoC, there is no frequency band bit in DSIM_PLLCTRL_REG,
> and it uses DSIM_PHYCTRL_REG and DSIM_PHYTIMING*_REG instead.
> So this patch adds driver data to distinguish it.
> 
> Changelog v2:
> - Moves exynos_dsi_enable_clocks() after exynos_dsi_reset()
>   (commented by Andrzej Hajda)
> - Splits D-PHY control setting routines from PLL setting one
>   (commented by Andrzej Hajda)
> 
> Signed-off-by: YoungJun Cho <yj44.cho-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Acked-by: Inki Dae <inki.dae-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Acked-by: Kyungmin Park <kyungmin.park-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_dsi.c |  154 ++++++++++++++++++++++++++-----
>  1 file changed, 132 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dsi.c b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> index 4a918ec..c18dba3 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_dsi.c
> @@ -17,6 +17,7 @@
>  
>  #include <linux/clk.h>
>  #include <linux/irq.h>
> +#include <linux/of_device.h>
>  #include <linux/phy/phy.h>
>  #include <linux/regulator/consumer.h>
>  
> @@ -54,9 +55,12 @@
>  
>  /* FIFO memory AC characteristic register */
>  #define DSIM_PLLCTRL_REG	0x4c	/* PLL control register */
> -#define DSIM_PLLTMR_REG		0x50	/* PLL timer register */
>  #define DSIM_PHYACCHR_REG	0x54	/* D-PHY AC characteristic register */
>  #define DSIM_PHYACCHR1_REG	0x58	/* D-PHY AC characteristic register1 */
> +#define DSIM_PHYCTRL_REG	0x5c
> +#define DSIM_PHYTIMING_REG	0x64
> +#define DSIM_PHYTIMING1_REG	0x68
> +#define DSIM_PHYTIMING2_REG	0x6c
>  
>  /* DSIM_STATUS */
>  #define DSIM_STOP_STATE_DAT(x)		(((x) & 0xf) << 0)
> @@ -200,6 +204,21 @@
>  #define DSIM_PLL_M(x)			((x) << 4)
>  #define DSIM_PLL_S(x)			((x) << 1)
>  
> +/* DSIM_PHYTIMING */
> +#define DSIM_PHYTIMING_LPX(x)		((x) << 8)
> +#define DSIM_PHYTIMING_HS_EXIT(x)	((x) << 0)
> +
> +/* DSIM_PHYTIMING1 */
> +#define DSIM_PHYTIMING1_CLK_PREPARE(x)	((x) << 24)
> +#define DSIM_PHYTIMING1_CLK_ZERO(x)	((x) << 16)
> +#define DSIM_PHYTIMING1_CLK_POST(x)	((x) << 8)
> +#define DSIM_PHYTIMING1_CLK_TRAIL(x)	((x) << 0)
> +
> +/* DSIM_PHYTIMING2 */
> +#define DSIM_PHYTIMING2_HS_PREPARE(x)	((x) << 16)
> +#define DSIM_PHYTIMING2_HS_ZERO(x)	((x) << 8)
> +#define DSIM_PHYTIMING2_HS_TRAIL(x)	((x) << 0)
> +
>  #define DSI_MAX_BUS_WIDTH		4
>  #define DSI_NUM_VIRTUAL_CHANNELS	4
>  #define DSI_TX_FIFO_SIZE		2048
> @@ -233,6 +252,12 @@ struct exynos_dsi_transfer {
>  #define DSIM_STATE_INITIALIZED		BIT(1)
>  #define DSIM_STATE_CMD_LPM		BIT(2)
>  
> +struct exynos_dsi_driver_data {
> +	unsigned int plltmr_reg;
> +
> +	unsigned int has_freqband:1;
> +};
> +
>  struct exynos_dsi {
>  	struct mipi_dsi_host dsi_host;
>  	struct drm_connector connector;
> @@ -262,11 +287,39 @@ struct exynos_dsi {
>  
>  	spinlock_t transfer_lock; /* protects transfer_list */
>  	struct list_head transfer_list;
> +
> +	struct exynos_dsi_driver_data *driver_data;
>  };
>  
>  #define host_to_dsi(host) container_of(host, struct exynos_dsi, dsi_host)
>  #define connector_to_dsi(c) container_of(c, struct exynos_dsi, connector)
>  
> +static struct exynos_dsi_driver_data exynos4_dsi_driver_data = {
> +	.plltmr_reg = 0x50,
> +	.has_freqband = 1,
> +};
> +
> +static struct exynos_dsi_driver_data exynos5_dsi_driver_data = {
> +	.plltmr_reg = 0x58,
> +};
> +
> +static struct of_device_id exynos_dsi_of_match[] = {
> +	{ .compatible = "samsung,exynos4210-mipi-dsi",
> +	  .data = &exynos4_dsi_driver_data },
> +	{ .compatible = "samsung,exynos5420-mipi-dsi",
> +	  .data = &exynos5_dsi_driver_data },
> +	{ }
> +};

I raise again issue of compatible string.
Since exynos5410 DSIM contains DSIM_VERSION register, it is better
to use this register instead of compatible string to distinguish
device versions. So as a compatible we should use the first exynos
chipset containing this field. AFAIK it is exynos5410.
So the only thing you should do is to change compatible string from
samsung,exynos5420-mipi-dsi to samsung,exynos5410-mipi-dsi.

