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powerpc: Move CPM command handling into the cpm drivers

RFC/PATCHv2 Jochen Friedrich 2 participants 2 messages Nov 24, 2007

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#0 lore raw

This patch moves the CPM command handling into commproc.c for CPM1 and cpm2_common.c. This is yet another preparation to get rid of drivers accessing the CPM via the global cpmp.

---

arch/powerpc/sysdev/commproc.c          |   27 +++++++++++++++++++++++++++
arch/powerpc/sysdev/cpm2_common.c       |   24 ++++++++++++++++++++++++
drivers/net/fs_enet/mac-fcc.c           |   10 +---------
drivers/net/fs_enet/mac-scc.c           |   11 +----------
drivers/serial/cpm_uart/cpm_uart_cpm1.c |    6 +-----
drivers/serial/cpm_uart/cpm_uart_cpm2.c |    8 +-------
include/asm-powerpc/cpm.h               |    1 +
7 files changed, 56 insertions(+), 31 deletions(-)
arch/powerpc/sysdev/commproc.c +0 -0
index f6a6378..4cc245f 100644
@@ -240,6 +240,33 @@ void __init cpm_reset(void)

#endif
}

+DEFINE_SPINLOCK(cmd_lock);
+
+#define MAX_CR_CMD_LOOPS 10000
+
+int cpm_command(u32 command, u8 opcode)
+{
+ int i;
+ unsigned long flags;
+
+ if (command & 0xffffff0f)
+ return -EINVAL;
+
+ spin_lock_irqsave(&cmd_lock, flags);
+
+ out_be16(&cpmp->cp_cpcr, command | CPM_CR_FLG | (opcode << 8));
+ for (i = 0; i < MAX_CR_CMD_LOOPS; i++)
+ if ((in_be16(&cpmp->cp_cpcr) & CPM_CR_FLG) == 0) {
+ spin_unlock_irqrestore(&cmd_lock, flags);
+ return 0;
+ }
+
+ printk(KERN_ERR "%s(): Not able to issue CPM command\n", __FUNCTION__);
+ spin_unlock_irqrestore(&cmd_lock, flags);
+ return -EIO;
+}
+EXPORT_SYMBOL(cpm_command);
+
/* We used to do this earlier, but have to postpone as long as possible
* to ensure the kernel VM is now running.
*/

arch/powerpc/sysdev/cpm2_common.c +0 -0
index 859362f..db282bc 100644
@@ -83,6 +83,30 @@ cpm2_reset(void)
	cpmp = &cpm2_immr->im_cpm;
}

+DEFINE_SPINLOCK(cmd_lock);
+
+#define MAX_CR_CMD_LOOPS 10000
+
+int cpm_command(u32 command, u8 opcode)
+{
+ int i;
+ unsigned long flags;
+
+ spin_lock_irqsave(&cmd_lock, flags);
+
+ out_be32(&cpmp->cp_cpcr, command | opcode | CPM_CR_FLG);
+ for (i = 0; i < MAX_CR_CMD_LOOPS; i++)
+ if ((in_be32(&cpmp->cp_cpcr) & CPM_CR_FLG) == 0) {
+ spin_unlock_irqrestore(&cmd_lock, flags);
+ return 0;
+ }
+
+ printk(KERN_ERR "%s(): Not able to issue CPM command\n", __FUNCTION__);
+ spin_unlock_irqrestore(&cmd_lock, flags);
+ return -EIO;
+}
+EXPORT_SYMBOL(cpm_command);
+
/* Set a baud rate generator. This needs lots of work. There are
* eight BRGs, which can be connected to the CPM channels or output
* as clocks. The BRGs are in two different block of internal

drivers/net/fs_enet/mac-fcc.c +0 -0
index da4efbc..e363211 100644
@@ -81,16 +81,8 @@

static inline int fcc_cr_cmd(struct fs_enet_private *fep, u32 op)

{
	const struct fs_platform_info *fpi = fep->fpi;

- int i;
-
- W32(cpmp, cp_cpcr, fpi->cp_command | op | CPM_CR_FLG);
- for (i = 0; i < MAX_CR_CMD_LOOPS; i++)
- if ((R32(cpmp, cp_cpcr) & CPM_CR_FLG) == 0)
- return 0;

- printk(KERN_ERR "%s(): Not able to issue CPM command\n",
- __FUNCTION__);
- return 1;
+ return cpm_command(fpi->cp_command, op);
}

static int do_pd_setup(struct fs_enet_private *fep)

drivers/net/fs_enet/mac-scc.c +0 -0
index 03134f4..5ff856d 100644
@@ -89,21 +89,12 @@
 * Delay to wait for SCC reset command to complete (in us)
 */

#define SCC_RESET_DELAY 50
-#define MAX_CR_CMD_LOOPS 10000

static inline int scc_cr_cmd(struct fs_enet_private *fep, u32 op)

{
	const struct fs_platform_info *fpi = fep->fpi;

