On 06/11/2012 09:27 AM, Afzal Mohammed wrote:
> GPMC has a writeprotect pin that can be connected to
> peripherals. If any CS wants to enable writeprotect,
> writeprotect will be enabled, once CS configurations
> are finished.
I am still wondering if we should warn against multiple devices using
the wait pin. I see that if could be valid to have multiple memory
devices of the same type using the WP pin spanning multiple CS. However,
in that case would/should the memory devices be registered as a single
child? If so then we could still impose a policy of only one child
device using the WP.
Jon
> Signed-off-by: Afzal Mohammed <afzal@xxxxxx>
> ---
> arch/arm/mach-omap2/gpmc.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
> index 98b52c3..eec011a 100644
> --- a/arch/arm/mach-omap2/gpmc.c
> +++ b/arch/arm/mach-omap2/gpmc.c
> @@ -159,6 +159,7 @@ struct gpmc_peripheral {
> static struct gpmc_peripheral gpmc_peripheral[GPMC_CS_NUM];
> static unsigned gpmc_num_peripheral;
> static unsigned gpmc_waitpin_map;
> +static bool gpmc_writeprotect;
>
> static struct gpmc_client_irq gpmc_client_irq[GPMC_NR_IRQ];
> static struct irq_chip gpmc_irq_chip;
> @@ -976,6 +977,9 @@ static void gpmc_setup_cs_config(unsigned cs, unsigned conf)
> else if (conf & GPMC_CONFIG1_PAGE_LEN_16)
> l |= GPMC_CONFIG1_PAGE_LEN_16;
>
> + if (conf & GPMC_CONFIG_WRITEPROTECT)
> + gpmc_writeprotect = true;
> +
> conf &= (GPMC_CONFIG1_MUXADDDATA |
> GPMC_CONFIG1_WRITETYPE_SYNC |
> GPMC_CONFIG1_WRITEMULTIPLE_SUPP |
> @@ -1462,6 +1466,19 @@ int gpmc_cs_reconfigure(char *name, int id, struct gpmc_cs_data *c)
> }
> EXPORT_SYMBOL_GPL(gpmc_cs_reconfigure);
>
> +static inline void gpmc_setup_writeprotect(void)
> +{
> + u32 l;
> +
> + l = gpmc_read_reg(GPMC_CONFIG);
> + if (gpmc_writeprotect == true) {
> + l &= ~GPMC_CONFIG_WRITEPROTECT;
> + dev_info(gpmc_dev, "write protect enabled\n");
> + } else
> + l |= GPMC_CONFIG_WRITEPROTECT;
> + gpmc_write_reg(GPMC_CONFIG, l);
> +}
> +
> static __devinit int gpmc_probe(struct platform_device *pdev)
> {
> u32 l;
> @@ -1521,6 +1538,8 @@ static __devinit int gpmc_probe(struct platform_device *pdev)
> dev_err(gpmc_dev, "device creation on %s failed\n",
> g_per->name);
>
> + gpmc_setup_writeprotect();
> +
> return 0;
> }
>
> @@ -1531,6 +1550,7 @@ static __exit int gpmc_remove(struct platform_device *pdev)
> for (; gpmc_num_peripheral; g_per++, gpmc_num_peripheral--)
> platform_device_unregister(g_per->pdev);
>
> + gpmc_writeprotect = false;
> gpmc_waitpin_map = 0;
> gpmc_free_irq();
> gpmc_mem_exit();
--
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