> 
> I posted RFC v3 without this try.
> 
> Because there is no exynos5410 relevant DTS yet,
> and making exynos5410 DTS is out of scope for this RFC.


It is irrelevant.

Regards
Andrzej


> +
> +static inline struct exynos_dsi_driver_data *exynos_dsi_get_driver_data(
> +						struct platform_device *pdev)
> +{
> +	const struct of_device_id *of_id =
> +			of_match_device(exynos_dsi_of_match, &pdev->dev);
> +
> +	return (struct exynos_dsi_driver_data *)of_id->data;
> +}
> +
>  static void exynos_dsi_wait_for_reset(struct exynos_dsi *dsi)
>  {
>  	if (wait_for_completion_timeout(&dsi->completed, msecs_to_jiffies(300)))
> @@ -340,14 +393,9 @@ static unsigned long exynos_dsi_pll_find_pms(struct exynos_dsi *dsi,
>  static unsigned long exynos_dsi_set_pll(struct exynos_dsi *dsi,
>  					unsigned long freq)
>  {
> -	static const unsigned long freq_bands[] = {
> -		100 * MHZ, 120 * MHZ, 160 * MHZ, 200 * MHZ,
> -		270 * MHZ, 320 * MHZ, 390 * MHZ, 450 * MHZ,
> -		510 * MHZ, 560 * MHZ, 640 * MHZ, 690 * MHZ,
> -		770 * MHZ, 870 * MHZ, 950 * MHZ,
> -	};
> +	struct exynos_dsi_driver_data *driver_data = dsi->driver_data;
>  	unsigned long fin, fout;
> -	int timeout, band;
> +	int timeout;
>  	u8 p, s;
>  	u16 m;
>  	u32 reg;
> @@ -368,18 +416,30 @@ static unsigned long exynos_dsi_set_pll(struct exynos_dsi *dsi,
>  			"failed to find PLL PMS for requested frequency\n");
>  		return -EFAULT;
>  	}
> +	dev_dbg(dsi->dev, "PLL freq %lu, (p %d, m %d, s %d)\n", fout, p, m, s);
>  
> -	for (band = 0; band < ARRAY_SIZE(freq_bands); ++band)
> -		if (fout < freq_bands[band])
> -			break;
> +	writel(500, dsi->reg_base + driver_data->plltmr_reg);
> +
> +	reg = DSIM_PLL_EN | DSIM_PLL_P(p) | DSIM_PLL_M(m) | DSIM_PLL_S(s);
> +
> +	if (driver_data->has_freqband) {
> +		static const unsigned long freq_bands[] = {
> +			100 * MHZ, 120 * MHZ, 160 * MHZ, 200 * MHZ,
> +			270 * MHZ, 320 * MHZ, 390 * MHZ, 450 * MHZ,
> +			510 * MHZ, 560 * MHZ, 640 * MHZ, 690 * MHZ,
> +			770 * MHZ, 870 * MHZ, 950 * MHZ,
> +		};
> +		int band;
> +
> +		for (band = 0; band < ARRAY_SIZE(freq_bands); ++band)
> +			if (fout < freq_bands[band])
> +				break;
>  
> -	dev_dbg(dsi->dev, "PLL freq %lu, (p %d, m %d, s %d), band %d\n", fout,
> -		p, m, s, band);
> +		dev_dbg(dsi->dev, "band %d\n", band);
>  
> -	writel(500, dsi->reg_base + DSIM_PLLTMR_REG);
> +		reg |= DSIM_FREQ_BAND(band);
> +	}
>  
> -	reg = DSIM_FREQ_BAND(band) | DSIM_PLL_EN
> -			| DSIM_PLL_P(p) | DSIM_PLL_M(m) | DSIM_PLL_S(s);
>  	writel(reg, dsi->reg_base + DSIM_PLLCTRL_REG);
>  
>  	timeout = 1000;
> @@ -433,6 +493,59 @@ static int exynos_dsi_enable_clock(struct exynos_dsi *dsi)
>  	return 0;
>  }
>  
> +static void exynos_dsi_set_phy_ctrl(struct exynos_dsi *dsi)
> +{
> +	struct exynos_dsi_driver_data *driver_data = dsi->driver_data;
> +	u32 reg;
> +
> +	if (driver_data->has_freqband)
> +		return;
> +
> +	/* B D-PHY */
> +	reg = 0x0af & 0x1ff;
> +	writel(reg, dsi->reg_base + DSIM_PHYCTRL_REG);
> +
> +	/*