- int i;
-
- W16(cpmp, cp_cpcr, fpi->cp_command | CPM_CR_FLG | (op << 8));
- for (i = 0; i < MAX_CR_CMD_LOOPS; i++)
- if ((R16(cpmp, cp_cpcr) & CPM_CR_FLG) == 0)
- return 0;

- printk(KERN_ERR "%s(): Not able to issue CPM command\n",
- __FUNCTION__);
- return 1;
+ return cpm_command(fpi->cp_command, op);
}

static int do_pd_setup(struct fs_enet_private *fep)

drivers/serial/cpm_uart/cpm_uart_cpm1.c +0 -0
index 52fb044..6ea0366 100644
@@ -52,11 +52,7 @@

#ifdef CONFIG_PPC_CPM_NEW_BINDING
void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd) {
- u16 __iomem *cpcr = &cpmp->cp_cpcr;
-
- out_be16(cpcr, port->command | (cmd << 8) | CPM_CR_FLG);
- while (in_be16(cpcr) & CPM_CR_FLG)
- ;
+ cpm_command(port->command, cmd);
}
#else
void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)

drivers/serial/cpm_uart/cpm_uart_cpm2.c +0 -0
index 882dbc1..def0158 100644
@@ -52,13 +52,7 @@

#ifdef CONFIG_PPC_CPM_NEW_BINDING
void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd) {
- cpm_cpm2_t __iomem *cp = cpm2_map(im_cpm);
-
- out_be32(&cp->cp_cpcr, port->command | cmd | CPM_CR_FLG);
- while (in_be32(&cp->cp_cpcr) & CPM_CR_FLG)
- ;
-
- cpm2_unmap(cp);
+ cpm_command(port->command, cmd);
}
#else
void cpm_line_cr_cmd(struct uart_cpm_port *port, int cmd)

include/asm-powerpc/cpm.h +0 -0
index 48df9f3..fae83b1 100644
@@ -10,5 +10,6 @@ int cpm_muram_free(unsigned long offset);

unsigned long cpm_muram_alloc_fixed(unsigned long offset, unsigned long size); void __iomem *cpm_muram_addr(unsigned long offset);
dma_addr_t cpm_muram_dma(void __iomem *addr);
+int cpm_command(u32 command, u8 opcode);

#endif

Signature · 1 line
1.5.3.5
#1 lore raw
Quoted 3 lines · Jochen Friedrich

This patch moves the CPM command handling into commproc.c for CPM1 and cpm2_common.c. This is yet another preparation to get rid of drivers accessing the CPM via the global cpmp.

good stuff, just a little nitpicking below:

Quoted 1 line

+DEFINE_SPINLOCK(cmd_lock);

This should probably be a static variable. The name is too generic for a global identifier. If every use of the command register goes through the cpm_command function, you could even make it a static variable in that function.

Quoted 6 lines
(quoted diff) +6 -0
+int cpm_command(u32 command, u8 opcode)
+{
+	int i;
+	unsigned long flags;
+
+	if (command & 0xffffff0f)

Review

Quoted 10 lines
(quoted diff) +10 -0
+		return -EINVAL;
+
+	spin_lock_irqsave(&cmd_lock, flags);
+
+	out_be16(&cpmp->cp_cpcr, command | CPM_CR_FLG | (opcode << 8));
+	for (i = 0; i < MAX_CR_CMD_LOOPS; i++)
+		if ((in_be16(&cpmp->cp_cpcr) & CPM_CR_FLG) == 0) {
+			spin_unlock_irqrestore(&cmd_lock, flags);
+			return 0;
+		}

Error handling in here is nicer if you do a goto that jumps to the unlock below. If the code ever gets more complex, this makes it easier to check if it's correct regarding locking.

Review

Quoted 5 lines
(quoted diff) +5 -0
+	printk(KERN_ERR "%s(): Not able to issue CPM command\n", __FUNCTION__);
+	spin_unlock_irqrestore(&cmd_lock, flags);
+	return -EIO;
+}
+EXPORT_SYMBOL(cpm_command);

Why not EXPORT_SYMBOL_GPL?

Quoted 1 line

+DEFINE_SPINLOCK(cmd_lock);

see above

Quoted 12 lines
(quoted diff) +12 -0
+
+#define MAX_CR_CMD_LOOPS        10000
+
+int cpm_command(u32 command, u8 opcode)
+{
+	int i;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmd_lock, flags);
+
+	out_be32(&cpmp->cp_cpcr, command | opcode | CPM_CR_FLG);
+	for (i = 0; i < MAX_CR_CMD_LOOPS; i++)

Review

Quoted 10 lines
(quoted diff) +10 -0
+		if ((in_be32(&cpmp->cp_cpcr) & CPM_CR_FLG) == 0) {
+			spin_unlock_irqrestore(&cmd_lock, flags);
+			return 0;
+		}
+
+	printk(KERN_ERR "%s(): Not able to issue CPM command\n", __FUNCTION__);
+	spin_unlock_irqrestore(&cmd_lock, flags);
+	return -EIO;
+}
+EXPORT_SYMBOL(cpm_command);

see above

	Arnd <><