Thread (10 messages) 10 messages, 7 authors, 2007-02-12

Re: [PATCH] mfd: SM501 core driver

From: Ben Dooks <ben-linux@fluff.org>
Date: 2007-02-07 11:48:47
Also in: lkml

On Tue, Feb 06, 2007 at 09:09:30PM -0800, Andrew Morton wrote:
On Tue, 6 Feb 2007 19:26:28 +0000 Ben Dooks [off-list ref] wrote:
quoted
This patch is an update patch, ready for merging
for the Silicon Motion SM501 multi-function device
core.

This driver handles the core function of the chip,
including the clock, power control and allocation
of resources for drivers. It also exports a series
of platform devices for the function drivers to
attach to.

This patch supports both platform and PCI bus
attached devices.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Can we get Vincent's signoff here?
quoted
+#ifdef CONFIG_DEBUG
This doesn't appear to be defined anywhere, and nor should it be. 
Something subsystem-specific should be used here?
This protects the code being used by dev_dbg() only from being
warned as not being used.
 
quoted
+static const unsigned int misc_div[] = {
+	[0]		= 1,
+	[1]		= 2,
+	[2]		= 4,
+	[3]		= 8,
+	[4]		= 16,
+	[5]		= 32,
+	[6]		= 64,
+	[7]		= 128,
+	[8]		= 3,
+	[9]		= 6,
+	[10]		= 12,
+	[11]		= 24,
+	[12]		= 48,
+	[13]		= 96,
+	[14]		= 192,
+	[15]		= 384,
+};
+
+static const unsigned int px_div[] = {
+	[0]		= 1,
+	[1]		= 2,
+	[2]		= 4,
+	[3]		= 8,
+	[4]		= 16,
+	[5]		= 32,
+	[6]		= 64,
+	[7]		= 128,
+	[8]		= 3,
+	[9]		= 6,
+	[10]	        = 12,
+	[11]		= 24,
+	[12]		= 48,
+	[13]		= 96,
+	[14]		= 192,
+	[15]		= 384,
+	[16]		= 5,
+	[17]		= 10,
+	[18]		= 20,
+	[19]		= 40,
+	[20]		= 80,
+	[21]		= 160,
+	[22]		= 320,
+	[23]		= 604,
+};
+#endif
+
+#define decode_div(val, lshft, selbit, mask, dtab) \
+	((((val) & (selbit)) ? pll2 : 288 * MHZ) / dtab[(((val) >> (lshft)) & (mask))])
A C function would be nicer here, if poss.
quoted
+#define fmt_freq(x) ((x) / MHZ), ((x) % MHZ), (x)
eww.
Do you have a better way of printing a nice formatted MHz with
fractional parts? Is it going to be necessary to remove this?
quoted
+		(void)readl(sm->regs);
Is there any benefit in all those casts?  Generally we prefer to avoid
them.
I thoguht they where necessary to stop the compiler optimising
away the readl() ?
 
quoted
+EXPORT_SYMBOL_GPL(sm501_misc_control);
The driver exports a lot of symbols.  Does it really need to?
Yes, these are used by the drivers for the specific function
blocks in the chip.
 
quoted
+	down(&sm->clock_lock);
Please convert to a mutex, if possible.
The current callers are the device initialisation and ioctl() calls
from the framebuffer layer. I expect all the other callers to be from
ioctl() calls (to update device parameters) or possibly from sysfs
file interaction, so I think that a mutex may be okay for this.
 
quoted
+/* sm501_null_release
+ *
+ * A release function for the platform devices we create to keep the
+ * driver core happy, and stop any crashed when the devices are removed
+*/
+
+static void sm501_null_release(struct device *dev)
+{
+}
Greg might have an opinion on that ;)
Without this the system OOPses when the driver is removed.
 
quoted
+static void sm501_create_mem(struct sm501_devdata *sm,
+			     struct resource *res,
+			     unsigned long *offs,
+			     unsigned long size)
+{
+	*offs -= size;		/* adjust memory size */
+
+	res->flags = IORESOURCE_MEM;
+	res->parent = sm->mem_res;
+	res->start = sm->mem_res->start + *offs;
+	res->end = res->start + size - 1;
+}
Please use resource_size_t throughout, test with CONFIG_RESOURCES_64BIT on
and off.
I will go and fix this.5~
 
quoted
+static inline void sm501_init_reg(struct sm501_devdata *sm,
+				  unsigned long reg,
+				  struct sm501_reg_init *r)
+{
+	unsigned long tmp;
+
+	tmp = readl(sm->regs + reg);
+	tmp |= r->set;
+	tmp &= ~r->mask;
+	writel(tmp, sm->regs + reg);
+}
This might be too large to inline.
possibly.

-- 
Ben (ben@fluff.org, http://www.fluff.org/)

  'a smiley only costs 4 bytes'

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