Re: [RFC PATCH 2/3] ARM: vexpress: Add device tree support for CLCD driver

[Pawel Moll <pawel.moll@arm.com>]

On Wed, 2012-09-19 at 17:04 +0100, Ryan Harkin wrote:
> Add support for device tree in the amba-clcd PL111 video driver.
> 
> Special case support is added for the A9 CoreTile which uses the "legacy"
> address map and has a PL111 device on-board.  The default case is to configure
> the device on the motherboard.
> 
> Oscillator support is added for the A9 CoreTile's CLCD driver.
> 
> Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
> ---
>  arch/arm/mach-vexpress/v2m.c |   58 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
> 
> diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
> index 37608f2..799e00e 100644
> --- a/arch/arm/mach-vexpress/v2m.c
> +++ b/arch/arm/mach-vexpress/v2m.c
> @@ -3,6 +3,7 @@
>   */
>  #include <linux/device.h>
>  #include <linux/amba/bus.h>
> +#include <linux/amba/clcd.h>
>  #include <linux/amba/mmci.h>
>  #include <linux/io.h>
>  #include <linux/init.h>
> @@ -37,6 +38,7 @@
>  #include <mach/ct-ca9x4.h>
>  #include <mach/motherboard.h>
>  
> +#include <plat/clcd.h>
>  #include <plat/sched_clock.h>
>  
>  #include "core.h"
> @@ -541,6 +543,54 @@ MACHINE_END
>  
>  #if defined(CONFIG_ARCH_VEXPRESS_DT)
>  
> +static struct v2m_osc v2m_dt_clcd_osc = {
> +	.rate_min = 10000000,
> +	.rate_max = 165000000,
> +	.rate_default = 23750000,
> +};
> +
> +static int v2m_dt_clcd_init(void)
> +{
> +	struct device_node *node;
> +	u32 osc;
> +	u32 clcd_site;
> +	u32 dvimode;
> +	const __be32 *prop;
> +	int len, na, ns;
> +	phys_addr_t reg_base;
> +
> +	node = of_find_compatible_node(NULL, NULL, "arm,pl111");
> +	if (!node)
> +		return -ENODEV;
> +
> +	na = of_n_addr_cells(node);
> +	ns = of_n_size_cells(node);
> +
> +	prop = of_get_property(node, "reg", &len);
> +	if (WARN_ON(!prop || len < (na + ns) * sizeof(*prop)))
> +		return -EINVAL;
> +	reg_base = of_read_number(prop, na);
> +
> +	switch (reg_base) {
> +	case CT_CA9X4_CLCDC:
> +		clcd_site = v2m_get_master_site();
> +		dvimode = 2;
> +		break;
> +	default:
> +		clcd_site = SYS_CFG_SITE_MB;
> +		dvimode = 0;
> +		break;
> +	}
> +
> +	if (of_property_read_u32(node, "arm,vexpress-osc", &osc) != 0)
> +		return -EINVAL;
> +	v2m_dt_clcd_osc.site = clcd_site;
> +	v2m_dt_clcd_osc.osc = osc;
> +	v2m_cfg_write(SYS_CFG_MUXFPGA | clcd_site, clcd_site);
> +	v2m_cfg_write(SYS_CFG_DVIMODE | clcd_site, dvimode);
> +	return 0;
> +}
> +
>  static struct map_desc v2m_rs1_io_desc __initdata = {
>  	.virtual	= V2M_PERIPH,
>  	.pfn		= __phys_to_pfn(0x1c000000),
> @@ -598,6 +648,8 @@ void __init v2m_dt_init_early(void)
>  			pr_warning("vexpress: DT HBI (%x) is not matching "
>  					"hardware (%x)!\n", dt_hbi, hbi);
>  	}
> +
> +	v2m_dt_clcd_init();
>  }
>  
>  static  struct of_device_id vexpress_irq_match[] __initdata = {
> @@ -631,6 +683,12 @@ static void __init v2m_dt_timer_init(void)
>  
>  	if (arch_timer_sched_clock_init() != 0)
>  		versatile_sched_clock_init(v2m_sysreg_base + V2M_SYS_24MHZ, 24000000);
> +
> +	if (v2m_dt_clcd_osc.site) {
> +		/* core tile clcd controller for A9 */
> +		clk = v2m_osc_register("10020000.clcd", &v2m_dt_clcd_osc);
> +		clk_register_clkdev(clk, NULL, "10020000.clcd");
> +	}
>  }
>  
>  static struct sys_timer v2m_dt_timer = {

When (if ;-) the changes I proposed recently make their way into
mainline, all this stuff will not be necessary - both clocking and
display control are sorted there.

Pawel