> +	 * T LPX: Transmitted length of any Low-Power state period
> +	 * T HS-EXIT: Time that the transmitter drives LP-11 following a HS
> +	 *	burst
> +	 */
> +	reg = DSIM_PHYTIMING_LPX(0x06) | DSIM_PHYTIMING_HS_EXIT(0x0b);
> +	writel(reg, dsi->reg_base + DSIM_PHYTIMING_REG);
> +
> +	/*
> +	 * T CLK-PREPARE: Time that the transmitter drives the Clock Lane LP-00
> +	 *	Line state immediately before the HS-0 Line state starting the
> +	 *	HS transmission
> +	 * T CLK-ZERO: Time that the transmitter drives the HS-0 state prior to
> +	 *	transmitting the Clock.
> +	 * T CLK_POST: Time that the transmitter continues to send HS clock
> +	 *	after the last associated Data Lane has transitioned to LP Mode
> +	 *	Interval is defined as the period from the end of T HS-TRAIL to
> +	 *	the beginning of T CLK-TRAIL
> +	 * T CLK-TRAIL: Time that the transmitter drives the HS-0 state after
> +	 *	the last payload clock bit of a HS transmission burst
> +	 */
> +	reg = DSIM_PHYTIMING1_CLK_PREPARE(0x07) |
> +			DSIM_PHYTIMING1_CLK_ZERO(0x27) |
> +			DSIM_PHYTIMING1_CLK_POST(0x0d) |
> +			DSIM_PHYTIMING1_CLK_TRAIL(0x08);
> +	writel(reg, dsi->reg_base + DSIM_PHYTIMING1_REG);
> +
> +	/*
> +	 * T HS-PREPARE: Time that the transmitter drives the Data Lane LP-00
> +	 *	Line state immediately before the HS-0 Line state starting the
> +	 *	HS transmission
> +	 * T HS-ZERO: Time that the transmitter drives the HS-0 state prior to
> +	 *	transmitting the Sync sequence.
> +	 * T HS-TRAIL: Time that the transmitter drives the flipped differential
> +	 *	state after last payload data bit of a HS transmission burst
> +	 */
> +	reg = DSIM_PHYTIMING2_HS_PREPARE(0x09) | DSIM_PHYTIMING2_HS_ZERO(0x0d) |
> +			DSIM_PHYTIMING2_HS_TRAIL(0x0b);
> +	writel(reg, dsi->reg_base + DSIM_PHYTIMING2_REG);
> +}
> +
>  static void exynos_dsi_disable_clock(struct exynos_dsi *dsi)
>  {
>  	u32 reg;
> @@ -947,10 +1060,11 @@ static irqreturn_t exynos_dsi_irq(int irq, void *dev_id)
>  
>  static int exynos_dsi_init(struct exynos_dsi *dsi)
>  {
> -	exynos_dsi_enable_clock(dsi);
>  	exynos_dsi_reset(dsi);
>  	enable_irq(dsi->irq);
> +	exynos_dsi_enable_clock(dsi);
>  	exynos_dsi_wait_for_reset(dsi);
> +	exynos_dsi_set_phy_ctrl(dsi);
>  	exynos_dsi_init_link(dsi);
>  
>  	return 0;
> @@ -1412,6 +1526,7 @@ static int exynos_dsi_probe(struct platform_device *pdev)
>  	dsi->dsi_host.dev = &pdev->dev;
>  
>  	dsi->dev = &pdev->dev;
> +	dsi->driver_data = exynos_dsi_get_driver_data(pdev);
>  
>  	ret = exynos_dsi_parse_dt(dsi);
>  	if (ret)
> @@ -1516,11 +1631,6 @@ static const struct dev_pm_ops exynos_dsi_pm_ops = {
>  	SET_SYSTEM_SLEEP_PM_OPS(exynos_dsi_suspend, exynos_dsi_resume)
>  };
>  
> -static struct of_device_id exynos_dsi_of_match[] = {
> -	{ .compatible = "samsung,exynos4210-mipi-dsi" },
> -	{ }
> -};
> -
>  struct platform_driver dsi_driver = {
>  	.probe = exynos_dsi_probe,
>  	.remove = exynos_dsi_remove,
> 

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