Re: [PATCH] powerpc/512x: add function for CS parameter configuration
From: Timur Tabi <hidden>
Date: 2013-02-02 04:38:12
On Fri, Feb 1, 2013 at 7:28 AM, Anatolij Gustschin [off-list ref] wrote:
Add ability to configure CS parameters for devices that need different CS parameters setup after their configuration. I.e. an FPGA device on LP bus can require different CS parameters for its bus interface after loading firmware into it. A driver can easily reconfigure the LPC CS parameters using this function.
Could you define "CS" somewhere?
+struct mpc512x_lpc {
+ u32 cs_cfg[8]; /* CS config */
+ u32 cs_ctrl; /* CS Control Register */
+ u32 cs_status; /* CS Status Register */
+ u32 burst_ctrl; /* CS Burst Control Register */
+ u32 deadcycle_ctrl; /* CS Deadcycle Control Register */
+ u32 holdcycle_ctrl; /* CS Holdcycle Control Register */
+ u32 alt; /* Address Latch Timing Register */
+};These should be __be32.
quoted hunk ↗ jump to hunk
+ +int mpc512x_cs_config(int cs, u32 val); + #endif /* __ASM_POWERPC_MPC5121_H__ */diff --git a/arch/powerpc/platforms/512x/mpc512x_shared.c b/arch/powerpc/platforms/512x/mpc512x_shared.c index c344438..112b4f6 100644 --- a/arch/powerpc/platforms/512x/mpc512x_shared.c +++ b/arch/powerpc/platforms/512x/mpc512x_shared.c@@ -436,3 +436,33 @@ void __init mpc512x_init(void) mpc512x_restart_init(); mpc512x_psc_fifo_init(); } + +/** + * mpc512x_cs_config - Setup chip select configuration + * @cs: chip select number + * @val: chip select configuration value + * + * Perform chip select configuration for devices on LocalPlus Bus. + * Intended to dynamically reconfigure the chip select parameters + * for configurable devices on the bus. + */ +int mpc512x_cs_config(int cs, u32 val) +{ + static struct mpc512x_lpc __iomem *lpc; + struct device_node *np; + + if (cs < 0 || cs > 7) + return -EINVAL;
If you make cs an unsigned int, you won't need to test for < 0.
+
+ if (!lpc) {
+ np = of_find_compatible_node(NULL, NULL, "fsl,mpc5121-lpc");
+ lpc = of_iomap(np, 0);
+ of_node_put(np);
+ if (!lpc)
+ return -ENOMEM;
+ }
+
+ out_be32(&lpc->cs_cfg[cs], val);You forgot the iounmap() if lpc == NULL.
+ return 0; +} +EXPORT_SYMBOL_GPL(mpc512x_cs_config);
EXPORT_SYMBOL, please, to match the rest of the Freescale platforms. -- Timur Tabi Linux kernel developer at Freescale