[PATCH 10/16] pata_parport: add epia protocol driver

Ondrej Zary
2022-03-05T20:15:31Z

Add Shuttle EPIA protocol driver.

Signed-off-by: Ondrej Zary <linux@zary.sk>
---
drivers/ata/pata_parport/Kconfig | 11 ++
drivers/ata/pata_parport/Makefile | 1 +
drivers/ata/pata_parport/epia.c | 308 ++++++++++++++++++++++++++++++
3 files changed, 320 insertions(+)
create mode 100644 drivers/ata/pata_parport/epia.c

diff --git a/drivers/ata/pata_parport/Kconfig b/drivers/ata/pata_parport/Kconfig
index 6c218486c3b8..832ab8b00511 100644
--- a/drivers/ata/pata_parport/Kconfig
+++ b/drivers/ata/pata_parport/Kconfig
@@ -109,3 +109,14 @@ config PATA_PARPORT_EPAT
PATA_PARPORT support into your kernel, you may answer Y here to build in
the protocol driver, otherwise you should answer M to build it as a
loadable module. The module will be called epat.
+
+config PATA_PARPORT_EPIA
+ tristate "Shuttle EPIA protocol"
+ depends on PATA_PARPORT
+ help
+ This option enables support for the (obsolete) EPIA parallel port
+ IDE protocol from Shuttle Technology. This adapter can still be
+ found in some no-name kits. If you chose to build PATA_PARPORT support
+ into your kernel, you may answer Y here to build in the protocol
+ driver, otherwise you should answer M to build it as a loadable
+ module. The module will be called epia.
diff --git a/drivers/ata/pata_parport/Makefile b/drivers/ata/pata_parport/Makefile
index 459307f4a096..6e72778f45cb 100644
--- a/drivers/ata/pata_parport/Makefile
+++ b/drivers/ata/pata_parport/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_PATA_PARPORT_DSTR) += dstr.o
obj-$(CONFIG_PATA_PARPORT_FIT2) += fit2.o
obj-$(CONFIG_PATA_PARPORT_FIT3) += fit3.o
obj-$(CONFIG_PATA_PARPORT_EPAT) += epat.o
+obj-$(CONFIG_PATA_PARPORT_EPIA) += epia.o
diff --git a/drivers/ata/pata_parport/epia.c b/drivers/ata/pata_parport/epia.c
new file mode 100644
index 000000000000..7f3db02fd243
--- /dev/null
+++ b/drivers/ata/pata_parport/epia.c
@@ -0,0 +1,308 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * epia.c (c) 1997-8 Grant R. Guenther <grant@torque.net>
+ * Under the terms of the GNU General Public License.
+ *
+ * epia.c is a low-level protocol driver for Shuttle Technologies
+ * EPIA parallel to IDE adapter chip. This device is now obsolete
+ * and has been replaced with the EPAT chip, which is supported
+ * by epat.c, however, some devices based on EPIA are still
+ * available.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+#include <linux/io.h>
+
+#include "pata_parport.h"
+
+/* mode codes: 0 nybble reads on port 1, 8-bit writes
+ * 1 5/3 reads on ports 1 & 2, 8-bit writes
+ * 2 8-bit reads and writes
+ * 3 8-bit EPP mode
+ * 4 16-bit EPP
+ * 5 32-bit EPP
+ */
+
+#define j44(a, b) (((a >> 4) & 0x0f) + (b & 0xf0))
+#define j53(a, b) (((a >> 3) & 0x1f) + ((b << 4) & 0xe0))
+
+/* cont = 0 IDE register file
+ * cont = 1 IDE control registers
+ */
+
+static int cont_map[2] = { 0, 0x80 };
+
+static int epia_read_regr(struct pi_adapter *pi, int cont, int regr)
+{
+ int a, b, r;
+
+ regr += cont_map[cont];
+
+ switch (pi->mode) {
+ case 0:
+ r = regr ^ 0x39;
+ w0(r); w2(1); w2(3); w0(r);
+ a = r1(); w2(1); b = r1(); w2(4);
+ return j44(a, b);
+ case 1:
+ r = regr ^ 0x31;
+ w0(r); w2(1); w0(r&0x37);
+ w2(3); w2(5); w0(r|0xf0);
+ a = r1(); b = r2(); w2(4);
+ return j53(a, b);
+ case 2:
+ r = regr ^ 0x29;
+ w0(r); w2(1); w2(0X21); w2(0x23);
+ a = r0(); w2(4);
+ return a;
+ case 3:
+ case 4:
+ case 5:
+ w3(regr); w2(0x24); a = r4(); w2(4);
+ return a;
+ }
+ return -1;
+}
+
+static void epia_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
+{
+ int r;
+
+ regr += cont_map[cont];
+
+ switch (pi->mode) {
+ case 0:
+ case 1:
+ case 2:
+ r = regr ^ 0x19;
+ w0(r); w2(1); w0(val); w2(3); w2(4);
+ break;
+ case 3:
+ case 4:
+ case 5:
+ r = regr ^ 0x40;
+ w3(r); w4(val); w2(4);
+ break;
+ }
+}
+
+#define WR(r, v) epia_write_regr(pi, 0, r, v)
+#define RR(r) (epia_read_regr(pi, 0, r))
+
+/* The use of register 0x84 is entirely unclear - it seems to control
+ * some EPP counters ... currently we know about 3 different block
+ * sizes: the standard 512 byte reads and writes, 12 byte writes and
+ * 2048 byte reads (the last two being used in the CDrom drivers.
+ */
+
+static void epia_connect(struct pi_adapter *pi)
+{
+ pi->saved_r0 = r0();
+ pi->saved_r2 = r2();
+
+ w2(4); w0(0xa0); w0(0x50); w0(0xc0); w0(0x30); w0(0xa0); w0(0);
+ w2(1); w2(4);
+ if (pi->mode >= 3) {
+ w0(0xa); w2(1); w2(4); w0(0x82); w2(4); w2(0xc); w2(4);
+ w2(0x24); w2(0x26); w2(4);
+ }
+ WR(0x86, 8);
+}
+
+static void epia_disconnect(struct pi_adapter *pi)
+{
+ /* WR(0x84, 0x10); */
+ w0(pi->saved_r0);
+ w2(1); w2(4);
+ w0(pi->saved_r0);
+ w2(pi->saved_r2);
+}
+
+static void epia_read_block(struct pi_adapter *pi, char *buf, int count)
+{
+ int k, ph, a, b;
+
+ switch (pi->mode) {
+ case 0:
+ w0(0x81); w2(1); w2(3); w0(0xc1);
+ ph = 1;
+ for (k = 0; k < count; k++) {
+ w2(2 + ph); a = r1();
+ w2(4 + ph); b = r1();
+ buf[k] = j44(a, b);
+ ph = 1 - ph;
+ }
+ w0(0); w2(4);
+ break;
+ case 1:
+ w0(0x91); w2(1); w0(0x10); w2(3);
+ w0(0x51); w2(5); w0(0xd1);
+ ph = 1;
+ for (k = 0; k < count; k++) {
+ w2(4 + ph);
+ a = r1(); b = r2();
+ buf[k] = j53(a, b);
+ ph = 1 - ph;
+ }
+ w0(0); w2(4);
+ break;
+ case 2:
+ w0(0x89); w2(1); w2(0x23); w2(0x21);
+ ph = 1;
+ for (k = 0; k < count; k++) {
+ w2(0x24 + ph);
+ buf[k] = r0();
+ ph = 1 - ph;
+ }
+ w2(6); w2(4);
+ break;
+ case 3:
+ if (count > 512)
+ WR(0x84, 3);
+ w3(0); w2(0x24);
+ for (k = 0; k < count; k++)
+ buf[k] = r4();
+ w2(4); WR(0x84, 0);
+ break;
+ case 4:
+ if (count > 512)
+ WR(0x84, 3);
+ w3(0); w2(0x24);
+ for (k = 0; k < count / 2; k++)
+ ((u16 *)buf)[k] = r4w();
+ w2(4); WR(0x84, 0);
+ break;
+ case 5:
+ if (count > 512)
+ WR(0x84, 3);
+ w3(0); w2(0x24);
+ for (k = 0; k < count / 4; k++)
+ ((u32 *)buf)[k] = r4l();
+ w2(4); WR(0x84, 0);
+ break;
+ }
+}
+
+static void epia_write_block(struct pi_adapter *pi, char *buf, int count)
+{
+ int ph, k, last, d;
+
+ switch (pi->mode) {
+ case 0:
+ case 1:
+ case 2:
+ w0(0xa1); w2(1); w2(3); w2(1); w2(5);
+ ph = 0; last = 0x8000;
+ for (k = 0; k < count; k++) {
+ d = buf[k];
+ if (d != last) {
+ last = d; w0(d);
+ }
+ w2(4 + ph);
+ ph = 1 - ph;
+ }
+ w2(7); w2(4);
+ break;
+ case 3:
+ if (count < 512)
+ WR(0x84, 1);
+ w3(0x40);
+ for (k = 0; k < count; k++)
+ w4(buf[k]);
+ if (count < 512)
+ WR(0x84, 0);
+ break;
+ case 4:
+ if (count < 512)
+ WR(0x84, 1);
+ w3(0x40);
+ for (k = 0; k < count / 2; k++)
+ w4w(((u16 *)buf)[k]);
+ if (count < 512)
+ WR(0x84, 0);
+ break;
+ case 5:
+ if (count < 512)
+ WR(0x84, 1);
+ w3(0x40);
+ for (k = 0; k < count / 4; k++)
+ w4l(((u32 *)buf)[k]);
+ if (count < 512)
+ WR(0x84, 0);
+ break;
+ }
+}
+
+static int epia_test_proto(struct pi_adapter *pi, char *scratch, int verbose)
+{
+ int j, k, f;
+ int e[2] = { 0, 0 };
+
+ epia_connect(pi);
+ for (j = 0; j < 2; j++) {
+ WR(6, 0xa0 + j * 0x10);
+ for (k = 0; k < 256; k++) {
+ WR(2, k ^ 0xaa);
+ WR(3, k ^ 0x55);
+ if (RR(2) != (k ^ 0xaa))
+ e[j]++;
+ }
+ WR(2, 1); WR(3, 1);
+ }
+ epia_disconnect(pi);
+
+ f = 0;
+ epia_connect(pi);
+ WR(0x84, 8);
+ epia_read_block(pi, scratch, 512);
+ for (k = 0; k < 256; k++) {
+ if ((scratch[2 * k] & 0xff) != ((k + 1) & 0xff))
+ f++;
+ if ((scratch[2 * k + 1] & 0xff) != ((-2 - k) & 0xff))
+ f++;
+ }
+ WR(0x84, 0);
+ epia_disconnect(pi);
+
+ if (verbose)
+ dev_info(&pi->dev, "epia: port 0x%x, mode %d, test=(%d,%d,%d)\n",
+ pi->port, pi->mode, e[0], e[1], f);
+
+ return (e[0] && e[1]) || f;
+}
+
+
+static void epia_log_adapter(struct pi_adapter *pi, char *scratch, int verbose)
+{
+ static char * const mode_string[] = {
+ "4-bit", "5/3", "8-bit", "EPP-8", "EPP-16", "EPP-32" };
+
+ dev_info(&pi->dev, "epia, Shuttle EPIA at 0x%x, mode %d (%s), delay %d\n",
+ pi->port, pi->mode, mode_string[pi->mode], pi->delay);
+}
+
+static struct pi_protocol epia = {
+ .owner = THIS_MODULE,
+ .name = "epia",
+ .max_mode = 6,
+ .epp_first = 3,
+ .default_delay = 1,
+ .max_units = 1,
+ .write_regr = epia_write_regr,
+ .read_regr = epia_read_regr,
+ .write_block = epia_write_block,
+ .read_block = epia_read_block,
+ .connect = epia_connect,
+ .disconnect = epia_disconnect,
+ .test_proto = epia_test_proto,
+ .log_adapter = epia_log_adapter,
+ .sht = { PATA_PARPORT_SHT("pata_parport-epia") },
+};
+
+MODULE_LICENSE("GPL");
+module_pata_parport_driver(epia);
--
Ondrej Zary